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There is still controversy about optimal dietary iodine intake as the Universal Salt Iodization policy enforcement in China. A modified iodine balance study was thus conducted to explore the suitable iodine intake in Chinese adult males using the iodine overflow hypothesis. In this study, thirty-eight apparently healthy males (19·1 (sd 0·6) years) were recruited and provided with designed diets. After the 14-d iodine depletion, daily iodine intake gradually increased in the 30-d iodine supplementation, consisting of six stages and each of 5 d. All foods and excreta (urine, faeces) were collected to examine daily iodine intake, iodine excretion and the changes of iodine increment in relation to those values at stage 1. The dose–response associations of iodine intake increment with excretion increment were fitted by the mixed effects models, as well as with retention increment. Daily iodine intake and excretion were 16·3 and 54·3 μg/d at stage 1, and iodine intake increment increased from 11·2 μg/d at stage 2 to 118·0 μg/d at stage 6, while excretion increment elevated from 21·5 to 95·0 μg/d. A zero iodine balance was dynamically achieved as 48·0 μg/d of iodine intake. The estimated average requirement and recommended nutrient intake were severally 48·0 and 67·2 μg/d, which could be corresponded to a daily iodine intake of 0·74 and 1·04 μg/kg per d. The results of our study indicate that roughly half of current iodine intakes recommendation could be enough in Chinese adult males, which would be beneficial for the revision of dietary reference intakes.

Lead (Pb) pollution is a global public health problem and adversely affects children health across a wide range of exposure levels. This study was conducted to evaluate the blood Pb levels (BLLs) of Chinese urban children aged 6−11 years and to describe the temporal variations from the China Nutrition and Health Survey (CNHS) in 2002 and 2012. A total of 2182 (1036 vs. 1146) Chinese urban children were selected in the CNHS 2002 and the CNHS 2012 using the multistage stratified cluster random and probability proportional to size sampling method. The BLLs of urban children were determined using inductively coupled plasma mass spectrometer (ICP-MS), whilst the prevalence of BLLs >50 µg/L and >100 µg/L were calculated, as well as the reference values (RV95s: the upper limit of 95% confidence interval of 95th percentile). From the CNHS 2002 to the CNHS 2021, the median BLLs of Chinese urban children had obviously changed from 67.4 µg/L to 36.9 µg/L, and the RV95s of BLLs had also descrended from 149.1 µg/L to 107.9 µg/L. In addition, the prevalence of BLLs with >50 µg/L and >100 µg/L had markedly decreased from 74.0% and 18.2% in the CNHS 2002 to 28.4% and 5.2% in the CNHS 2021. In conclusion, the BLLs of Chinese urban children had been definitely improved in the past 10 years. However, the findings of our study suggested that it is imperative to implement the monitoring and evaluating and to continue control Pb exposure.

Background Knowledge of the physiologic requirement for iron, the core index for the formulation of a dietary reference intake (DRI), is of great importance for the health of a pregnant woman and her fetus, and can help a mother accurately plan her iron supplementation. However, direct measurements of the physiologic requirement for iron during pregnancy are still lacking. Method Eleven women of reproductive age from Hebei Province, China, who planned to become pregnant in the near future, were enrolled between January and March 2015 and included in the final analysis. Subjects participated in a 2-week metabolic trial in which they consumed 50 mg of the stable isotope 58Fe, and were then followed for ~ 2 years. The abundance of 58Fe and the total iron concentration in the circulation were measured using Multi-collector Inductively-Coupled Plasma Mass Spectrometry and Atomic Absorption Spectroscopy, respectively. The physiologic requirement for iron during pregnancy was then calculated by the formula derived from our previously published work. Results The mean physiologic requirement for iron in the 11 subjects, across their entire pregnancies, was 3.05 mg.d− 1 in total and 44.0 μg.kg− 1.d− 1 after adjustment for body mass. The physiologic requirements for iron in the first, second, and third trimesters were 2.04 mg.d− 1, 3.26 mg.d− 1, and 4.13 mg.d− 1, respectively. When adjusted for body mass, the physiologic requirements for iron in different trimesters were 32.3 μg.kg− 1.d− 1, 46.9 μg.kg− 1.d− 1, and 55.7 μg.kg− 1.d− 1, respectively. Conclusion We preliminarily explored the physiologic requirement for iron in pregnant women. The data demonstrated that pregnant women needed about twice iron than non-pregnant women. This research may be helpful for the design of future studies and the modification of iron DRIs. Trial registration ChiCTR, ChiCTR-OCH-14004302. Registered 14 February 2014, http://www.chictr.org.cn/showproj.aspx?proj=5267

Background Appropriate iodine intake for adults is essential to reduce the prevalence of thyroid diseases, but there is little research data on iodine requirement of Chinese population. This study aimed to explore the iodine requirement of young adults to maintain a healthy status based on ‘overflow theory’. Methods Iodine-balance experiment has been performed in this project. We conducted an 18-day study consisted of a 6-day acclimation period and 3 consecutive experimental stages in 37 Chinese healthy young adults (23 female and 14 male). Each stage was consumed for 4 days. Strictly-controlled low-iodine intake diets were provided for adults in the first period, an egg or 125mL milk was added in the second and third period, respectively. The dietary samples, 24-h urine specimens and faeces of volunteers were collected daily for assessment of iodine intake and excretion in volunteers. Results Mean values of iodine intake (22.7±3.6, 35.1±3.7, and 52.2±3.8μg/d), excretion (64.7±13.9, 62.3±12.6, and 94.3±14.5μg/d) and iodine balance (-35.2±19.5, -21.0±19.8, and -33.5±26.9μg/d) were significantly different among three periods for male (PP < 0.001 for all). No significant difference was observed among the 3 periods for female in the iodine balance (-30.5±9.3, -25.9±7.3, and -27.6±12.1μg/d). The linear regression equation of iodine excretion on iodine intake was Y=0.979X+37.04 (male) and Y=0.895X+31.48 (female). Compared with stage 2, iodine excretion increments in stage 3 had exceeded the iodine intake increment for men. The ratio of increment was 1.675 for male when the average iodine intake was 52.2μg/d in stage 3. When the iodine excretion increment equaled to the iodine intake increment, the daily iodine intake of men was 47.0μg. Conclusion We have evaluated the iodine requirement of young adults in southern China based on overflow theory. Our results indicate the lower limit of iodine requirement for Chinese young men is 47.0μg/d. The trial was registered at www.chictr.org.cn as ChiCTR1800014877.

Additional file 2: Table S2. Estimation of Maternal Weight Gain during Pregnancy.

Additional file 1: Table S1. The Circulation Rate of Non-pregnant Women.

Optimal vitamin D (vitD) status is beneficial for both pregnant women and their newborns. The aim of this study was to evaluate the vitamin D status of Chinese pregnant women in the latest China Nutrition and Health Surveillance (CNHS) 2015–2017, analyze the risk factors of vitamin D deficiency (VDD), and compare them with those in CNHS 2010–2012. Serum 25 hydroxyvitamin D (25(OH)D) was measured by ELISA method. City type, district, latitude, location, age, vitamin D supplements intake, education, marital status, annual family income, etc., were recorded. The median 25(OH)D concentration was 13.02 (10.17–17.01) ng/mL in 2015–2017, and 15.48 (11.89–20.09) ng/mL in 2010–2012. The vitamin D sufficient rate was only 12.57% in 2015–2017, comparing to 25.17% in 2010–2012. The risk factors of vitamin D inadequacy (25(OH)D &lt, 20 ng/mL) in 2015–2017 were not exactly consistent with that in 2010–2012. The risk factors included season of spring (p &lt, 0.0001) and winter (p &lt, 0.001), subtropical (p &lt, 0.001), median (p &lt, 0.0001) and warm temperate zones (p &lt, 0.0001), the western (p = 0.027) and the central areas (p = 0.041), while vitD supplements intake (p = 0.021) was a protective factor in pregnant women. In conclusion, vitD inadequacy is very common among Chinese pregnant women. We encourage pregnant women to take more effective sunlight and proper vitD supplements, especially for those from the subtropical, warm and medium temperate zones, the western and the central, and in the seasons of spring and winter.

In the present work, we evaluated the three generation reproductive toxicity of the genetically modified rice with insectresistant cry1Ac and sck genes. 120 Sprague-Dawley (SD) rats were divided into three groups which were fed with genetically modified rice diet (GM group), parental control rice diet (PR group) and AIN-93 control diet (both used as negative control) respectively. Bodyweight, food consumption, reproductive data, hematological parameters, serum chemistry, relative organ weights and histopathology for each generation were examined respectively. All the hematology and serum chemistry parameters, organ/body weight indicators were within the normal range or no change to the adverse direction was observed, although several differences in hematology and serum chemistry parameters (WBC, BUN, LDH of male rat, PLT, PCT, MPV of female rats), reproductive data (rate of morphologically abnormal sperm) were observed between GM rice group and two control groups. No macroscopic or histological adverse effects were found or considered as treatment-related, either. Overall, the three generation study of genetically modified rice with cry1Ac and sck genes at a high level showed no unintended adverse effects on rats's reproductive system.

This study assessed the bioavailability and biological incorporation of nonheme iron from staple food diets in healthy young urban Chinese women and determined the relevant effects of typical regional patterns of staple foods in South and North China.Twenty-two young urban Chinese women aged 20-23 years were enrolled and randomly allocated to two groups, with rice (rice group) and steamed buns (steamed buns group) as the staple food, respectively. Each participant received three meals daily containing approximately 3.25 mg of stable 57FeSO4 for 2 consecutive days, along with daily intravenous injection of approximately 2.0 mg of 58FeSO4. Nonheme iron absorption and infused iron incorporation rates were assayed.In all participants, the rice group, and the buns group, nonheme iron intake was 7.2±1.6, 5.9±0.6, and 8.4±1.2 mg, respectively; mean 57FeSO4 absorption rate was 22.2%±9.6%, 22.2%±10.6%, and 22.2%±8.9%, respectively; and the mean infused 58FeSO4 incorporation rate was 91.6%±8.2%, 93%±7.3%, and 90%±9.1%, respectively. No substantial differences existed in the nonheme iron intakes and the 57FeSO4 absorption and 58FeSO4 incorporation rates between the rice and buns groups (all p0.05).The bioavailability and incorporation rates of nonheme iron from representative comprehensive Chinese diets in healthy young urban Chinese women were evaluated. Our results can facilitate the establishment of dietary reference intake for iron in Chinese women.

Accurately assessing energy expenditure (EE) of people with different body weight is essential to facilitate weight management. The aim of this study was to measure basal energy expenditure (BEE), resting energy expenditure (REE) and to explore the true 1 MET value for young Chinese adults with different body weight.A total of 251 young Chinese adults were divided into three groups: the normal weight group, the overweight group and the obese group. Their BEE, REE and 1 MET values were measured by Cortex Metamax 3B (MM3B). Multiple linear regressions and correlation analysis were used to examine factors that influence EE in Chinese population.The mean measured BEE and REE of young Chinese adults with normal weight, overweight and obesity was 1429, 1609, 1778 kcal/day and 1522, 1712, 1885 kcal/day, respectively. The EE per kilogram body weight decreased with the increasing body weight. The mean oxygen consumption in the three group was 3.78, 3.47, 3.21 mL/kg/min respectively. There was no significant difference in BEE and REE after adjustment for fat-free mass (FFM). The significant influencing factors were body mass index (BMI) and sex in BEE, FFM and BMI in REE in Chinese population.BEE and REE were significantly different for different body weights while these differences disappeared after adjustment for FFM, and people with different body weights may have different 1 MET values. Further studies should be conducted to obtain more accurate daily energy requirement and 1MET value for specific Chinese populations.

Background Iron nutrition is important for the health of women of reproductive age, and defining the physiologic requirement for iron can help them accurately plan the iron intake. However, research on the physiologic requirement for iron in women is insufficient worldwide. This study aimed to further improve the methodology and get more precise data for the physiological requirements for iron in women of reproductive age on the basis of our previous study. Method Sixty-one women of reproductive age who had not been pregnant before and during the whole study were included from Hebei province, China in 2015. Each subject participated in a 2-week metabolic trial with consuming 50 mg of the stable isotope 58Fe, and were then followed for ~ 800 days. The abundance of 58Fe and the total iron concentration in the circulation were measured using multi-collector inductively-coupled plasma mass spectrometry and atomic absorption spectroscopy. The physiologic requirement for iron in women of reproductive age was then calculated. Results The average iron circulation rate was 80.4%, and the steady period started from about 1 year. The average physiological requirement for iron of 21 subjects obtained by formula calculation was 1.55 mg/d and 23.63 μg.kg− 1.d− 1 after adjustment for body mass, and that of 33 subjects obtained by linear regression was 1.29 mg/d, 20.98 μg.kg− 1.d− 1 after adjustment for body mass. The results by two methods showed no significant difference. The EAR and RNI calculated from this results was 11–13 mg/d and 15–18 mg/d, respectively, both of which were slightly lower than the recommended value in Chinese Dietary Reference Intake (2013). Conclusion The physiological requirements for iron in women of reproductive age were in accordance with other studies, while the EAR and RNI calculated from which were slightly lower than Chinese present recommended value. Trial registration ChiCTR, ChiCTR-OCH-14004302. Registered 14 February 2014, http://www.chictr.org.cn/enindex.aspx Electronic supplementary material The online version of this article (10.1186/s12986-019-0384-1) contains supplementary material, which is available to authorized users.

Summary Background Few studies have used nationally representative data to describe dietary trends and the related cardiometabolic mortality burden in China. Thus, we aimed to characterise the trends in disease-related dietary factors as well as their associated disease burden among Chinese adults from 1982 to 2012. Methods For this cross-sectional population-based study, we analysed a nationally representative sample of 204 802 adults aged 20 years or older, using data from the 1982, 1992, 2002, and 2010–12 China National Nutrition Surveys (CNNS). We did a comparative risk assessment, in which the effects of suboptimal intakes of 12 dietary factors, individually and collectively, on cardiometabolic mortality were estimated by calculating the population attributable fraction (PAF) to estimate the proportional reduction in cardiometabolic deaths that would occur if exposure to each dietary risk factor was reduced to an alternative optimal level. Findings The overall PAF of mortality from cardiovascular disease and type 2 diabetes that was associated with suboptimal dietary quality was 62·2% in 1982, 57·9% in 1992, 56·2% in 2002, and 51·0% in 2010–12, which accounted for 21·6% of total mortality in China in 1982, 16·6% in 1992, 17·6% in 2002, and 20·8% in 2010–12. The estimated number of cardiometabolic deaths associated with suboptimal dietary intakes was 1·07 million in 1982, 0·93 million in 1992, 1·18 million in 2002, and 1·51 million in 2010–12. Of all 12 dietary factors examined, high sodium intake (17·3%), low fruit consumption (11·5%), and low marine omega-3 fatty acids (9·7%) were associated with the largest numbers of estimated cardiometabolic deaths in 2010–12. Interpretation We observed an improvement in several dietary factors in China in the past few decades. However, current intakes of these dietary factors remain suboptimal. Poor diet quality is estimated to be associated with a substantial proportion of deaths from heart disease, stroke, and type 2 diabetes in China. Funding Ministry of Health, China, and Ministry of Science and Technology, China.

This study was conducted to examine the possible association between vitamin A status and overnutrition in Chinese urban children and adolescents. Weight, height and serum retinol were assessed in total 3457 children (7–9.9 years of age) and adolescents (10–17 years of age), using urban region data from the China National Nutrition and Health Survey 2010–2013 (CHNNS2010-2013) which is a nationally representative cross-sectional study. Prevalence of low serum concentration of retinol was 26.8% and 12.24% for overweight. Retinol inadequacy was significantly higher in children (32.13%) than in adolescents (24.48%). The average of retinol was significantly higher in overnutrified 42.32 μg/dL versus non-overnutrified 41.05 μg/dL (p = 0.00) children and adolescents. Overnutrified children and adolescents presented a greater chance of an increase in serum concentration of retinol (odds ratio 1.34, 95% confidence interval 1.10–1.63, and 1.48, 95% confidence interval (1.26–1.74) when compared with non-overnutrified children. An important correspondence between vitamin A deficiency and overnutrition was found. Non-overnutrified children and adolescents may have a greater chance of presenting low concentrations of retinol. Future public health strategies focused on the overnutrified population and vitamin A supplements should consider the effect of retinol on urban children and adolescents in China.

ObjectiveTo evaluate vitamin D deficiency prevalence and risk factors among pregnant Chinese women.DesignA descriptive cross-sectional analysis.SettingChina National Nutrition and Health Survey (CNNHS) 2010–2013.SubjectsA total of 1985 healthy pregnant women participated. Possible predictors of vitamin D deficiency were evaluated via multiple logistic regression analyses.ResultsThe median serum 25-hydroxyvitamin D level was 15·5 (interquartile range 11·9–20·0, range 3·0–51·5) ng/ml, with 74·9 (95 % CI 73·0, 76·7) % of participants being vitamin D deficient (25-hydroxyvitamin D P=0·016), lack of vitamin D supplement use (P=0·021) and low ambient UVB level (PP=0·012) and low ambient UVB level (PP=0·050), later gestational age (P=0·035), higher pre-pregnancy BMI (P=0·019), low ambient UVB level (PP=0·007).ConclusionsVitamin D deficiency is prevalent among pregnant Chinese women. Residing in areas with low ambient UVB levels increases the risk of vitamin D deficiency, especially for women experiencing advanced stages of gestation, for younger pregnant women and for women of Hui ethnicity; therefore, vitamin D supplementation and sensible sun exposure should be encouraged, especially in the winter months. Further studies must determine optimal vitamin D intake and sun exposure levels for maintaining sufficient vitamin D levels in pregnant Chinese women.

Vitamin D plays a critical role in calcium and phosphate metabolism and helps maintain skeletal integrity in childhood, yet vitamin D status in Chinese children and adolescents is not well documented. The aim of this study was to assess the vitamin D status and analyze the risk factors for vitamin D deficiency in Chinese children and adolescents aged 6–17 years. Serum 25 hydroxyvitamin D (25(OH)D) was measured with a radioimmunoassay kit in 15,000 children and adolescent participants in the Chinese national nutrition and health survey (CNNHS) 2010–2012. Age, gender, region type, ethnicity, outdoor time, and vitamin D supplementation were recorded in unified design questionnaires. The season was recorded by the date of blood taken; location was divided into north and south by China′s Qinling Mountains and Huaihe River; and ambient ultraviolet B (UVB) radiation level was classified according to the corresponding dose of each participant living area from National Aeronautics and Space Administration data. 14,473 participants from the cross-sectional study of CNNHS 2010–2012 were included in this study. The median serum 25(OH)D concentration was 48.2 (35.4–63.4) nmol/L, and the concentration for males was 50.0 (36.5–65.7) nmol/L, which was statistically higher than that of females (46.7 (34.4–60.9) nmol/L) (P < 0.001). The general prevalence of vitamin D deficiency was 53.2%; 50.0% for males and 56.5% for females at the cut-off 50 nmol/L. According to the results of the log-binomial regression analysis, vitamin D deficiency in Chinese children and adolescents was specifically related to female gender (P < 0.0001), to ages 12–14 years (P < 0.0001) and 15–17 years (P < 0.0001), living in large cities (P < 0.0001) or ordinary rural areas (P < 0.0001), low ambient UVB levels (P < 0.0001) and medium ambient UVB levels (P < 0.0001), spring (P < 0.0001), autumn (P < 0.0001) and winter seasons (P < 0.0001). The data showed that vitamin D deficiency was very common among children and adolescents aged 6–17 years in China. Effective sun exposure should be encouraged in both genders aged 6–17 years, dietary vitamin D and vitamin D supplements are also recommended, especially in the seasons of spring and winter.

Background Vitamin D inadequacy is common among the elderly, especially within the Asian population. The vitamin D status among healthy adults in the elderly Chinese population was evaluated. Methods A total of 6014 healthy adults aged 60 years or older (2948 men, 3066 women) participated in this descriptive cross-sectional analysis. Possible predictors of vitamin D inadequacy were evaluated via multiple logistic regression analyses. Results The median serum 25-hydroxyvitamin D (25(OH)D) levels were 61.0 nmol/l (interquartile range (IQR) 44.3–80.6, range 5.1–154.5) for men and 53.7 nmol/l (IQR 38.8–71.0, range 6.0–190.0) for women, with 34.1% (95% confidence interval (CI) 32.4–35.8) of men and 44.0% (95% CI 42.2–45.8) of women presenting vitamin D inadequacy (25(OH)D

The development of reference values of trace elements is recognized as a fundamental prerequisite for the assessment of trace element nutritional status and health risks. In this study, a total of 1400 pregnant women aged 27.0 ± 4.5 years were randomly selected from the China Nutrition and Health Survey 2010-2012 (CNHS 2010-2012). The concentrations of 14 serum trace elements were determined by high-resolution inductively coupled plasma mass spectrometry. Reference values were calculated covering the central 95% reference intervals (P2.5-P97.5) after excluding outliers by Dixon's test. The overall reference values of serum trace elements were 131.5 (55.8-265.0 μg/dL for iron (Fe), 195.5 (107.0-362.4) μg/dL for copper (Cu), 74.0 (51.8-111.3) μg/dL for zinc (Zn), 22.3 (14.0-62.0) μg/dL for rubidium (Rb), 72.2 (39.9-111.6) μg/L for selenium (Se), 45.9 (23.8-104.3) μg/L for strontium (Sr), 1.8 (1.2-3.6) μg/L for molybdenum (Mo), 2.4 (1.2-8.4) μg/L for manganese (Mn), 1.9 (0.6-9.0) ng/L for lead (Pb), 1.1 (0.3-5.6) ng/L for arsenic (As), 835.6 (219.8-4287.7) ng/L for chromium (Cr), 337.9 (57.0-1130.0) ng/L for cobalt (Co), 193.2 (23.6-2323.1) ng/L for vanadium (V), and 133.7 (72.1-595.1) ng/L for cadmium (Cd). Furthermore, some significant differences in serum trace element reference values were observed between different groupings of age intervals, residences, anthropometric status, and duration of pregnancy. We found that serum Fe, Zn, and Se concentrations significantly decreased, whereas serum Cu, Sr, and Co concentrations elevated progressively compared with reference values of 14 serum trace elements in pregnant Chinese women. The reference values of serum trace elements established could play a key role in the following nutritional status and health risk assessment.

In this study, we assessed the hemoglobin levels and anemia status of Chinese children and adolescents from the Chinese National Nutrition and Health Survey (CNNHS) in 2010–2012 and analyzed the factors associated with anemia. The hemoglobin concentration and prevalence of anemia for children and adolescents aged 6–17 years from both CNNHS 2010–2012 and CNNHS 2002 were analyzed. Multi-variable logistic regression analysis was used to assess the factors associated with anemia. The mean hemoglobin concentration increased among Chinese children and adolescents, from 135.2 ± 13.9g/L in CNNHS 2002 to 141.2 ± 15.8 g/L in CNNHS 2010–2012, with the prevalence of anemia decreasing from 12.6% to 6.6% (p&lt, 0.0001). Anemia was specifically related to girls (p &lt, 0.0001), children aged 6–8 years (p = 0.0175), 12–14 years (p = 0.0007), and 15–17 years (p &lt, ordinary rural areas (p = 0.0009) and poor rural areas (p &lt, spring (p &lt, 0.0001), autumn (p &lt, 0.0001), and winter (p &lt, underweight individuals (p &lt, and an annual average income per capita of less than 20,000 RMB (p &lt, 0.0001).The prevalence of anemia in Chinese children and adolescents has improved significantly in comparison to 10 years prior, however, it remains a public health problem in this population. Further research is required to understand the determinants of iron status, which could then lead to strategies to alleviate iron deficiency for Chinese children and adolescents, especially for girls, those living in rural areas, underweight individuals, and those with a low family income.

Anemia is a public health issue for developing countries, especially for women of childbearing age. The aim of this study was to assess the anemia status and analyze the risk factors for anemia in Chinese childbearing women aged 18&ndash, 49 years. Hemoglobin concentration was measured by the HiCN method in the Fifth Chinese National Nutrition and Health Survey (CNNHS) in 2010&ndash, 2012. Age, region type, ethnicity, bodyweight, height, education, season and smoke habit were recorded in unified questionnaires. Latitude was divided by China&rsquo, s Qinling Mountains and Huaihe River. Childbearing women (28,289) from the CNNHS 2010&ndash, 2012 were included in this study. The median hemoglobin concentration was 136.2(126.6&ndash, 145.0) g/L, and it was significantly higher than in CNNHS 2002 (132.5 (122.3&ndash, 141.6) g/L). The prevalence of anemia was 15.0%, and it was significantly lower than 10 years ago. The logistic regression analysis showed anemia in Chinese childbearing women was specifically related to 30&ndash, 39 age group (P = 0.004), in spring (P &lt, 0.0001) or in winter (P = 0.006), small and medium-sized cities (P = 0.044) and middle school education level (P = 0.027). The results showed that anemia status among childbearing women was greatly improved over 10 years since 2002, but it was still more severe than the rest of the populations. The nutrition propaganda and education is recommended for childbearing women to help them to improve the nutritional status on their own.

To assess the distribution of serum ferritin, serum soluble transferrin receptor and body iron among girls and women by age and anaemia.Serum ferritin, serum soluble transferrin receptor and high sensitive C-reactive protein of 1625 and 1372 women in general and anaemic were measured in the National Health and Nutrition Survey commenced in 2010.The distributions of serum ferritin, serum soluble transferrin receptor and body iron for 6-11-y, 12-17-y, 18-44-y, 45-59-y and=60-y subgroups were significantly different. Both in population-representative women and those anaemic, the iron status of 18-44-y women was the lowest and that of 12-17-y girls the second lowest. The iron status of anaemic women was lower than that in representative women at ages 12-17 y, 18-44 y, 45-59 y and=60 y.Iron status in women of different ages and anaemic had different distributions, but consistently lower than that of population-representative women. The observed iron status of Chinese urban women supports program planning for iron nutrition promotion in women. Iron status information is also needed for men and to understand the pathogenesis which may be related to intake or loss.背景与目的：评估不同年龄和贫血状况女孩和成年女性的血清铁蛋白、血清转 铁蛋白受体和铁储量的分布情况。方法与研究设计：2010 年中国居民营养与健 康状况监测中，对1625 名普通女性和1372 名贫血女性分别测定其血清铁蛋 白、血清转铁蛋白受体和高敏C 反应蛋白浓度。结果：6-11、12-17、18-44、 45-59 和=60 岁不同年龄组女性之间血清铁蛋白、血清转铁蛋白受体和铁储量的 分布显著不同。在普通女性组和贫血女性组中，18-44 岁年龄组的女性铁营养状 况均为最差，其次为12-17 岁年龄组。在12-17、18-44、45-59 和=60 岁年龄组 中，贫血女性的铁营养状况显著低于普通女性组。结论：不同年龄组及贫血状 况女性的铁营养状况分布不同，贫血组女性的铁营养状况较普通女性组差。本 研究观察到的中国大城市女性铁营养状况的数据，支持开展针对女性的铁营养 改善的项目规划，也需要调查男性铁营养状况，并探究可能与铁摄入或损失的 发病机制。.

Vitamin A deficiency is recognized as a major public-health nutrition issue in the developing countries. Limited hospital sources and sample sizes are available in most of the existing studies associated with healthy school-age children. The aim of this study was to compare vitamin A status of 6- to 13-year-old healthy children in China between 2002 and 2012. According to China National Nutrition and Health Survey 2002 (CHNNS2002) and CHNNS2010-2013, we choose 6- to 13-year-old children as the research object. We measure the serum retinol concentrations of the children using high performance liquid chromatography (HPLC). The children were divided into two groups: 6- to 9-year-old and 10- to 13-year-old. The areas were divided into urban and rural area. Total number of the children (6- to 13-year old) was 8170 in 2002 survey, and it was 6016 in 2012 survey. In 2012, the vitamin A level of the children was higher than that in 2002 (t = 39.26, p = 0.000). The level of vitamin A in 10- to 13-year-old group was higher than that in 6- to 9-year-old group across areas and genders between 2002 and 2012. There was no difference on the incidence of vitamin A deficiency in all the children between 2002 and 2012, but in 2012 the incidence of vitamin A deficiency in the urban children was higher than that in 2002 (x 2 = 45.456,p = 0.000). The incidence of vitamin A deficiency in 10- to 13-year-old group was lower than that in 10- to 13-year-old group across areas and genders between 2002 and 2012. In 2012, the incidence of marginal vitamin A deficiency in the children was lower than that in 2002 (x 2 = 861.604, p = 0.000). Similar phenomena were also found in across area groups. The incidence of marginal vitamin A deficiency in 10- to 13-year-old group was lower than that in 6- to 9-year-old group across areas and genders between 2002 and 2012. There was no difference in vitamin A status of the children across the area, gender and age groups between 2002 and 2012. Vitamin A nutritional status of the children in 2012 has been significantly improved compared with that in 2002. However, vitamin A deficiency was still a moderate public health problem in Chinese children, especially in younger school-age children. Consequently, controlling the incidence of vitamin a deficiency is imperative for promoting Chinese children’s health.

Objective The effect of dietary restriction, intense exercise and menstrual dysfunction on bone mineral density remains controversial. The aim of this study was to assess the skeletal health status and relationship between bone mineral density and nutrient intake, menstrual status, estrogen level and other factos in Chinese adolescent dancers. Methods Sixty dancers and 77 healthy controls underwent measurements of bone density, body composition, and estrogen level. Nutrient intake, menstrual status and physical activity were assessed with questionnaires. The correlation between these factors were analyzed. Results The dancers under study had a significantly lean body mass index (18.3±1.4 kg/m2 vs. 21.7±3.1 kg/m2), lower percentage of body fat (0.25±0.05 vs. 0.34±0.04) and later age at menarche (14.0±0.9 y vs. 13.0±1.3 y), and the estrogen level, daily calorie and fat intake in them were also lower than in the controls. All the dancers undertook intensive physical activity every day and up to 69% of them suffered from irregular menarche. Yet they had relatively high BMD and BMC of the total body and legs than the controls after adjusting for BMI and age. Site-specific BMD was positively correlated to BMI, body composition and training hours per week and negatively correlated to the age at menarche and menstrual frequency. Conclusions The relatively high BMD and BMC of the dancers at the total body and legs were probably caused by high levels of weight-bearing physical activity. To ameliorate disordered eating, especially low energy intake might be helpful to prevent the Triad and to improve the bone health in adolescent dancers.

To investigate the association between adiponectin and metabolic syndrome (MetS) and related diseases in older adults from major cities of China.A total of 2 049 adults at the age of 60-96 years from 18 major cities of China were enrolled in the study. Plasma adiponectin and insulin concentrations were measured. Insulin resistance was assessed by homeostasis model assessment of insulin resistance (HOMA-IR). The definitions proposed by International Diabetes Federation (IDF) and American Heart Association/National Heart, Lung, and Blood Institute (AHA/NLHBI) were used to identify MetS.The adiponectin concentration increased with the advance of age and was higher in women than in men. The sex specific adiponectin concentration was inversely correlated with body mass index (BMI), waist circumference, diastolic blood pressure, triglycerides, glucose and fasting blood insulin, and positively correlated with HDL-C (P0.001). The adiponectin concentration decreased with increasing MetS components. Compared with the 4th sex-specific adiponectin quartile, the odds ratio (OR) for prevalent MetS-IDF and MetS-AHA/NLHBI in subjects of the 1st quartile group was 3.25 (95% CI: 2.24, 4.71) and 3.21 (95% CI: 2.26, 4.55), respectively. The association was independent of age, sex, life-style factors, medication, family history of chronic diseases, BMI, and HOMA-IR. The OR for MetS was much higher than those of MetS components and its related diseases.Adiponectin is strongly associated with MetS independent of insulin resistance and obesity in older adults from major cities in China. The adiponectin concentration is a useful predictor for the risk of MetS.

Objective To investigate plasma leptin concentrations in adolescent female dancers and to determine whether leptin has some effects on their bone mineral density (BMD) and bone turnover markers. Methods Sixty dancers aged 15-17 years and 77 healthy controls were enrolled in the study. Bone mineral density (BMD) and body composition were detected by dual energy X-ray absorptiometry. Serum leptin concentrations were measured by radioimmunoassay (RIA). Two bone turnover markers, bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase(TRACP), were determined by ELISA. Results The dancers had a lower fat mass and a lower leptin level than the controls, while they had a relatively higher BMD of the total body and legs after adjustment for BMI and age. The levels of bone resorption and formation of markers were higher in the dancers than in the controls. Leptin was positively correlated with BMI, body weight, fat mass, and percentage of body fat. In dancers, Leptin was positively correlated with the BMD of the total body and the left leg. However, after adjustment for BMI, no correlation of serum leptin concentrations with BMD values was found in either dancers or controls. Nor correlation was found between leptin and bone turnover markers after adjustment for BMI. Conclusion The leptin profile is different between the controls and the dancers with a lower BMI and a lower fat mass. Circulating plasma leptin level depends on BMI and is not a direct determinant of BMD in Chinese adolescent dancers.

Objective To provide the acute toxicity data of hygromycin B phosphotransferase (HPT) using recombinant protein purified from E. coli. Methods Recombinant HPT protein was expressed and purified from E. coli. To exclude the potential adverse effect of bacteria protein in recombinant HPT protein, bacterial control plasmid was constructed, and bacteria control protein was extracted and prepared as recombinant HPT protein. One hundred mice, randomly assigned to 5 groups, were administrated 10 g/kg, 5 g/kg, or 1 g/kg body weight of HPT or 5 g/kg body weight of bacterial control protein or phosphate-buffered saline (PBS) respectively by oral gavage. Results All animals survived with no significant change in body weight gain throughout the study. Macroscopic necropsy examination on day 15 revealed no gross pathological lesions in any of the animals. The maximum tolerated dose (MTD) of HPT was 10 g/kg body weight in mice and could be regarded as nontoxic. Conclusion HPT protein does not have any safety problems to human health.

Background Vitamin A plays an important role in the periods of rapid cellular growth and differentiation, especially during pregnancy, which is supplied by the mother to the fetus. The aim of this study is to assess the prevalence and potential influence factors of prenatal VAD of Chinese pregnant women. Methods China National Nutrition and Health Survey 2010–2013(CHNNS2010–2013) is a nationally representative cross-sectional study. It involved the random selection of 150 districts (urban) or counties (rural). Each site randomly selected 30 pregnant women. Because volume of blood and incomplete data was taken into consideration,the final sample was formed by 1209 participants. Serum retinol concentrations were measured by high performance liquid chromatography. Characteristics of the pregnant women were collected by a questionnaire. Comparing retinol level across categories of independent variables was tested by the Mann-Whitney U test. Logistic and linear regression analyses were used to identify influence factors of Chinese pregnant women. Results The mean serum retinol level of the pregnant women was 1.63 μmol/L (95 % CI 1.60–1.67) and 64[5.3 % (95 % CI 4.03–6.56)] had VAD. The odds of VAD were significantly higher among the pregnant women in the poor rural areas and without college or university education and low- income. Pregnant women in the second and third trimester had 2.40 (95 % CI 1.05–5.46) and 2.82 (95 % CI 1.34–5.93) times increased odds of VAD compared with those in the first trimester respectively. Pregnant women of drinker had 3.10(1.65–5.81) times increased odds of VAD compared with those no drinker. Pregnant smokers had 5.68 (95 % CI 2.23–14.49) times higher odds of VAD compared with pregnant with non-smoker without passive smoking. Conclusions VAD is of mild public-health issue in Chinese pregnant women. Such as : in the poor rural areas and without received college or university education and low- income and advanced gestational age and unhealthy lifestyles of pregnant women such as smoking and drinking. These were pertinent influence factors of VAD.

The objective of this research was to study the effectiveness of NaFeEDTA-fortified soy sauce for controlling iron deficiency in a high-risk population. This was an 18-month, randomized, placebo-controlled intervention trial in 14,000 residents aged three years or older in Bijie City, Guizhou Province, China, using sodium-iron ethylene diamine tetraacetate (NaFeEDTA)-fortified soy sauce (29.6 mg Fe/100 ml). The study data included measurements of food consumption, hemoglobin, serum ferritin, and serum retinol. The results showed that the diet consisted primarily of cereals, fruits, and vegetables, with very little meat. Food consumption remained unchanged during the study period and was similar in the fortified and control groups. The average daily soy sauce consumption of the group consuming the fortified product was 16.4 ml per person, which provided 4.9 mg of iron from NaFeEDTA. At the end of the trial, all age and sex subgroups receiving NaFeEDTA had significantly higher hemoglobin levels, a lower prevalence of anemia, and higher plasma ferritin levels than the controls. The effects became statistically significant after six months of intervention and were maintained throughout the study period. We conclude that NaFeEDTA-fortified soy sauce was highly effective in controlling iron deficiency and reducing the prevalence of iron-deficiency anemia in men, women, and children. NaFeEDTA-fortified soy sauce is affordable and was well accepted by the study population.

A rapid, accurate, and high performance method of high resolution sector field inductively coupled plasma mass spectrometry (HR-ICP-MS) combined with a small-size sample (0.1 mL) preparation was established. The method was validated and applied for the determination of 16 selected plasma trace elements (Fe, Cu, Zn, Rb, B, Al, Se, Sr, V, Cr, Mn, Co, As, Mo, Cd, and Pb). The linear working ranges were over three intervals, 0-1 μg/L, 0–10 μg/L and 0–100 μg/L. Correlation coefficients (R2) ranged from 0.9957 to 0.9999 and the limits of quantification (LOQ) ranged from 0.02 μg/L (Rb) to 1.89 μg/L (Se). The trueness (or recovery) spanned from 89.82% (Al) to 119.15% (Se) and precision expressed by the relative standard deviation (RSD %) for intra-day ranging from 1.1% (Zn) to 9.0% (Se), while ranged from 3.7% (Fe) to 12.7% (Al) for interday. A total of 440 plasma samples were collected from Chinese National Nutrition and Health Survey Project 2002 (CNNHS 2002), which represented the status of plasma trace elements for the children aged 3–12 years from China economical developed rural areas. The concentrations of 16 trace elements were summarized and compared by age groups and gender, which can be used as one of the basic components for the formulation of the baseline reference values of trace elements for the children in 2002.

In the present work, we evaluated the chronic effects of the transgenic insect-resistant rice carrying Cry1Ac and sck genes on Sprague-Dawley (SD) rats through a 78-week feeding study. Based on the gender and weight, 180 SD rats were randomly and evenly assigned into three groups. GM rice and non-GM rice were separately formulated into diets at high levels. AIN-93 diet was used as a nutritional control. Body weight, food consumption, hematology and serum chemistry were monitored regularly. Rats were sacrificed for organ weight measurement and pathological examination at 52 weeks and 78 weeks. Body weight, food consumption, mortality rates, tumor incidences and pathological findings showed no significant difference among the three groups. Although certain differences in some hematology, serum chemistry parameters and relative organ weights were observed between GM rice group and control groups, they were not considered as treatment-related. Taken together, long-term intake of transgenic rice carrying Cry1Ac and sck genes at a high level exerts no unintended adverse effects on rats.

Background This study was to observe the non-heme iron absorption and biological utilization from typical whole Chinese diets in young Chinese healthy urban men, and to observe if the iron absorption and utilization could be affected by the staple food patterns of Southern and Northern China. Materials and Methods Twenty-two young urban men aged 18–24 years were recruited and randomly assigned to two groups in which the staple food was rice and steamed buns, respectively. Each subject received 3 meals containing approximately 3.25 mg stable 57FeSO4 (the ratio of 57Fe content in breakfast, lunch and dinner was 1:2:2) daily for 2 consecutive days. In addition, approximately 2.4 mg 58FeSO4 was administered intravenously to each subject at 30–60 min after dinner each day. Blood samples were collected from each subject to measure the enrichment of the 57Fe and 58Fe. Fourteen days after the experimental diet, non-heme iron absorption was assessed by measuring 57Fe incorporation into red blood cells, and absorbed iron utilization was determined according to the red blood cell incorporation of intravenously infused 58Fe SO4. Results Non-heme iron intake values overall, and in the rice and steamed buns groups were 12.8 ±2.1, 11.3±1.3 and 14.3±1.5 mg, respectively; the mean 57Fe absorption rates were 11±7%, 13±7%, and 8±4%, respectively; and the mean infused 58Fe utilization rates were 85±8%, 84±6%, and 85±10%, respectively. There was no significantly difference in the iron intakes, and 57Fe absorption and infused 58Fe utilization rates between rice and steamed buns groups (all P>0.05). Conclusion We present the non-heme iron absorption and utilization rates from typical whole Chinese diets among young Chinese healthy urban men, which was not affected by the representative staple food patterns of Southern and Northern China. This study will provide a basis for the setting of Chinese iron DRIs.

BackgroundFerric sodium ethylenediaminetetraacetate (NaFeEDTA) enhances iron absorption in the presence of phytate. However, the amount of NaFeEDTA that would have to be added to a complementary food to provide the necessary intake of iron for an infant or young child if NaFeEDTA were the sole iron fortificant exceeds the Acceptable Daily Intake (ADI) of EDTA for this age group. EDTA increases iron absorption at a molar ratio EDTA:iron of less than 1:1.ObjectiveTo determine whether iron absorption is enhanced with a mixture of ferrous sulfate (FeSO4) and NaFeEDTA.MethodsTwo studies with a crossover design were conducted in separate groups of 14 and 15 children aged 24 to 31 months. A complementary food consisting of millet porridge with cabbage, tofu, and pork-filled wheat flour dumplings was fortified with 2 mg iron as either FeSO4or NaFeEDTA (study 1) or 4 mg iron as FeSO4or a mixture of 2 mg each of FeSO4 and NaFeEDTA (study 2). Iron absorption was determined based on erythrocyte incorporation of stable iron isotopes.ResultsIn study 1, the geometric mean (± SD) iron absorption was 8.0% (3.1, 20.8) and 9.2% (3.1, 27.0) from food fortified with FeSO4and NaFeEDTA, respectively. In study 2, iron absorption was significantly higher from food fortified with 4 mg iron as 1:1 mixture of FeSO4/NaFeEDTA than from food fortified with FeSO4; the geometric mean iron absorption was 6.4% (3.0, 13.5) and 4.1% (1.9, 8.9), respectively.ConclusionsThe enhancing effect of EDTA on iron absorption is less strong in composite meals containing enhancers; nevertheless, the equal mixture of FeSO4and NaFeEDTA significantly enhanced iron absorption and can be a strategy to ensure adequate iron absorption from phytate-containing complementary foods.

To determine protein requirement of Chinese young female adults on habitual Chinese diet through indicator amino acid oxidation (IAAO) technique.Twenty women with a mean (SD) age of 21.6 (0.9) years were healthy based on questionnaire, physical examinations and screening tests. There were three consecutive periods of 7 days each with six different intakes of protein (0.70, 0.78, 0.86, 0.94, 1.02 and 1.10 g/kg·d) within Chinese habitual diets (proportions of good-quality protein were 40 to 45%). Subjects were randomly allocated equally into two groups (1.10, 0.86, 0.78 g/kg·d for group 1 and 1.02, 0.94, 0.70 g/kg·d for group 2 from period 1 to period 3 in turn). Adaptation days were from day 1 to day 6 and the isotope study day was day 7 in each period. Amino acid kinetics was measured in non-menstrual periods, based on the IAAO technique. Two indicators (rate of release of 13CO2 and rate of leucine oxidation) were used to estimate protein requirement by breakpoint analysis with a two-phase linear regression crossover model.Mean and population safe protein requirements of Chinese habitual diets in non-menstrual periods from the rate of release of 13CO2 were 0.91 and 1.09 g/kg·d, respectively. And from the rate of leucine oxidation were 0.92 and 1.10 g/kg·d, respectively.The protein requirement of young women on Chinese habitual diets in non-menstrual period was lower than the current protein reference intake for Chinese females. Further studies are necessary to explore female protein requirements during the whole menstrual cycle.

The present study aimed to evaluate the accuracy of the factorial method for estimating energy needs in individuals living in China.Sixteen healthy female adults aged 22.1±1.2 years with a body mass index (kg/m(2)) of 20.4±1.7 were selected as subjects. In free-living conditions, energy expenditure (EE) was determined by using the factorial method. At the same time, the doubly labeled water method (DLW) was also used to measure energy expenditure of the subjects and served as the criterion method. EE predicted by the factorial method (EE(factorial)) was compared with the simultaneous measurement of EE by the validated DLW method (EE(DLW)).There was excellent agreement between EE(factorial) (7.46±0.59 MJ/d) and EE(DLW) (7.64 ± 0.49 MJ/d), with a difference of -2.6±4.9% (-0.18±0.36 MJ/d). No significant differences were found between the two methods. EE(factorial) was highly correlated with EE(DLW) (r=0.795, P0.001) and a good agreement for individuals was found by using the Bland and Altman test.The factorial method gives satisfactory estimates of EE for both groups and individuals living in China.

OBJECTIVE To investigate the association of estrogen receptor alpha (ER-alpha) PvuII polymorphisms with the effect of calcium supplementation on bone development in Chinese pubertal girls, and to study the importance of calcium supplementation by maximizing the peak bone mass at their pubertal stage for bone development and osteoporosis prevention and the role of estrogen in regulating bone mass. METHODS Ninety-four pubertal girls were recruited in the study and divided into two groups and three sub-groups according to the ER-alpha PvuII polymorphisms. One year before and after calcium supplementation, bone mineral density (BMD) was measured by DEXA, while BGP, BAP, TRACP5b, and 25-OH-VitD(3), as well as estrogen were detected by ELISA. Analysis of covariance was used to examine the effect of ER-alpha polymorphisms on bone development. RESULTS The absolute increase and percentage change of BGP were significantly higher in the supplemented group than in the control group (P

China is experiencing a rapid increase in overweight and related conditions. This study describes the geographic variation in BMI levels and the prevalence of overweight and underweight in Chinese adults, and assesses their relations with regional Gross Domestic Product (GDP) per capita levels. BMI values and the prevalence of overweight and underweight in 143 522 adults from the Chinese National Nutrition and Health Survey (2002) were calculated according to geographic regions in China. Their correlations with GDP were assessed. Linear and logistic regressions were used to adjust for age, sex and city–country composition. BMI and the prevalence of overweight were highest in the Bohai coastal regions while lowest in southern provinces such as Guangdong, Guangxi, Yunnan, Hunan and Fujian. Mean BMI values ranged from 20·72 to 25·48 kg/m2, and the prevalence of overweight ranged from 6·6 to 53·9 %. BMI and the prevalence of overweight were positively correlated with economic development, particularly in the northern regions. However, for regions with similar GDP per capita levels, those in the south had substantially lower BMI and lower prevalence of overweight than those in the north. Interestingly, some southern regions with high GDP per capita had low BMI and low prevalence of overweight. The prevalence of underweight was highest in the south. Substantial geographic variations in the prevalence of overweight and underweight exist in China. Such variations cannot be fully explained by the differences in economic status. China is currently facing challenges of both overweight and underweight but priorities vary in different regions.

Since national figures on the occurrence of metabolic syndrome among Chinese adolescents are lacking, this study aims to estimate its prevalence and distribution among Chinese youngsters. The 2002 China National Nutrition and Health Survey is a nationally representative cross-sectional study. Applying the criteria for US adolescents, we estimated the prevalence of metabolic syndrome among 2761 adolescents aged 15 to 19 years. The prevalence of metabolic syndrome among Chinese adolescents overall was 3·7 % (10 % in US adolescents). It was 35·2 %, 23·4 % and 2·3 % among adolescents who were overweight (BMI ≥ 95th percentile), at risk of overweight (BMI between 85th and 95th percentile) and normal weight (BMI below the 85th percentile), respectively. Urban boys had the highest rate (5·8 %) compared with girls and rural youngsters. Among adolescents who had a BMI ≥ 85th percentile and one or two parent(s) with metabolic syndrome, the prevalence was 46·4 %. A total of 96 % of overweight adolescents had at least one and 74·1 % overweight adolescents had at least two abnormalities of metabolic syndrome. Based on these figures, it is estimated that more than three million Chinese adolescents have metabolic syndrome. Both overweight and metabolic syndrome prevalence among adolescents are still relatively low in China, but the prevalence of metabolic syndrome among Chinese overweight adolescents is similar to those living in the USA.