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Background: The potential effects of dietary oxalate (Ox) intake on cardio-renal function have remained unestablished. We evaluated the effect of usual Ox intake and its interaction with dietary calcium (Ca) on incident hypertension (HTN) and chronic kidney disease (CKD). Methods: Adult men and women, free of HTN and CKD at baseline (2006–2008), were recruited. Dietary intakes were assessed using a validated food frequency questionnaire, and the outcomes were documented up to 2014–2017. Multivariate Cox proportional hazard regression models were used to estimate the development of HTN and CKD in relation to Ox intakes. Repeated-measures generalized estimating equation (GEE) linear regression models were used to assess possible effect of Ox-intake on the estimated glomerular filtration rate (eGFR) and blood pressure levels over eight years. Results: Dietary Ox intakes were positively associated with incident CKD (HR = 2.59, 95% CI = 1.46–4.64) and HTN (HR = 1.79, 95% CI = 1.05–3.04). Compared to high-Ca consumers, subjects who had lower Ca intakes (< 990 vs. 1580 mg/d) had a higher incidence of CKD and HTN (HR = 2.43, 95% CI = 1.06–5.55, and HR = 1.72, 95% CI = 0.76–3.78). Participants with higher intakes of Ox (> 220 vs. < 150 mg/d) had lower eGFR values (75.3, 95% CI = 75.0–76.5 vs. 77.3, 95% CI = 76.6–78.1 mL/min/1.73m2, Ptime×group = 0.004) and higher SBP levels (112, 95% CI = 111–113 vs. 109, 95% CI = 108–110 mmHg, Ptime×group = 0.007) overtime. Conclusion: Higher dietary Ox intake may increase the risk of HTN and CKD. The relation between dietary Ox and risk of HTN and CKD seems to be varied by Ca intake, and subjects with lower Ca intakes may be more burdened by excessive amounts of dietary Ox. [ABSTRACT FROM AUTHOR]

Background: Hypovitaminosis D is common in Asian Indians and its functional significance is currently under investigation. Previous studies have reported on the effect of low serum 25(OH)D levels (<50 nmol L−1) on bone mineral density and serum parathyroid hormone values. The present study assessed the effect of chronic hypovitaminosis D in Asian Indians on intestinal calcium absorption and its change after cholecalciferol supplementation. Methods: Subjects included 29 healthy volunteers [mean (SD) age, 28.4 ± 6.4 years] with low serum 25(OH)D levels on screening. Intestinal calcium absorption was assessed by the ‘calcium load test’ with 1 g of oral elemental calcium. Subjects were put on a calcium restricted diet 1 week prior to the test. The calcium load test was repeated in 26 of them after 8 weeks of supplementation with oral cholecalciferol (60 000 IU week−1). Results: The mean urinary calcium/creatinine ratio of the study subjects was 0.027 ± 0.023 mg mg−1 under fasting conditions and increased to 0.035 ± 0.032 mg mg−1 after calcium loading (delta change = 29.6%, P = 0.33). After 8 weeks of cholecalciferol supplementation, the mean serum 25(OH)D increased from 18.9 ± 11.9 to 84.4 ± 34.9 nmol L−1 ( P < 0.0001). Concomitantly, the mean urinary calcium/creatinine ratio of the study subjects increased from 0.030 ± 0.024 mg mg−1 under fasting conditions to 0.059 ± 0.045 mg mg−1 after calcium loading (delta change = 96.6%, P = 0.008). Conclusions: The results obtained in the present study show that chronic hypovitaminosis D in Asian Indians has functional relevance in terms of its effect on intestinal calcium absorption, which improves with cholecalciferol supplementation. These findings support the need for improving the vitamin D status of Asian Indians through dietary supplementation and exposure to sunshine. [ABSTRACT FROM AUTHOR]

Treatment of osteoporosis has advanced dramatically during the past decade, with more therapeutic options than ever now available. Large-scale randomized placebo-controlled trials have documented the efficacy of a number of agents in reducing vertebral and non-vertebral fractures. Anti-resorptive agents (hormone replacement therapy, selective estrogen-receptor modulators, calcitonin and bisphosphonates) and bone-forming anabolic agents (parathyroid horomone and strontium ranelate) act via different mechanisms to reduce fractures and improve bone strength. In view of the high prevalence of calcium and vitamin D insufficiency in Asia, calcium and vitamin D supplementation remains a fundamental part of any treatment regimen, especially among the elderly. Given the high cost of these agents, a global assessment of the fracture risk of the patient is essential to determine the need for pharmacological treatment versus life-style modification and dietary supplementation in the management of postmenopausal osteoporosis in Asia. [ABSTRACT FROM AUTHOR]