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Background: Chlamydia trachomatis is a common sexually transmitted disease that is associated with considerable morbidity and harmful sequelae, including pelvic inflammatory disease and infertility. Strategies for prevention and treatment of infertility in women with C. trachomatis infection require further investigation. There is evidence suggesting that vitamin D could be a potential treatment. This study aimed to investigate the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels, chlamydia seropositivity, and the risk of infertility in women. Methods: We conducted this cross-sectional study using 2013–2016 National Health and Nutrition Examination Survey data. Women aged 18–39 years with complete serum 25(OH)D and chlamydia Pgp3Ab multiplex bead/enzyme-linked immunosorbent assay data available were included. The correlation between 25(OH)D level, chlamydia seropositivity, and infertility was evaluated using the weighted chi-squared test and the t-test with multivariate logistic regression and moderation effect models. Results: Among the 1424 women who met our eligibility criteria, the weighted chlamydia seropositivity rate was 36.8%. The 25(OH)D level was significantly lower in the seropositive group compared with seronegative control. (P = 0.009). After adjusting for ethnicity, the effect of 25(OH)D was no longer significant (P = 0.693). Further analysis in the chlamydia-seropositive subset revealed that the vitamin D level was lower in the infertile group (P = 0.024). In an interaction model, 25(OH)D was found to antagonizes the positive relationship between chlamydia and infertility (OR = 0.985, 95% CI: 0.971–0.999, P = 0.040). Conclusion: The serum vitamin D level may be more related to the prognosis in terms of infertility than to the risk of chlamydia infection. This finding may reveal a possible treatment strategy for chlamydia infection. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency has been linked to poor muscle function, cartilage degeneration, and the development of knee osteoarthritis. However, the impact of serum 25-hydroxyvitamin D [25(OH)D] level on quadriceps muscle strength remains inconclusive, largely due to variations in study designs, differences in study populations, and the influence of confounding factors such as co-supplementation with other vitamins. The existing literature presents mixed findings, highlighting the need for a comprehensive evaluation of the available evidence. Purpose: This systematic review and meta-analysis aim to summarise. Study design: Systematic review; Level of evidence, 4. Methods: Searches were conducted using Medline (Ovid), Embase (Ovid), CINAHL (EBSCOhost), and SPORTDiscus (EBSCOhost), which aimed to summarise recent (published after 2000 and before March 1st, 2024) studies reporting the effects of serum 25(OH)D levels on quadriceps strength. Appraisal tool for Cross-Sectional Studies (AXIS) for cross-sectional studies and Quality in Prognosis Studies (QUIPS) for longitudinal studies. Results from the AXIS and QUIPS tools were used for GRADE quality assessment. The review was carried out using PRIMSA guidelines and registered in PROSPERO (ID: CRD42022313240). Results: Four hundred studies were screened and 28 studies with 5752 participants were included. 28 published studies (24 cross-sectional and 4 longitudinal) were identified. Key results supported the significant positive correlation between serum 25(OH)D levels and isokinetic quadriceps strength at 180°/s in elderly and athletic populations with a correlation coefficient of 0.245 (95%CI: 0.078–0.398, p = 0.004). However, no significant correlation was found with isometric quadriceps strength or isokinetic strength at 60°/s (r = 0.190, p = 0.085). There was only a weak negative correlation with MVC. Conclusion: This review found a statistically significant positive correlation between serum 25(OH)D levels and isokinetic quadriceps strength. This has important clinical implications, especially in the elderly cohort, with higher 25(OH)D levels being associated with a reduced incidence of falls and fragility fractures. [ABSTRACT FROM AUTHOR]

Objective: The prevalence of type 2 diabetes mellitus (T2DM) and bone metabolism disorders increase with age. Diabetic kidney disease (DKD) is one of the most serious microvascular complications of T2DM, and bone metabolism disorders are closely linked to the occurrence of DKD. The relationship between bone turnover markers(BTMs) and the kidney disease in elderly patients with T2DM remains unclear. Therefore, this study aims to investigate the association between common BTMs and DKD in a large sample of elderly patients. The goal is to provide a basis for early identification of high-risk individuals for DKD among elderly T2DM patients from a bone metabolism perspective. Methods: In this cross-sectional study, BTMs were collected from a cohort of 2,051 hospitalized Chinese patients. The relationships between 25-hydroxyvitamin D (25-OH-D), β-CrossLaps (β-CTX), osteocalcin (OSTEOC), intact parathyroid hormone (iPTH), and total type I collagen N-terminal propeptide (TP1NP), and DKD, as well as urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) were analyzed using regression analysis and restrictive cubic spline (RCS) curves. Results: Higher 25-OH-D levels were independently linked to a lower incidence of DKD and decreased UACR. The RCS curves showed a linear association of 25-OH-D and DKD, approaching the L-shape. β-CTX was independently and positively correlated with UACR. There is an independent positive correlation between OSTEOC and UACR and a negative correlation with eGFR. iPTH is independently and positively correlated with DKD incidence and UACR, and negatively correlated with eGFR. Additionally, the RCS curves showed a non-linear association of OSTEOC and iPTH and DKD, approaching the J-shape, and the point of inflection is 10.875 ng/L and 34.15 pg/mL respectively. There is an independent positive correlation between TP1NP and UACR incidence, and a negative correlation with eGFR. Risk estimates significantly increase with higher TP1NP levels in the RCS model. Conclusion: BTMs are closely associated with kidney disease in elderly patients with T2DM. These discoveries potentially assist clinicians in establishing more preventive measures and targeted treatment strategies for elderly patients with T2DM. [ABSTRACT FROM AUTHOR]

Background: We aimed to probe the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among patients with gout and hyperuricemia (HUA). Methods: The study included 1169 gout patients and 7029 HUA patients from the National Health and Nutrition Examination Survey (NHANES) 2007–2018 and 2001–2018, respectively. The association between serum 25(OH)D and mortality was evaluated by Cox proportional hazard and restricted cubic spline models. Results: Among participants with gout and HUA, the weighted mean concentrations of serum 25(OH)D were 71.49 ± 30.09 nmol/L and 64.81 ± 26.92 nmol/L, respectively. Vitamin D deficiency occurred in 29.68% of gout patients and 37.83% of HUA patients. During 6783 person-years of follow-up among gout patients, 248 all-cause deaths occurred, among which 76 died from cardiovascular disease (CVD) and 49 died from cancer. 1375 HUA patients were recorded for all-cause mortality during 59,859 person-years of follow-up, including 427 CVD deaths and 232 cancer deaths. After multifactorial adjustment, per one-unit increment in natural log-transformed 25(OH)D was associated with lower risk of 55% all-cause mortality and 61% CVD mortality among gout patients, and a 45% reduced risk of cancer mortality among HUA patients. Restricted cubic splines showed a U-shaped relationship with all-cause and CVD mortality among HUA patients, with inflection points of 72.7 nmol/L and 38.0 nmol/L, respectively. The results were robust in subgroup and sensitivity analyses. Conclusions: Serum 25(OH)D was negatively linearly correlated with mortality among gout patients, whereas U-shaped correlated with mortality in HUA patients. These results indicate that adequate vitamin D status could prevent premature death. [ABSTRACT FROM AUTHOR]

Background: This review aims to substantiate the correlation between vitamin D and retinal vein occlusion (RVO) within the medical literature. Method: A systematic review and meta-analysis were conducted in PubMed, SCOPUS, Web of Science, and Embase until December 10th, 2023. A meticulous literature search was undertaken to identify and analyze all observational-analytical papers reporting vitamin D levels in RVO patients. The principal outcome measures centered on the comparative assessment of vitamin D levels between patients with RVO (cases) and those devoid of RVO (controls). The protocol was registered in PROSPERO (code: CRD42024499853). Results: A total of six relevant studies consisting of 589 participants were included in this meta-analysis. The results indicated a significant association between vitamin D deficiency and increased risk of RVO (Odds ratio = 14.51; 95% CI: [1.71, 122.59], P = 0.014); and patients with RVO exhibited a significant decrease in serum vitamin D levels by 1.91ng/mL (95% CI: [-2.29, -1.54], P < 0.001). Moreover, there was no significant difference observed in vitamin D levels between central RVO (CRVO) and branch RVO (BRVO) subtypes (P = 0.63). Conclusion: RVO patients have more vitamin D deficiency than healthy controls. These results contribute to the growing body of evidence highlighting the intricate role of vitamin D supplementation as both a prophylactic and a treatment strategy in RVO. PROSPERO registration identifier: : CRD42024499853. [ABSTRACT FROM AUTHOR]

Objective: We aimed to analyze the relationship between non-alcoholic fatty liver and progressive fibrosis and serum 25-hydroxy vitamin D (25(OH)D) in patients with type 2 diabetes mellitus. Methods: A total of 184 patients with T2DM who were hospitalized in the Department of Endocrinology of the ShiDong Clinical Hospital between January 2023 and June 2023 were selected. We compared review of anthropometric, biochemical, and inflammatory parameters and non-invasive scores between groups defined by ultrasound NAFLD severity grades.We determine the correlation between 25(OH)D and FLI and FIB-4 scores, respectively. Results: Statistically significant differences were seen between BMI, WC, C-peptide levels, FPG, ALT, serum 25(OH)D, TC, HDL, lumbar spine bone density, FLI, and FIB-4 in different degrees of NAFLD. Multivariate logistic regression analysis showed that 25(OH)D (OR = 1.26, p = 0.001), age (OR = 0.93, P < 0.001) and BMI (OR = 1.04, p = 0.007) were independent predictors of NAFLD in patients with T2DM. Conclusions: This study revealed the correlation between serum 25(OH)D levels and NAFLD in patients with T2DM. We also demonstrated that serum 25(OH)D levels were negatively correlated with FLI/FIB-4 levels in patients with T2DM with NAFLD, suggesting that vitamin D deficiency may promote hepatic fibrosis progression in T2DM with NAFLD. [ABSTRACT FROM AUTHOR]

Background: Adipose tissue is significantly involved in inflammatory bowel disease (IBD). Vitamin D can affect both adipogenesis and inflammation. The aim of this study was to compare the production of selected adipokines, potentially involved in the pathogenesis of IBD - adiponectin, resistin, retinol binding protein 4 (RBP-4), adipocyte fatty acid binding protein and nesfatin-1 in children with IBD according to the presence of 25-hydroxyvitamin D (25(OH)D) deficiency. Methods: The study was conducted as a case-control study in pediatric patients with IBD and healthy children of the same sex and age. In addition to adipokines and 25(OH)D, anthropometric parameters, markers of inflammation and disease activity were assessed in all participants. Results: Children with IBD had significantly higher resistin levels regardless of 25(OH)D levels. IBD patients with 25(OH)D deficiency only had significantly lower RBP-4 compared to healthy controls and also compared to IBD patients without 25(OH)D deficiency. No other significant differences in adipokines were found in children with IBD with or without 25(OH)D deficiency. 25(OH)D levels in IBD patients corelated with RBP-4 only, and did not correlate with other adipokines. Conclusions: Whether the lower RBP-4 levels in the 25(OH)D-deficient group of IBD patients directly reflect vitamin D deficiency remains uncertain. The production of other adipokines does not appear to be directly related to vitamin D deficiency. [ABSTRACT FROM AUTHOR]

Aim: The relationship between vitamin D status and Kawasaki Disease (KD), as well as coronary artery lesion (CAL), has yet to be established. Methods: A meta-analysis was conducted to assess the correlation between vitamin D status and KD, as well as the impact of vitamin D status on the progression of KD into CAL. Results: The meta-analysis revealed a consistent and significant association between serum 25(OH)D level and the occurrence KD (studies N = 22; z = -3.51, P < 0.001). Patients with KD had markedly lower levels of vitamin D than healthy controls (SMD: -1.30 ng/mL, 95%CI: -2.05 to -0.55 ng/mL). Conclusion: The study provided evidence supporting a significant association between lower serum vitamin D levels and the occurrence of KD, particularly within the Chinese population. However, the findings did not suggest a direct impact of vitamin D on the development of CAL in KD patients. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency is common among the population, but its relationship with mortality of postmenopausal females is unclear. The aim of this study is to explore the association between serum 25-Hydroxyvitamin D (25(OH)D) and all-cause and cause-specific mortality among postmenopausal women in the United States. Methods: 6812 participants of postmenopausal females from the National Health and Nutrition Examination Survey (2001–2018) were included in this study. The mortality status of the follow-up was ascertained by linkage to National Death Index (NDI) records through 31 December 2019. We used cox proportional hazards models to estimate the association of serum 25(OH)D concentrations and mortality of postmenopausal females. Results: The mean level of serum 25(OH)D was 72.57 ± 29.93 nmol/L, and 65.34% had insufficient vitamin D. In postmenopausal females, low serum 25(OH)D concentrations were significantly associated with higher levels of glycohemoglobin, glucose, and lower levels of HDL. During follow-up, 1448 all-cause deaths occurred, including 393 cardiovascular disease (CVD)-related deaths and 263 cancer deaths. After multivariate adjustment, higher serum 25(OH)D levels were significantly related with lower all-cause and CVD mortality. In addition, serum 25(OH)D presented a L-shaped relationship with all-cause mortality, while appeared a U-shaped with CVD mortality, and the cut-off value is 73.89 nmol/L and 46.75 nmol/L respectively. Conclusions: Low serum 25(OH)D levels are associated with the higher risk of all-cause and CVD mortality in postmenopausal females. These findings provide new ideas and targets for the health management of postmenopausal women. [ABSTRACT FROM AUTHOR]

Objective: This systematic review aimed to map the evidence evaluated the relationship between vitamin D and redox and inflammatory status during gestation. Methods: Three databases (PubMed/MEDLINE, Scopus, and Web of Science (WoS)) and reference list of included documents were searched for related observational studies published until 2nd October 2023. To determine the quality of the selected observational studies, the Newcastle-Ottawa Scale (NOS) was used. Results: After a primary search of three databases, 19492records were appeared. When duplicates and irrelevant documents were removed, 14 articles were found to have eligible criteria. The design of the identified studies was cross-sectional, case-control and cohort. Evidence showed an adverse association between 25(OH)D and the biomarkers of inflammation, such as high-sensitivity C-reactive protein (hs-CRP), Interleukin-1beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor- alfa (TNF-α) during pregnancy. On the contrary, some studies represented that 25(OH)D positively correlated with hs-CRP in the cord blood. One study suggested a direct association between serum concentrations of 25(OH)D and Interleukin-8 (IL-8), macrophage inflammatory protein (MIP), and TNF-α levels in mothers with gestational diabetes mellitus (GDM). A case-control study showed that lower serum concentration of 25(OH)D positively correlated with total antioxidant capacity (TAC) levels in participants. Conclusions: Evidence confirmed the supposition of the direct relationship between vitamin D levels and biomarkers with anti-inflammatory and anti-oxidative properties. However, the Existence of inconsistent evidence confirms the need for further studies in mothers with GDM and hypertensive disorders. PROSPERO registration code: CRD42020202600. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency (VDD) is a public health problem. The variation in vitamin D status across regions and populations remains unclear, and there is a lack of consensus regarding the screening for VDD in individuals. Methods: Children who visited the hospital from January 2019 to December 2020 were included in this study. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured using an enzyme-linked immunosorbent assay. The cutoffs for serum 25(OH)D concentrations to define deficiency, insufficiency, and sufficiency were < 20 ng/mL, 20–30 ng/mL, and ≥ 30 ng/mL, respectively. Results: A total of 7285 children aged 0–11 years were assessed; the mean 25(OH)D level was 31.4 ng/mL, and the median 25(OH)D level was 30.7 (interquartile range 24.4, 37.5) ng/mL. The 25(OH)D level declined with age in clinical visiting children aged 0–11 years, but maintained a consistently high level in health examination children aged 4–11 years. The percentages of 25(OH)D < 20 ng/mL and 25(OH)D < 30 ng/mL were 10.0% and 43.8%, respectively. Higher percentages of VDD were found in clinical visiting children than in health examination children within the 6–11-year group (53.3% vs. 14.7%) and winter (44.3% vs. 15.4%). Conclusion: Low vitamin D status (deficiency and insufficiency) was more common in clinic-visiting children than in health examinations, especially in schoolchildren and in the winter. The study implies the positive effects of vitamin D assessments included in child health checkups to optimize vitamin D status. [ABSTRACT FROM AUTHOR]

Background: Genome-wide association studies in Western countries indicate a considerable impact of variations in vitamin D binding protein (GC) genes on serum concentrations of 25-hydroxyvitamin D (25(OH)D). We aimed to investigate an association between rs2282679 polymorphism in GC and vitamin D deficiency. Methods: A cross-sectional study conducted in the framework of the Tehran Cardio-Metabolic Genetic Study (TCGS) cohort. A total of 1568 participants aged > 18 years were randomly selected, and their 25(OH) D concentration was measured. Vitamin D deficiency was assessed concerning rs2282679 by descriptive and multivariate analysis, odds ratio (OR), and 95% confidence intervals (95%CI) calculated. Since the interaction term between rs2282679 and recruitment season was significant, we performed regression analysis separately for individuals whose blood was taken in high sunny and those whose blood was drawn in the low sunny season. Results: The rs2282679 polymorphism was in Hardy-Weinberg equilibrium (P > 0.05) in the studied population. The serum concentration of 25(OH) D median was 15.0 ng/mL, and the prevalence of VDD was 27.8%. The presence of the G allele in rs2282679 increases the risk of VDD in additive (OR = 1.35, 95% CI: 1.06–1.73) and dominant (OR = 1.33, 95% CI: 1.06–1.68) genetic models. After separating participants based on the recruitment season, the unfavorable association was observed in the additive and dominant only in the low sunny season. Conclusion: The finding of the current study indicates that the GC rs2282679 SNP is associated with vitamin D deficiency. It seems that the impact of risk allele increased in the low sunny season when UV exposure has been declined. [ABSTRACT FROM AUTHOR]

Background: There are many studies on the relationship between vitamin D and coronavirus disease 2019 (COVID-19), while the results are matters of debate and the mechanisms remain unknown. The present study was performed to assess the impact of serum 25-hydroxyvitamin D [25(OH)D] levels on the severity of disease in hospitalized COVID-19 patients and identify potential mechanisms of 25(OH)D alterations. Methods: A total of 399 hospitalized COVID-19 patients were recruited from three centers between December 19, 2022, and February 1, 2023. Medical history, laboratory examination, and radiologic data were retrospectively collected. The patients were divided into four groups based on disease severity. Serum 25(OH)D levels in the patients were determined by the electrochemiluminescence method and cytokines were detected by flow cytometry. The relationship between serum 25(OH)D status and the severity of COVID-19, and the correlation between 25(OH)D levels and cytokines in COVID-19 patients were assessed. Results: Levels of 25(OH)D were significantly lower in the deceased group than in the other three groups (P < 0.05), and lower in the critical group than in the general group (P < 0.05). There were no significant differences in the 25(OH)D levels between the general and severe groups (P > 0.05). The levels of 25(OH)D (odds ratio = 0.986, 95% confidence interval: 0.973–0.998, P = 0.024) and IL-5 (odds ratio = 1.239, 95% confidence interval: 1.104–1.391, P = 0.04) were independent risk factors for the severity of COVID-19 disease upon admission. Serum 25(OH)D levels were able to predict the mortality of patients with COVID-19, and the predictive value was even higher when combined with IL-5 levels and eosinophil (Eos) count. Circulating 25(OH)D status correlated negatively with the expression of IL-5 (r=-0.262, P < 0.001) and was positively linked with CD8+ T cell counts (r=-0.121, P < 0.05) in patients with COVID-19. Conclusions: This study found that the serum 25(OH)D status combined with IL-5 levels and Eos counts could be identified as a predictive factor for recognizing the risk of COVID-19 mortality. The serum 25(OH)D status in COVID-19 patients correlated negatively with the expression of IL-5. The potential mechanism for this relationship is worth further exploration. [ABSTRACT FROM AUTHOR]

Background: Previous observational studies have shown associations between vitamin Ds and FGIDS[Including irritable bowel syndrome(IBS) and functional dyspepsia(FD)]. However, the association is controversial and the causality remains unknown. In this study, two-sample MR was cited to explore the causal effect on FGIDS caused by vitamin D level and serum 25-hydroxyvitamin D. Method: The GWASs of vitaminD and 25-hydroxyvitamin D, with 57–99 strongly related SNPs were all obtained from UK biobank. The GWASs of IBS and FD were obtained from FinnGen biobank with respectively 187,028 and 194,071 participants involved. Fixed-effect inverse variance weighted regression was used to evaluate causal estimates. Other statistical methods such as MR Egger, weighted median estimation, maximum likelihood estimation and penalty-weighted median estimation are also used to verify the accuracy of the main results. Results: Measuring by the IVW method, our research indicated that no causal relationship was detected between vitamin D intake and Functional gastrointestinal disorders [IVW, OR(vitamin D-IBS) = 0.909, 95% CI 0.789–1.053, p = 0.2017); OR(vitamin D-FD) = 1.0662, 95% CI 0.9182–1.2380, p = 0.4000]. As for serum 25-hydroxyvitamin D, no causal relationship was detected on FD(IVW, OR(25-hydroxyvitamin D-FD) = 0.9635, 95% CI 0.8039–1.1546, p = 0.6869). Nevertheless, a negative causal relationship was revealed between 25-hydroxyvitamin D and IBS(IVW, OR(25-hydroxyvitamin D-IBS) = 0.832, 95% CI 0.696–0.995, p = 0.0436). Sensitive analysis supported the main findings but did not suggest bias due to pleiotropy. Conclusions: Our Mendelian randomization analyses suggest a negative causal relationship between 25-hydroxyvitamin D and IBS. For each additional SD increase of genetically determined 25-hydroxyvitamin D levels, the risk of IBS decreased by 16.8%. [ABSTRACT FROM AUTHOR]

Background: This study was conducted to assess the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cardiovascular disease (CVD) mortality in older people with chronic kidney disease (CKD) in the United States. Methods: We identified 3230 CKD participants aged ≥ 60 years from the National Health and Nutrition Examination Survey (2001–2018). CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2. Mortality outcomes were determined by linkage to National Death Index (NDI) records through December 31, 2019. Restricted cubic spline based on Cox regression models were utilized to elucidate the nonlinear relationship between serum 25(OH)D concentrations and mortality in patients with CKD. Results: During median 74 months of follow-up, 1615 all-cause death and 580 CVD death were recorded. We found an L-shaped association between serum 25(OH)D concentrations and all-cause and CVD mortality, reaching a plateau at 90 nmol/L. Accordingly, per one-unit increment in natural log-transformed 25(OH)D was associated with a 32% and 33% reduced risk of all-cause mortality (hazard ratio [HR] 0.68; 95%CI, 0.56 to 0.83) and CV mortality (HR 0.69; 95%CI, 0.49 to 0.97) in participants with serum 25(OH)D < 90 nmol/L, but no considerable difference was observed in participants with serum 25(OH)D ≥ 90 nmol/L. Compared with those in the deficiency group (< 50 nmol/L), insufficient (50 to < 75 nmol/L) and sufficient group (≥ 75 nmol/L) were significantly associated with lower all-cause mortality (HR,0.83; 95%CI, 0.71 to 0.97 and HR, 0.75; 95%CI, 0.64 to 0.89) and CV mortality (HR,0.87; 95%CI, 0.68 to 1.10 and HR, 0.77; 95%CI, 0.59 to < 1.0), respectively. Conclusion: An L-shaped relationship between serum 25(OH)D levels with all-cause and CVD mortality was observed in elderly CKD patients in the United States. A 25(OH)D concentration of 90 nmol/L may be the target to reduce the risk of premature death. [ABSTRACT FROM AUTHOR]

Background: At present, there is no clinical study to elucidate the correlation between vitamin D deficiency and the incidence of diabetic foot osteomyelitis (DFO).This study aims to clarify levels of 25-hydroxyvitamin D [25(OH)VD] in peripheral blood and vitamin D receptor (VDR) expression in wound margin tissues (T-VDR) of patients with type 2 diabetes mellitus (T2DM) with diabetic foot ulcer (DFU) and DFO, and to determine its correlation with treatment outcomes of DFU and DFO, and and its value as a potential biomarker for the diagnosis of DFU and DFO. Methods: 156 T2DM patients with DFU (DFU group), 100 T2DM patients without DFU (T2DM group), and 100 healthy controls (NC group). The DFU group patients were subdivided into DFO (n = 80) and NDFO groups (n = 76). The level of serum 25(OH)VD was measured via chemiluminescence immunoassay, and T-VDR expression level was determined by quantitative real-time PCR. Results: The levels of serum 25(OH)VD in the DFU group were significantly lower than the T2DM group [(10.3 (5.8, 18.7) vs 15.7 (8.6, 24.6) ng/mL, P = 0.002)]. Similarly, the levels of serum 25(OH)VD and T-VDR expression in the DFO group were statistically lower than the NDFO group [9.2 (5.2, 20.5) vs 12.8 (6.9, 22.1) ng/mL, P = 0.006)], [1.96 (0.61, 3.97) vs 3.11 (1.36, 5.11), P = 0.004)], respectively. Furthermore, the levels of serum 25(OH)VD and T-VDR expression in DFU patients were positively correlated with the ulcer healing rate of foot ulcer after 8 weeks of treatment (P = 0.031, P = 0.016, respectively). Multivariate logistic regression analysis showed that low level of serum 25(OH)VD was an independent risk factor for DFU and DFO (ORDFU = 2.42, ORDFO = 3.05, P = 0.008, 0.001, respectively), and decreased T-VDR expression level was an independent risk factor for DFO (OR = 2.83, P = 0.004). Meanwhile, the ROC curve analysis indicated that the AUC of serum 25(OH)VD level for the diagnosis of DFU and DFO was 0.821 (95% CI, 0.754–0.886, P < 0.001) and 0.786 (95%CI, 0.643–0.867, P < 0.001), respectively. When establishing a diagnosis of DFO, the AUC of T-VDR expression level was 0.703 (95%CI: 0.618–0.853, P < 0.001). Conclusions: The levels of serum 25(OH)VD and T-VDR expression in DFU and DFO decreased. Serum 25(OH)VD and T-VDR are potentially valuable biomarkers for diagnosis and prognosis of DFU and DFO.. [ABSTRACT FROM AUTHOR]

To investigate the relationship between serum high-density lipoprotein (HDL-C) and spinal bone mineral density (BMD) under different serum 25-hydroxyvitamin D (25 (OH) D) levels in adults over 40 years old and to explore its mechanism. We include participants over the age of 40 with data on HDL-C, 25 (OH) D, spinal BMD, and other variables in the National Health and Nutrition Examination Survey 2007–2010 in the analysis. A weighted multiple linear regression model was used to evaluate the association between serum HDL-C and spinal BMD in different gender, ages, and serum 25 (OH) D levels. A total of 3599 subjects aged ≥ 40 years old were included in this study. Univariate analysis of the complete correction model showed a negative correlation between serum HDL-C and spinal BMD. In the two subgroups of serum 25 (OH) D, we found that the higher the serum HDL-C in the female with serum 25 (OH) D < 75 nmol/L aged 40–59 years old, the lower the total spinal BMD, and a similar relationship was found in the lumbar spine. However, no similar relationship was found in all populations with serum 25 (OH) D ≥ 75 nmol/L and males with serum 25 (OH) D < 75 nmol/L. These results suggest that among Americans over the age of 40, the increase in serum HDL-C is related to decreased BMD of spine only in women aged 40–59 years with vitamin D insufficiency or deficiency. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the association between sleep duration and bone mineral density (BMD) and determine whether vitamin D (VD) status influenced the association between sleep duration and BMD. Methods: National Health and Nutrition Examination Survey 2007–2014 participants aged ≥ 40 years were included in this study. BMD testing was conducted with dual-energy X-ray absorptiometry examinations. Moreover, all individuals were divided into four groups according to self-reported nocturnal sleep duration (7–8 h; 6 h; < 6 h; and > 8 h). In addition, the differences in BMD between the normal sleep duration group and other groups were calculated using multiple linear regression models. Results: Overall, the median age of the overall study population was 55.00 years old, with 46.97% of men distributed. Participants sleeping > 8 h/night had lower BMDs than those sleeping 7–8 h/night. Moreover, the association between unhealthy sleep duration (especially > 8 h/night) and low BMD was more pronounced in older individuals, men, postmenopausal women, and subjects with inadequate VD intakes (< 15.00 µg/day) or deficient/insufficient serum 25-hydroxyvitamin D (< 75.00 nmol/L). Conclusions: In conclusion, unhealthy sleep duration, especially long sleep duration, was associated with decreased BMD, particularly among individuals aged > 60 years, men, or postmenopausal women. Moreover, VD status might influence the association between sleep duration and BMD, especially in the context of inadequate VD intake or deficient/insufficient serum 25-hydroxyvitamin D levels. However, given the limitations of the present study, further investigation is warranted to confirm this association and to explore potential mechanisms. [ABSTRACT FROM AUTHOR]

Background: To investigate the correlation between N-terminal probrain natriuretic peptide (NT-proBNP), 25-hydroxyvitamin D (25-(OH) D), high-mobility group box 1(HMGB1), endogenous activin A (ACTA), blood glucose level, electrolyte levels and developmental quotient (DQ) scores of Hypoxic-ischemic encephalopathy (HIE). Methods: In this retrospective study, a total of 90 neonates diagnosed with HIE who were admitted to our hospital from January 2018 to June 2021 were retrospectively enrolled, and 40 healthy full-term neonates born in our hospital during the same period were randomly selected. Neonates with HIE and healthy conditions were set as the study group and control group, respectively. Neonates with HIE are divided into three subgroups, mild, moderate, and severe, based on the severity of HIE. The Gesell Developmental Scale (GDS) was used to assess neural development of neonates at 9 to 12 months postnatal. Biomarkers of peripheral venous blood were measured and collected in all neonates, including NT-proBNP, (25-(OH) D), HMGB1, ACTA, electrolyte levels and blood glucose levels. General demographic information and Apgar score were compared between the two groups. The differences between the two groups of biomarkers were compared and the correlation between these biomarkers and DQ scores was evaluated. Results: There was no significant difference in gestational age, maternal age, gender, way of birth, birth weight, gestational age and whether the mother was a primipara between the two groups (P>0.05). The 10 min Apgar score of the study group (5.87±0.36) was lower than that of the control group (9.37±0.32) with significant difference (P<0.05). The levels of NT-proBNP, HMGB1, and ACTA in the study group were higher than that in the control group (243.87±21.29 pmol/L vs. 116.98±22.19 pmol/L; 8.92±1.87 μg/L vs. 3.28±1.08 μg/L; 23.78±0.89 ng/ml vs. 2.98±0.38 ng/ml), while the levels of 25-(OH) D and electrolyte levels were lower than that in the control group (24.28±1.87 vs. 31.29±1.93; K+: 4.49±0.23 mmol/L vs. 4.73±0.21 mmol/L; Na+: 118.76±13.02 mmol/L vs. 134.28±12.29 mmol/L; Ca2+: 1.77±0.23 mmol/L vs. 2.35±0.26 mmol/L; Mg2+: 0.61±0.17 mmol/L vs. 0.91±0.17 mmol/L), with statistically significant differences (P<0.001). The levels of NT-probNP, HMGB1, ACTA and the incidence of hypoglycemia were the highest in the severe group, which were significantly higher than those in the moderate group and mild group (P<0.05). The levels of NT-probNP, HMGB1, ACTA and the incidence of hypoglycemia were the lowest in the mild group. The 25-(OH) D level, the incidence of hyperglycemia and electrolyte levels were the lowest in the severe group, which were significantly lower than those in the moderate and mild groups (all P<0.05). Meanwhile, the 25-(OH) D level, the incidence of hyperglycemia and electrolyte levels in the moderate group were lower than those in the mild group, and the differences were statistically significant (all P<0.05). The incidence of hyperglycemia in severe group (16 cases) was the lowest, significantly lower than that in moderate group (17 cases) and mild group (22 cases), and the difference was statistically significant (all P<0.05). The DQ scores of HIE neonates were negatively correlated with NT-proBNP, HMGB1, and ACTA (r=-0.671, -0.421, -0.518, all P< 0.001). The DQ scores was positively correlated with levels of 25-(OH) D and blood glucose level (r =0.621, 0.802, all P< 0.001). The DQ scores was also positively correlated with levels of potassium, sodium, calcium and magnesium (0.367, 0.782, 0.218, 0.678, all P<0.001). Conclusion: The NT-proBNP, HMGB1, ACTA, 25-(OH) D, blood glucose levels and electrolyte levels are correlated with the severity of HIE, and developmental quotient scores in neonates with HIE. These biomarkers are suggestive for assessing the prognosis of neonate with HIE. [ABSTRACT FROM AUTHOR]

Background: 25-hydroxyvitamin D [25(OH)D] deficiency in patients with Obstructive Sleep Apnea (OSA) has long been noted, but identifying the exact causal relationship remains hard. Investigation of the causality between 25(OH)D deficiency and OSA would help facilitate disease prevention.Methods: We conducted a two-sample bi-directional Mendelian randomization (MR) study. For forward analysis, 237 newly identified genetic variants are used as proxies for 25(OH)D to estimate the unconfounded effect on OSA among 16,761 OSA cases and 201,194 controls of European ancestry. Reverse analysis was performed to detect the causal impact of OSA on 25(OH)D levels. The inverse variance weighted (IVW) method was used as the primary analysis. Sensitivity analysis was performed to evaluate the robustness of our results. Multivariate MR analysis was conducted to evaluate the direct link between 25(OH)D and OSA after accounting for body mass index (BMI).Results: IVW indicated that OSA causally associated with a lower level of 25(OH)D ((β = -0.03, 95% CI = -0.06 ~ -0.007, P = 0.01). No evidence of the causal link from 25(OH)D to OSA was detected (OR = 0.99, 95% CI = 0.88 ~ 1.12, P = 0.85). Sensitivity analysis suggested the MR estimates were not biased. Multivariate MR analysis indicated the effect of OSA on 25(OH)D vanished upon accounting for BMI (β = -0.011, 95% CI = -0.028 ~ 0.007, P = 0.23).Conclusion: This MR study provided evidence that OSA was causally associated with a lower level of 25(OH)D, which might be driven by BMI. Obesity management should be enhanced in patients with OSA to prevent 25(OH)D deficiency. [ABSTRACT FROM AUTHOR]

Background: The relationship between vitamin D status and mortality in patients with osteoarthritis (OA) is unknown. This study investigated the associations of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among American adults with OA.Methods: This study included 2556 adults with OA from the National Health and Nutrition Examination Survey (2001-2014). Death outcomes were ascertained by linkage to National Death Index (NDI) records through 31 December 2015. Cox proportional hazards model and two-piecewise Cox proportional hazards model were used to elucidate the nonlinear relationship between serum 25(OH)D concentrations and mortality in OA patients, and stratified analyses were performed to identify patients with higher mortality risk.Results: During 16,606 person-years of follow-up, 438 all-cause deaths occurred, including 74 cardiovascular disease (CVD)-related and 78 cancer deaths. After multivariable adjustment, lower serum 25(OH)D levels were significantly and nonlinearly associated with higher risks of all-cause and CVD mortality among participants with OA. Furthermore, we discovered L-shaped associations between serum 25(OH)D levels and all-cause and CVD mortality, with mortality plateauing at 54.40 nmol/L for all-cause mortality and 27.70 nmol/L for CVD mortality. Compared to participants with 25(OH)D levels below the inflection points, those with higher levels had a 2% lower risk for all-cause mortality (hazard ratio [HR] 0.98, 95% confidence interval [CI] 0.96-0.99) and 17% lower risk for CVD mortality (HR 0.83, 95% CI 0.72-0.95).Conclusions: Nonlinear associations of serum 25(OH)D levels with all-cause and CVD mortality were observed in American patients with OA. The thresholds of 27.70 and 54.40 nmol/L for CVD and all-cause mortality, respectively, may represent intervention targets for lowering the risk of premature death and cardiovascular disease, but this needs to be confirmed in large clinical trials. [ABSTRACT FROM AUTHOR]

Background: Vitamin D insufficiency or deficiency is associated with an altered microbiota in older men. However, the relationship between the gut microbiota and 25-hydroxyvitamin D (25(OH)D) levels remains unknown in postmenopausal women. In this study, fecal microbiota profiles for 88 postmenopausal women in the high 25(OH)D (HVD) group (n = 44) and the low 25(OH)D (LVD) group (n = 44) were determined. An integrated 16S rRNA gene sequencing and liquid chromatography–mass spectrometry (LC–MS)-based metabolomics approach was applied to explore the association of serum 25(OH)D levels with the gut microbiota and fecal metabolic phenotype. Adjustments were made using several statistical models for potential confounding variables identified from the literature. Results: The results demonstrated that the community diversity estimated by the Observe, Chao1 and ACE indexes was significantly lower in the LVD group than in the HVD group. Additionally, two kinds of characteristic differences in the microflora were analyzed in the HVD group, and ten kinds of characteristic differences in the microflora were analyzed in the LVD group. We observed that some bacteria belonging to the genera Bifidobacterium, Bacillus, F0332 and Gemella, were enriched in the LVD group, as were other genera, including Lachnoclostridium, UC5_1_2E3, Ruminococcus_gnavus_group and un_f_Lachnospiraceae. Christensenellaceae, Eggerthellaceae and Cloacibacillus were enriched in the HVD group. The L-pyroglutamic acid, inosine, and L-homocysteic acid levels were higher in the HVD group and were negatively correlated with the 1,2-benzenedicarboxylic acid and cholic acid metabolic levels. Conclusions: These observations provide a better understanding of the relationships between serum 25(OH)D levels and the fecal microbiota and metabolites in postmenopausal women. [ABSTRACT FROM AUTHOR]

Background: Abnormal vitamin D is prevalent in critical care settings, but its association with prognosis remains unclear. The study aimed to investigate the prevalence and predictors of abnormal blood 25-hydroxyvitamin D (25(OH)D), as well as its association with prognosis in critically ill patients. Methods: Patients aged ≥ 18 years who were once admitted to the intensive care units (ICUs) of the Beth Israel Deaconess Medical Center between 2008 and 2019 with at least one measurement record of blood 25(OH)D were included as study population. Baseline characteristics associated with deficient or elevated blood 25(OH)D were investigated by univariable logistic regression analysis. The association between abnormal blood 25(OH)D and hospital mortality was examined by multivariable logistic regression analysis. Results: A total of 1091 patients were included. Deficient 25(OH)D (< 30 ng/mL) was found in 790 (72.41%) patients and 17 (1.56%) were with an elevated level (> 60 ng/mL). A younger age, male, comorbid liver disease, and dialysis were risk factors of deficient blood 25(OH)D, while comorbid myocardial infarction, dementia, and rheumatic disease were protective factors evaluated by univariable logistic regression. Being admitted to cardiac vascular ICU or coronary care unit were associated with increased risk of elevated blood 25(OH)D. Patients with elevated blood 25(OH)D showed non-significantly higher hospital mortality compared to those with normal or deficient blood 25(OH)D (35.29% versus 14.44% and 14.56%, P = 0.058). After adjusted for potential confounding factors, elevated blood 25(OH)D was associated with increased risk of hospital mortality [odds ratio (OR) 3.80, 95% confidence interval (CI) 1.22–11.82, P = 0.021] when compared to those with normal blood 25(OH)D, but there was no significant association between deficient blood 25(OH)D and hospital mortality (OR 1.12, 95% CI 0.74–1.72, P = 0.589). Conclusions: These findings suggest deficient blood 25(OH)D was rather common in critically ill patients, but was not an independent risk factor of hospital mortality, while elevated blood 25(OH)D was associated with worse prognosis. [ABSTRACT FROM AUTHOR]

Background: The study aim was to obtain epidemiological data on vitamin D levels for the pediatric population in Japan. We assessed the prevalence of vitamin D deficiency and insufficiency in 2-year-old Japanese children using data from a large ongoing birth cohort study.Methods: Data for analysis was obtained from the Japan Environment and Children's Study (JECS) and a Sub-Cohort Study (SCS) of JECS. We evaluated the children's serum 25(OH) D levels by 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles, and the rates of vitamin D deficiency or insufficiency. We also presented a weighted prevalence rate for vitamin D deficiency or insufficiency among all children in JECS.Results: After excluding children with missing 25(OH)D2 or 25(OH)D3 data, we analyzed 4655 remaining children, of whom 24.7% (95% CI, 23.5-26.0%) had vitamin D deficiency (< 20 ng/mL), and 51.3% (95% CI, 49.8-52.7%) were at risk of vitamin D insufficiency (20-30 ng/mL). The estimated prevalence of vitamin D deficiency and insufficiency among all children in JECS were 25.4% (95% CI, 24.1-26.7%) and 50.9% (95% CI, 49.4-52.4%). Vitamin D deficiency was found in 22.9% of boys and 26.5% of girls. Median serum 25(OH) D concentrations were lower among participants measured during winter and spring than among those measured in summer and autumn. The highest rate of vitamin D deficiency was observed in Hokkaido, the northernmost prefecture of Japan.Conclusion: We analyzed data on serum 25(OH) D levels from a birth cohort study and found that vitamin D deficiency and insufficiency are very common among 2-year-old Japanese children. Sex, season, and latitude affect serum 25(OH) D concentrations. [ABSTRACT FROM AUTHOR]

Background: Amongst the contributing factors of depression, vitamin D deficiency has increasingly drawn attention in recent years. This paper seeks to examine the association between serum vitamin D level and depression in patients with obesity. Methods: In this comparative observational study, serum 25-hydroxyvitamin D [25(OH)D] levels were compared between obese individuals with depression (n = 174) and those without depression considering the effect of potential confounders. Participants were selected from males and females aged 18 to 60 years old visiting the outpatient obesity clinic of Rasoul-e Akram hospital, Tehran, Iran. The diagnosis of depressive disorder was made based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria. Additional clinical and laboratory data were collected from hospital electronic records. Mann–Whitney U test (nonparametric), Student's t-test (parametric), and Chi-squared test were used to analyze the differences between the two groups. To examine age and gender differences in the relationship between vitamin D deficiency and depression, stratified analyses were conducted by age and gender groups. Results: The mean 25(OH) D levels were significantly different between depressed and non-depressed groups (20 ± 15 vs. 27 ± 13, P < 0.001). Vitamin D insufficiency/deficiency was detected in 78 and 67% of the depressed and non-depressed groups, respectively, which was significantly different (P = 0.03). The associations between depression and the serum 25(OH) D levels were observed regardless of gender and age. The overall average vitamin D levels were not significantly different between total males and females (22 ± 13 vs. 23 ± 14, P = 0.49). The average level of vitamin D was higher in the older age group (40–60 years) compared to younger participants (18–39 years) (26 ± 15 vs. 21 ± 13, P = 0.004). Conclusion: The present study provides additional evidence for the hypothesis that low vitamin D serum concentration is associated with depression in obese adults, and highlights the need for further research to determine whether this association is causal. [ABSTRACT FROM AUTHOR]

Background: Adequate levels of vitamin D are important for women of childbearing age as vitamin D helps maintain the pregnancy and ensures proper maternal and fetal bone metabolism and fetal skeletal development. However, vitamin D deficiency is a health problem prevalent in women of all ages, worldwide. This study aimed to determine the current status of serum vitamin D levels and the risk factors for vitamin D deficiency among South Korean nurses of childbearing age. Methods: Serum levels of 25-hydroxyvitamin D (25[OH]D) were measured in 1594 registered nurses aged 20 to 45 years who are participants in an ongoing prospective cohort study of the Korean Nurses' Health Study initiated in 2013. The participants completed surveys about demographic and occupational characteristics and physical and psychological health. We examined associations with vitamin D deficiency through multivariable logistic regression analysis. Results: The average blood 25(OH) D concentration of the participants was 12.92 ng/mL (4.0–63.4 ng/mL), while the prevalence of vitamin D deficiency (< 20 ng/mL) was 89% (1419/1594). Multivariable logistic regression showed that significant risk factors for vitamin D deficiency included month of sampling (there was a lower level of vitamin D deficiency in winter than in spring, summer, or fall), age (women in their 20s had a lower vitamin D level than those in their 30s and 40s), and stress symptoms. Vitamin D levels were not associated with body mass index, physical activity, and depressive symptoms. Conclusions: This study showed a high prevalence of vitamin D deficiency in Korean female nurses. Serum levels of vitamin D were associated with age and season. Vitamin D deficiency should be recognized as one of the primary health concerns among young women. More proactive actions, such as vitamin D supplements and food fortification, are needed to improve vitamin D deficiency in high-risk groups. [ABSTRACT FROM AUTHOR]

Objective: To establish the reference interval of serum 25-hydroxyvitamin D (25(OH)D) in apparently healthy children in Zigong, China, using an indirect method to provide a basis for proper clinical diagnosis and treatment. Methods : A total of 1851 apparently healthy children of the Children's Health Care Department in Zigong First People's Hospital between January 2016 and December 2020 were included in the study. The Kolmogorov–Smirnov test was used to analyze the data for normality, and the non-normally distributed data were transformed into approximately normal distribution by Blom's normal rank transformation, and the transformed data were excluded from outliers by the quartile spacing method, and the data were stratified and analyzed according to sex, age, and season. The data were stratified according to sex, age, and season, and the area between the 2.5% and 97.5% percentile points was used as the reference interval. Results: The serum 25(OH)D data were non-normally distributed. The data were normally distributed after Blom's normality rank transformation, and 92 cases of outliers were excluded from the transformed data according to the interquartile spacing method. The differences in serum 25(OH)D levels between sex were not statistically significant (P > 0.05), and there was no need to establish reference intervals based on sex. There was no statistically significant difference in serum 25-hydroxyvitamin D levels between winter and spring, and also no difference between summer and autumn (P > 0.05), and the levels were lower in winter-spring than in summer-autumn. Comparison between age groups showed that there was no statistically significant difference in serum 25(OH)D levels between the < 6 months group and the 6 ~ 11 months group, and between the 6 ~ 9 years group and the 10 ~ 14 years group (P > 0.05); serum 25(OH)D levels decreased with increasing age. There was an interactive effect of season and age group on 25(OH)D levels, and the corresponding reference intervals were established according to different seasons and age groups. In summer and autumn, the reference intervals of serum 25(OH)D for < 1 year, 1 ~ 2 years, 3 ~ 5 years, and 6 ~ 14 years were 39.86 ~ 151.43, 31.54 ~ 131.65, 22.05 ~ 103.75, and 15.36 ~ 85.53 ng/ml and 24.42 ~ 144.20, 31.54 ~ 131.65, 16.80 ~ 165.68, and 15.46 ~ 85.54 ng/ml in winter and spring, respectively. Conclusion: Reference intervals for serum 25(OH)D in children of different seasons and ages in Zigong, China, were established to provide a reference for clinical disease diagnosis, treatment, and prognosis determination. [ABSTRACT FROM AUTHOR]

Background: Periodontitis can lead to the destruction of periodontium and adversely influence the overall health, wellbeing, and quality of life. However, studies on the relationship between severe periodontitis and serum 25-hydroxyvitamin D [25(OH)D] are limited. This study is designed to explore the relationship between 25(OH)D and severe periodontitis. Methods: A cross-section study of 2928 participants enrolled from the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2014 was conducted. The periodontal examination was performed using a total oral periodontal examination program, and probe measurements were collected at six sites per tooth in NHANES. Severe periodontitis was characterized as: ≥ 2 interproximal sites with attachment loss (AL) ≥ 6 mm (not on the same tooth) and ≥ 1 interproximal site with probing depth (PD) ≥ 5 mm. Severe periodontitis and serum 25(OH)D were the dependent and independent variables, respectively. Univariate, multivariate, and subgroup analyses were performed to explore the relationship between severe periodontitis and serum 25(OH)D. Results: Among the 2928 participants, the average age of the population was 50 ± 13.71 years old, with 1425 (48.67%) males, 316 (10.79%) exhibited severe periodontitis. Serum 25(OH)D showed a significantly negative association with severe periodontitis after adjusting all variables (OR 0.75, 95% CI 0.63–0.89). In addition, severe periodontitis has a nonlinear relationship with serum 25(OH)D, whoes inflection point was 102 (nmol/L). On the left side of the inflection point (25(OH)D ≤ 102 nmol/L), the effect size was 0.98 and 95%CI was 0.98–0.99 (25(OH)D per 1 nmol/L increments). On the right side of the inflection point (25(OH)D > 102 nmol/L), the effect size was 0.99 and 95% CI was 0.98–1.01. The subgroup analysis showed pronounced changes in non-Hispanic white, alcohol consumption, diabetes, and health insurance. Conclusion: Serum 25 (OH) D in relation to severe periodontitis is nonlinear in our study.When serum 25 (OH) D is less than 102 nmol/L, serum 25 (OH) D is negatively associated with severe periodontitis. [ABSTRACT FROM AUTHOR]

We looked at existing recommendations and supporting evidence on the effectiveness of vitamin D supplementation in infancy for reducing vitamin D deficiency and for preventing rickets and infections. We also looked at optimal dose of vitamin D and the age until which vitamin D supplementation is beneficial.We conducted a literature search up to the 17th of July 2019 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendation when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported.A daily dose of 400 international units of vitamin D in infants has shown to be effective for improving bone health and preventing rickets. Evidence is more robust in groups of infants and children at risk. Vitamin D supplementation is well tolerated, and not associated with toxicity. Higher doses have not shown to add benefit while it could potentially cause toxic blood levels and hypercalcemia. Adequate levels of vitamin D might not be achieved with lower daily doses. Universal vitamin D supplementation starting shortly after birth, regardless of the mode of feeding and until 12 months of age, is strongly recommended. Beyond 12 months of age vitamin D supplementation is recommended only in groups of children at risk. [ABSTRACT FROM AUTHOR]

Background: Many international medical organizations recommend vitamin D supplementation for infants, especially exclusively breastfed infants. In Thailand, however, data regarding the vitamin D status in Thai infants are lacking. Such data would help to support physician decisions and guide medical practice.Methods: Full-term, exclusively breastfed infants were randomized into two groups at 2 months of age to continue exclusive breastfeeding either without vitamin D supplementation (control group, n = 44) or with vitamin D3 supplementation at 400 IU/day (intervention group, n = 43) until 6 months of age. At 6 months, the serum vitamin D (25OHD) of the infants and their mothers, serum bone marker, and infants' growth parameters were compared between the two groups.Results: The infants' serum 25OHD concentration was lower in the control group than intervention group (20.57 ± 12.66 vs. 46.01 ± 16.42 ng/mL, p < 0.01). More infants had vitamin D sufficiency (25OHD of > 20 ng/mL) in the intervention group than control group (93.0% vs. 43.2%, p < 0.01). There were no significant differences in the maternal 25OHD concentrations between the control and intervention groups (25.08 ± 7.75 vs. 23.75 ± 7.64 ng/mL, p = 0.42). Serum calcium, phosphorus, intact parathyroid hormone, alkaline phosphatase, and infants' growth parameters were comparable between the two groups. After adjustment for the confounding factors, 25OHD concentration in the intervention group was 25.66 ng/mL higher than the control group (95% confidence interval, 19.07-32.25; p < 0.001). Vitamin D supplement contributed to an 88.7% decrease in the prevalence of vitamin D insufficiency/deficiency (relative risk, 0.11; 95% confidence interval, 0.04-0.35; p < 0.01).Conclusions: Most full-term, exclusively breastfed Thai infants have serum vitamin D concentration below sufficiency level at 6 months of age. However, vitamin D supplementation (400 IU/day) improves their vitamin D status and prevents vitamin D deficiency.Trial Registration: The study was pre-registered in the Thai Clinical Trials Registry ( TCTR20190622001 ) on 22/06/2019. [ABSTRACT FROM AUTHOR]

Background: Vitamin D is an essential micronutrient for the overall health and well-being of individuals. For strong musculoskeletal and neurological development of human body, vitamin D levels during childhood and adolescence have key importance. This is the first national-level study that analyzes the deficiency and concentration of serum 25-Hydroxyvitamin D [25(OH)D)] among Indian children and adolescents with respect to various demographic and socioeconomic characteristics.Methods: Data of Comprehensive National Nutrition Survey (CNNS, 2016-18) was utilized for the present study. Vitamin D levels were assessed based on serum 25-hydroxyvitamin D concentration. Prevalence of vitamin D deficiency has been shown for the three age groups: 0-4 years (n = 12,764), 5-9 years (n = 13,482), 10-19 years (n = 13,065). Vitamin D deficiency was defined as: serum 25(OH)D < 12 ng/mL; and insufficiency as: 12 ng/ml ≤ 25(OH) < 20 ng/ml. 25(OH) D level higher than 20 ng/mL was accepted as adequate. Random slope multilevel logistic regression models were employed to assess the demographic and socioeconomic correlates of vitamin D deficiency.Results: Mean serum 25(OH)D concentration level was found to be 19.51 ± 8.76, 17.73 ± 7.91, and 17.07 ± 8.16 ng/ml in age group 0-4 years, 5-9 years and 10-19 years respectively. 49.12% of the children aged 0-4 years were having insufficient level of vitamin D. Prevalence of vitamin D deficiency was comparatively higher among female adolescents (76.16%), adolescents living in rural region (67.48), Sikh individuals (0-4 years: 76.28%; 5-9 years: 90.26%; 10-19 years: 89.56%), and adolescents coming from rich households. North-Indian individuals were having substantially higher odds of vitamin D deficiency in all the three age groups.Conclusion: The present study demonstrated that the prevalence of vitamin D deficiency is considerably high among children and adolescents of India. The study highlights high-risk group which require prompt policy interventions. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency has been associated with type 2 diabetes (T2D) and metabolic syndrome (MS) and its components. However, it is unclear whether a low concentration of vitamin D is the cause or consequence of these health conditions. Thus, this study aimed to evaluate the association of vitamin D concentrations and its genetic risk scores (GRSs) with MS and its component diseases, such as T2D, in middle-aged and elderly participants from rural eastern China.Methods: A subset of 2393 middle-aged and elderly individuals were selected from 70,458 participants of the Nantong Chronic Diseases Study of 2017-2018 in China. We used two 25-hydroxyvitamin D (25[OH]D) synthesis single-nucleotide polymorphisms (SNPs) (DHCR7-rs12785878 and CYP2R1-rs10741657) and two 25(OH) D metabolism SNPs (GC-rs2282679 and CYP24A1-rs6013897) for creating GRSs, which were used as instrumental variables to assess the effect of genetically lowered 25(OH) D concentrations on MS and T2D based on the Wald ratio. F statistics were used to validate that the four SNPs genetically determined 25(OH) D concentrations.Results: Compared to vitamin D sufficient individuals, individuals with vitamin D insufficiency had an odds ratio (OR [95% confidence interval {CI}]) of MS of 1.30 (1.06-1.61) and of T2D of 1.32 (1.08-1.64), individuals with vitamin D deficiency had an ORs (95% CI) of MS of 1.50 (1.24-1.79) and of T2D of 1.47 (1.12-1.80), and those with vitamin D severe deficiency had an ORs (95% CI) of MS of 1.52 (1.29-1.85) and of T2D of 1.54 (1.27-1.85). Mendelian randomization analysis showed a 25-nmol/L decrease in genetically instrumented serum 25(OH) D concentrations using the two synthesis SNPs (DHCR7 and CYP2R1 genes) associated with the risk of T2D and abnormal diastolic blood pressure (DBP) with ORs of 1.10 (95%CI: 1.02-1.45) for T2D and 1.14 (95%CI: 1.03-1.43) for DBP.Conclusions: This one sample Mendelian randomization analysis shows genetic evidence for a causal role of lower 25(OH) D concentrations in promoting of T2D and abnormal DBP in middle-aged and elderly participants from rural China. [ABSTRACT FROM AUTHOR]

Background: Children living in sub-Saharan Africa have a high burden of rickets and infectious diseases, conditions that are linked to vitamin D deficiency. However, data on the vitamin D status of young African children and its environmental and genetic predictors are limited. We aimed to examine the prevalence and predictors of vitamin D deficiency in young African children.Methods: We measured 25-hydroxyvitamin D (25(OH)D) and typed the single nucleotide polymorphisms, rs4588 and rs7041, in the GC gene encoding the vitamin D binding protein (DBP) in 4509 children aged 0-8 years living in Kenya, Uganda, Burkina Faso, The Gambia and South Africa. We evaluated associations between vitamin D status and country, age, sex, season, anthropometric indices, inflammation, malaria and DBP haplotypes in regression analyses.Results: Median age was 23.9 months (interquartile range [IQR] 12.3, 35.9). Prevalence of vitamin D deficiency using 25(OH)D cut-offs of < 30 nmol/L and < 50 nmol/L was 0.6% (95% CI 0.4, 0.9) and 7.8% (95% CI 7.0, 8.5), respectively. Overall median 25(OH)D level was 77.6 nmol/L (IQR 63.6, 94.2). 25(OH)D levels were lower in South Africa, in older children, during winter or the long rains, and in those with afebrile malaria, and higher in children with inflammation. 25(OH)D levels did not vary by stunting, wasting or underweight in adjusted regression models. The distribution of Gc variants was Gc1f 83.3%, Gc1s 8.5% and Gc2 8.2% overall and varied by country. Individuals carrying the Gc2 variant had lower median 25(OH)D levels (72.4 nmol/L (IQR 59.4, 86.5) than those carrying the Gc1f (77.3 nmol/L (IQR 63.5, 92.8)) or Gc1s (78.9 nmol/L (IQR 63.8, 95.5)) variants.Conclusions: Approximately 0.6% and 7.8% of young African children were vitamin D deficient as defined by 25(OH)D levels < 30 nmol/L and < 50 nmol/L, respectively. Latitude, age, season, and prevalence of inflammation and malaria should be considered in strategies to assess and manage vitamin D deficiency in young children living in Africa. [ABSTRACT FROM AUTHOR]

Background: Muscle and bone interactions might be associated with osteoporosis and sarcopenia. Urinary pentosidine and serum 25-hydroxyvitamin D (25(OH)D) might affect muscle and bone interactions. It is unclear whether these biomarkers are affected by age and sex or play a role in muscle and physical functions. We aimed to investigate the association between urinary pentosidine and serum 25(OH)D levels with muscle mass, muscle strength, and physical performance in community-dwelling adults.Methods: Two-hundred and fifty-four middle-aged and elderly adults were enrolled. There was no significant difference in age between 97 men (75.0 ± 8.9 years) and 157 women (73.6 ± 8.1 years). The skeletal muscle mass index (SMI), grip strength, and gait speed were assessed. The urinary pentosidine level was measured. We evaluated the association of urinary pentosidine and serum 25(OH)D levels with age and sex (student's t-test) and correlations between biomarker and each variable (Pearson's correlation coefficients). Multiple regression analysis was performed with grip strength and gait speed as dependent variables and with age, height, weight, body mass index (BMI), speed of sound (SOS), SMI, glycated hemoglobin (HbA1c), estimated glomerular filtration rate (eGFR), 25(OH)D, and pentosidine as independent variables using the stepwise method.Results: The urinary pentosidine level was negatively correlated with grip strength, gait speed, eGFR, and insulin-like growth factor-1 (IGF-1) in men and with SOS, grip strength, and gait speed in women. The serum 25(OH)D level was positively correlated with IGF-1 in women and grip strength in men. Grip strength was associated with age, height, and pentosidine in men and height and pentosidine in women. Gait speed was associated with age, BMI, and pentosidine in men and age, height, and pentosidine in women.Conclusion: Urinary pentosidine levels are significantly associated with grip strength and gait speed and may serve as a biomarker of muscle and bone interactions. [ABSTRACT FROM AUTHOR]

Background: Hypovitaminosis D in pregnancy is associated with adverse health outcomes in mothers, newborns and infants. This study assessed the levels of 25-hydroxyvitamin D [25(OH)D] in normotensive pregnancies and in preeclampsia, evaluated the association between vitamin D deficiency and preeclampsia risk; and determined the foeto-maternal outcome in preeclamptic women with vitamin D deficiency.Methods: This case-control study was conducted among pregnant women who visited the Comboni Hospital, in Ghana from January 2017 to May 2018 for antenatal care. A total of 180 pregnant women comprising 88 preeclamptic women (PE) and 92 healthy normotensive pregnant women (NP) were recruited. Socio-demographic, clinical and obstetric data were obtained using validated questionnaires. Blood pressure and anthropometrics were measured, and blood samples were collected for the estimation of 25- hydroxyvitamin D [25(OH)D] using enzyme-linked immunosorbent assay technique. Lipids (total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol) were also estimated.Results: A total of 81.7% of the study participants had vitamin D deficiency. Of these, 88.6% of the women with PE had vitamin D deficiency compared to 75.0% in the NP. Vitamin D levels were significantly reduced in the PE women compared to the normotensive pregnant women (p = 0.001). A higher proportion of the preeclamptic women who were vitamin D deficient had preterm delivery (p < 0:0001) and delivered low birth weight infants (p < 0:0001), and infants with IUGR (p < 0:0001) compared to the control group (p < 0:0001). Pregnant women with PE presented with significant dyslipidemia, evidenced by significantly elevated TC (p = 0.008), LDL (p < 0.0001), triglycerides (p = 0.017) and a significantly reduced HDL (p = 0.001) as compared to NP. In the preeclamptic women, serum 25(OH) D showed an inverse, but not significant association with TC (β = - 0.043, p = 0.722, TG (β = - 0.144, p = 0.210) and LDL (β = - 0.076, p = 0.524) and a positive, but not significant association with HDL (β = 0.171, p = 0.156).Conclusion: The prevalence of vitamin D deficiency is high in both normotensive pregnancies and pregnancies complicated by preeclampsia but amplified in preeclampsia. Higher proportion of pregnant women with hypovitaminosis D had preterm babies and delivered low birth weight neonates. Additional studies are needed to explore the potential benefits and optimal dosing of vitamin D use in pregnancy, especially in sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

Background: Hypovitaminosis D can be observed in most fragility hip fracture patients. However, measurement of 25-hydroxyvitamin D (25(OH)D) level is costly and may not be available in some centers. Without the baseline serum 25(OH)D level, the appropriate dose of vitamin D supplementation is not known. The aim of this study was to evaluate the effectiveness and safety of vitamin D supplementation in fragility hip fracture patients compared between high- and low-dose vitamin D supplementation.Methods: A total of 140 patients diagnosed with fragility hip fracture were randomly allocated to either the high-dose (60,000 IU/week) or low-dose (20,000 IU/week) vitamin D2 supplementation group for 12 weeks. The number of patients who achieved optimal vitamin D level (serum 25(OH)D > 30 ng/mL), the proportion of patients who developed hypercalcemia, and the functional outcome were compared between groups.Results: Of the 140 patients who were enrolled, 21 patients were lost to follow-up during the study period. The remaining 119 patients (58 and 61 in the high- and low-dose groups, respectively) were included in the final analysis. The high-dose group had a higher rate of serum 25(OH)D restoration to optimal level than the low-dose group (82.8% vs 52.5%, respectively; p < 0.001). Approximately 3.4 and 1.6% of patients in the high- and low-dose groups, respectively, had mild transient hypercalcemia, but none developed moderate, severe, or symptomatic hypercalcemia. There were no differences in functional outcome scores between groups.Conclusions: In treatment settings where baseline serum 25(OH)D level can't be evaluated in older adults with fragility hip fracture, we recommend high-dose vitamin D2 of approximately 60,000 IU/week for 12 weeks, with subsequent switch to a maintenance dose. This regimen effectively restored serum vitamin D to an optimal level in 82.8% of patients without causing symptomatic hypercalcemia.Trial Registration: The protocol of this study was retrospectively registered in the Thai Clinical Trials Registry database no. TCTR20180302007 on 20 February 2018. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency and related metabolic bone diseases in pet rabbits have been intermittently debated. In human research, the parathyroid hormone concentration in relation to the 25-hydroxyvitamin D concentration is used to determine vitamin D deficiency. Thus, this study aimed to identify the breakpoint in the 25-hydroxyvitamin D concentration indicating a significant change in the parathyroid hormone concentration in 139 pet rabbits. An enzyme immunoassay kit was used for 25-hydroxyvitamin D analysis and the intact parathyroid hormone (PTH 1–84) immunoradiometric assay kit for parathyroid hormone analysis. The mid-tibial cortical bone density was measured using peripheral quantitative computed tomography. A segmented linear regression analysis was performed, with the 25-hydroxyvitamin D concentration as the independent variable, and parathyroid hormone, ionised calcium, total calcium, inorganic phosphorus concentrations and the mid-tibial cortical density as the dependent variables. Results: The breakpoint for the parathyroid hormone concentration occurred at a 25(OH)D concentration of 17 ng/mL, whereas the cortical bone density breakpoint occurred at a 25-hydroxyvitamin D concentration of 19 ng/mL. No breakpoints were found for ionised calcium, total calcium or phosphorus. Conclusions: These results suggest that a serum 25-hydroxyvitamin D concentration of 17 ng/mL serves as the threshold for vitamin D deficiency in rabbits. Nearly one-third of the rabbits had a serum 25-hydroxyvitamin D concentration below this threshold. Concerns persist regarding the high prevalence of vitamin D deficiency in pet rabbits and the possible health consequences caused by a chronic vitamin D deficiency, including the risk for metabolic bone diseases. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency has been often observed in obese persons. One of the mechanisms suggested for low vitamin D status in obesity was decreased bioavailability of vitamin D (VD) due to sequestration in adipose tissue. However, only few studies have investigated this mechanism via quantifying vitamin D levels from tissues from the obese. Methods: Six-wk-old C57BL/6 mice were fed 10 or 45% kcal fat (CON or HFD) diets containing 50, 1000 or 25,000 IU vitamin D3/kg diet (LVd, CVd or HVd) for 13 wks. Serum 25-hydroxyvitamin D (25(OH)D) levels were determined by radioimmunoassay and liver and adipose tissue cholecalciferol (VD3) and 25-hydrocholecalciferol (25(OH)D3) levels were measured by LC-MS/MS. mRNA levels of jejunal Mttp, Cd36, Sr-b1, Npc1l1, and Abca1 and liver and adipose tissue 25-hydroxylases (Cyp2r1 and Cyp27a1) were determined by real-time PCR. Results: Serum 25(OH)D levels were affected by dietary vitamin D content but differential effects were observed between HFD and CON groups. When vitamin D intake was at a supplementary level, the HFD-HVd group had lower serum 25(OH)D levels than the CON-HVd group, while there was no significant difference between the HFD and CON groups fed LVd or CVd. Total amount of VD3 in liver and adipose tissue were significantly higher in HFD-HVd group compared with the CON-HVd group. However, no difference in total amount of tissue VD3 was observed between the CON and HFD groups fed CVd. In jejunum, mRNA levels of Mttp and Abca1 were significantly higher in HFD groups than CON groups. There was no difference in mRNA levels of liver 25-hydroxylases by both dietary fat amount and vitamin D content. Conclusion: A significant amount of VD3 seemed to be stored in the liver and adipose tissue when dietary vitamin D is at a supplementation level; thus excess body adiposity could contribute to relatively low serum 25(OH)D level when vitamin D was supplemented. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency has been related to the risk of sepsis. However, previous studies showed inconsistent results regarding the association between serum 25-hydroxyvitamin D (25 (OH) D) and mortality risk in septic patients. We aimed to evaluate the relationship between serum 25 (OH) D at admission and mortality risk in adult patients in a meta-analysis.Methods: Follow-up studies that provided data of multivariate adjusted relative risk (RR) between serum 25 (OH) D and mortality risk in septic patients were retrieved via systematic search of PubMed and Embase databases. A random effect model was used to pool the results.Results: Eight studies with 1736 patients were included. Results of overall meta-analysis showed that lower 25 (OH) D at admission was independently associated with increased risk or mortality (adjusted RR: 1.93, p < 0.001; I2 = 63%) in patients with sepsis. Exploring subgroup association showed that patients with severe vitamin D deficiency (25 (OH) D < 10 ng/ml) was significantly associated with higher mortality risk (adjusted RR: 1.92, p < 0.001), but the associations were not significant for vitamin D insufficiency (25 (OH) D 20~30 ng/ml) or deficiency (25 (OH) D 10~20 ng/ml). Further analyses showed that the association between lower serum 25 (OH) D and higher mortality risk were consistent in studies applied different diagnostic criteria for sepsis (systemic inflammatory response syndrome, Sepsis-2.0, or Sepsis-3.0), short-term (within 1 month) and long-term studies (3~12 months), and in prospective and retrospective studies.Conclusions: Severe vitamin D deficiency may be independently associated with increased mortality in adult patients with sepsis. Large-scale prospective studies are needed to validate our findings. [ABSTRACT FROM AUTHOR]

Objective: We aimed to describe the 25-hydroxyvitamin D (25(OH)D) status of southern Chinese individuals by a high-accuracy liquid chromatography tandem mass spectrometry (LC-MS/MS) method which can trace to reference measurement procedure. Materials and methods: From January 2018 to June 2019, a total of 4775 southern Chinese individuals were evaluated in our study. The serum levels of parathyroid hormone (PTH) were detected simultaneously in 162 cases. 25(OH)D was determined by LC-MS/MS, and PTH was detected using routine automated analysers. The distribution of the concentration, prevalence and seasonal variability of 25(OH)D in males and females of different age groups were studied. Results: The mean 25(OH)D concentration in our study was 32.57 ng/mL (4.20–101.40 ng/mL). The global 25(OH)D concentration in males was higher than that in females of different age group. The prevalence of vitamin D deficiency (< 20 ng/mL) in females (16.65%) was higher than that in males (6.83%). The prevalence of vitamin D deficiency (< 20 ng/mL) was most common in winter (22.98% of all women and 15.49% of all men). 25(OH)D concentrations were higher in those from whom blood samples were collected in summer and autumn than in winter and spring. 25(OH)D2 was detected in 672 serum samples (14.07%). In addition, there was a negative correlation between the concentrations of 25(OH)D and serum PTH (r = − 0.149, P < 0.05). Conclusion: Our study demonstrated that the average serum 25(OH)D concentration in southern Chinese individuals was higher than that in other Chinese cohorts by a high-accuracy LC-MS/MS method. The global 25(OH)D concentration in males was higher than that in females of different ages, and the prevalence of vitamin D deficiency in females was higher than that in males. Seasonal change was an important aspect of 25(OH)D concentration in young and middle-aged people but became less relevant for that in older subjects. 25(OH)D2 detection was of minor practical significance in our study. In addition, we also found that there was a negative correlation between the serum levels of 25(OH)D and PTH in southern Chinese individuals. [ABSTRACT FROM AUTHOR]

Background: Serum 25-hydroxyvitamin D (25 (OH) D) levels are associated with various pathologic ocular conditions. Few studies have assessed 25 (OH) D concentrations in non-serum specimens, and none to date has assessed 25 (OH) D concentrations in human aqueous humor and their association with ocular diseases. This study investigated the possible correlations between 25 (OH) D concentrations in aqueous humor and serum and whether vitamin D concentrations in aqueous humor were associated with cataract.Methods: This study prospectively enrolled 136 patients, including 87 with senile cataract and 49 with diabetic cataract, who underwent cataract surgery from January to November 2017. 25 (OH) D was measured in aqueous humor and serum specimens collected from all patients, and their correlation was analyzed statistically. Clinical and laboratory data, including the results of ophthalmologic examinations, were compared in the two groups of cataract patients.Results: No correlation was observed between 25 (OH) D concentrations in aqueous humor and serum (P = 0.381). 25 (OH) D concentrations in aqueous humor were significantly higher in patients with diabetic than senile cataract (P = 0.006). Multivariate logistic regression analysis showed that the adjusted odds ratio for diabetic cataract for the highest compared with the lowest quartile of 25 (OH) D concentration in aqueous humor was 4.36 ng/ml (95% confidence interval [CI]: 1.33-14.34 ng/ml; P = 0.015). Multivariate linear regression analysis showed that 25(OH) D concentration in aqueous humor was 2.68 ng/ml (95% CI: 0.34-5.01 ng/ml; P = 0.025) higher in patients with diabetic than senile cataract.Conclusions: 25(OH) D concentrations in aqueous humor and serum did not correlate with each other. Higher 25(OH) D level in aqueous humor was associated with diabetic cataract. These findings suggest that studies of vitamin D levels in patients with ocular conditions should include measurements of vitamin D levels in aqueous humor. [ABSTRACT FROM AUTHOR]

Background: Previous studies have investigated the vitamin D status in patients with chronic hepatitis B virus (HBV) infection and its relationship with HBV replication, the results however were inconsistent. The present meta-analysis was carried out to compare the vitamin D levels between patients with chronic hepatitis B (CHB) and healthy controls, and to determine whether vitamin D levels were correlated with HBV viral loads significantly.Methods: A systematic search was conducted via PubMed, Web of Science, EMBASE and the Cochrane Library to identify eligible studies until September 28, 2017. We calculated pooled mean difference (MD) and 95% confidence intervals (CI) to quantitatively estimate the difference of vitamin D levels between CHB patients and controls. In addition, correlation between serum vitamin D levels and HBV viral loads was defined by summary correlation coefficient (r value) and the corresponding 95% CI.Results: A total of 7 studies involving 814 CHB patients and 696 healthy controls were included. A significantly decreased vitamin D levels was found in CHB patients compared with healthy controls: pooled MD (95% CI) was - 2.03 ng/mL (- 2.60, - 1.46). Latitude-stratified subgroup analysis indicated this difference was more obvious in low latitude areas, with a bigger pooled MD (95% CI) of - 2.72 ng/mL (- 4.57, - 0.87). In addition, we observed an inverse correlation between serum vitamin D levels and HBV viral loads: pooled r (95% CI) was - 0.41(- 0.54, - 0.27).Conclusions: Our results showed that vitamin D levels were lower in CHB patients than that of healthy controls and inversely correlated with HBV viral loads, although future comprehensive studies are needed to clarify the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Objective: Vitamin D deficiency is common among older adults and has been linked to muscle weakness. Vitamin D supplementation has been proposed as a strategy to improve muscle function in older adults. The aim of this study was to investigate the effect of calcifediol (25-hydroxycholecalciferol) on whole genome gene expression in skeletal muscle of vitamin D deficient frail older adults.Methods: A double-blind placebo-controlled trial was conducted in vitamin D deficient frail older adults (aged above 65), characterized by blood 25-hydroxycholecalciferol concentrations between 20 and 50 nmol/L. Subjects were randomized across the placebo group and the calcifediol group (10 μg per day). Muscle biopsies were obtained before and after 6 months of calcifediol (n = 10) or placebo (n = 12) supplementation and subjected to whole genome gene expression profiling using Affymetrix HuGene 2.1ST arrays.Results: Expression of the vitamin D receptor gene was virtually undetectable in human skeletal muscle biopsies, with Ct values exceeding 30. Blood 25-hydroxycholecalciferol levels were significantly higher after calcifediol supplementation (87.3 ± 20.6 nmol/L) than after placebo (43.8 ± 14.1 nmol/L). No significant difference between treatment groups was observed on strength outcomes. The whole transcriptome effects of calcifediol and placebo were very weak, as indicated by the fact that correcting for multiple testing using false discovery rate did not yield any differentially expressed genes using any reasonable cut-offs (all q-values ~ 1). P-values were uniformly distributed across all genes, suggesting that low p-values are likely to be false positives. Partial least squares-discriminant analysis and principle component analysis was unable to separate treatment groups.Conclusion: Calcifediol supplementation did not significantly affect the skeletal muscle transcriptome in frail older adults. Our findings indicate that vitamin D supplementation has no effects on skeletal muscle gene expression, suggesting that skeletal muscle may not be a direct target of vitamin D in older adults.Trial Registration: This study was registered at clinicaltrials.gov as NCT02349282 on January 28, 2015. [ABSTRACT FROM AUTHOR]

We would like to comment on the recently published article titled: "Circulating Vitamin D levels status and clinical prognostic indices in COVID-19 patients" by Ricci et al. The authors grouped the patients into two groups according to the vitamin D levels measured at the time of admission into the hospital and reported that lower vitamin D levels are associated with elevated D-dimer and IL-6 levels, low CD4/CD8 ratio and compromised clinical findings with elevated LIPI and SOFA scores. However, review of recent literature shows this association to be debatable. The 25-hydroxyvitamin D levels in the initial phase of critical illness have been reported to drop rapidly and hence consideration of the time of measurement from symptom onset would have enhanced the clinical relevance of these findings. Inferred association between vitamin D levels and disease severity based on SOFA score in COVID-19 patients, needs to be further explored in the light of the recent literature which casts doubt on using SOFA score at admission to predict mortality in COVID-19. [ABSTRACT FROM AUTHOR]

Background: Vitamin D deficiency and frailty are common with aging. Previous studies examining vitamin D status and frailty have produced mixed results, and in particular, the shape of the association has not been well established. We examined the association between 25-hydroxyvitamin D (25OHD) serum levels and frailty by performing a systematic review and dose-response meta-analysis.Methods: We searched the PubMed, EMBASE and Cochrane Library databases of Elsevier through February 2017. Cross-sectional and cohort studies that reported adjusted risk ratios with 95% confidence intervals (CI) for frailty with ≥3 categories of 25OHD serum levels were selected. Data extraction was performed independently by two authors. The reported risk estimates for 25OHD categories were recalculated, employing a comprehensive trend estimation from summarized dose-response data.Results: The pooled risk estimate of frailty syndrome per 25 nmol/L increment in serum 25OHD concentration was 0.88 (95% CI = 0.82-0.95, I2 = 86.8%) in the 6 cross-sectional studies and 0.89 (95% CI = 0.85-0.94, I2 = 0.0%) in the 4 prospective cohort studies. Based on the Akaike information criteria (AIC), a linear model was selected (AIC for the nonlinear model: - 5.4, AIC for the linear model: - 6.8 in the prospective cohort studies; AIC for the linear model: - 13.6, AIC for the nonlinear model: - 1.77 in the cross-sectional studies).Conclusions: This dose-response meta-analysis indicates that serum 25OHD levels are significantly and directly associated with the risk of frailty. Further studies should address the underlying mechanisms to explain this relationship and to determine whether vitamin D supplementation is effective for preventing frailty syndrome. [ABSTRACT FROM AUTHOR]

Background: Recent studies have shown a relationship between vitamin D status and growth hormone (GH) and insulin-like growth factor 1 (IGF1). The objective of this study was to assess vitamin D status in children with GH deficiency due to pituitary stalk interruption syndrome (PSIS) and to investigate the relationship between 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25 (OH) 2D) serum levels and patient characteristics.Methods: A retrospective single-center study of 25OHD and 1,25(OH)2D serum concentrations in 50 children with PSIS at the initial evaluation before treatment.Results: Mean concentrations of 33.2 ± 18.0 ng/mL for 25OHD and 74.5 ± 40.7 ng/L for 1,25(OH)2D were measured. Additionally, 25OHD concentrations were significantly higher in boys than in girls (p = 0.04) and lower in the cold season than in the sunny season (p = 0.03). Significant positive correlations were observed between the GH peak and serum 1,25 (OH) 2D concentrations (Rho = 0.35; p = 0.015) and the 1,25(OH)2D/25OHD ratio (Rho = 0.29; p < 0.05). No correlation was found for other characteristics, including IGF1.Conclusions: Vitamin D status in children with hypothalamic-pituitary deficiency due to PSIS was similar to that reported in national and European studies in healthy children. The positive significant correlations between the GH peak and the 1,25 (OH)2D concentration as well as with the 1,25 (OH)2D/25OHD ratio suggest that even in these patients who had severely impaired GH secretion and low IGF1 levels, an interplay between the GH/IGF1 axis and the vitamin D system still exists. [ABSTRACT FROM AUTHOR]