[Study on vitamin A nutritional status of Chinese urban elderly residents in 2010-2012].

Objective: To assess the vitamin A nutritional status of the Chinese urban elderly population by analyzing serum retinol level in 2010-2012. Methods: Data were collected from the Chinese National Nutrition and Health Survey in 2010-2012. Using the multi-stage stratified cluster sampling method, serum samples from elderly residents aged ≥60 years old were obtained from 34 metropolis and 41 middle-sized and small cities. Demographic data were collected using a questionnaire survey. The serum retinol concentration was determined by high-performance liquid chromatography. Vitamin A deficiency (VAD) was determined using the World Health Organization guidelines. A total of 3 200 elderly residents were included in the study. The serum retinol levels and prevalence of VAD and marginal VAD were also compared. Results: The serum retinol concentration (P(50)(P(25)-P(75))) of Chinese urban elderly residents was 1.83 (1.37-2.39) µmoL/L. Compared with middle-sized and small cities (1.91 (1.47-2.48) µmol/L), the retinol level of senior citizens in metropolis (1.70 (1.25-2.25) µmol/L) was significantly lower (P<0.001). The serum retinol levels of elderly male (1.89 (1.37-2.47) µmoL/L) was significantly higher than that of female (1.80 (1.36-2.28) µmoL/L) (P=0.001). The serum retinol concentration was 1.87 (1.42-2.43), 1.78 (1.32-2.33), and 1.71 (1.24-2.24) µmol/L for 60-69, 70-79, and ≥80 years olds, respectively. The retinol level in elderly people ≥70 years olds was significantly lower than that of 60-69 years olds (P<0.001). The overall prevalence of VAD among Chinese urban elderly residents was 4.22% (135/3 200); 6.00% (81/1 350) for metropolis residents and 2.92% (54/1 850) for middle-sized and small city residents. The overall marginal VAD rate of Chinese urban elderly residents was 8.19% (262/3 200); 10.51% (142/1 350) for metropolis residents and 6.49% (120/1 850) for medium-sized and small city residents. The prevalence of VAD and marginal VAD for males was 3.87% (61/1 577) and 8.24% (130/1 577), respectively (P<0.05). The prevalence of VAD according to age group was 3.65% (72/1 975), 4.96% (50/1 008), and 5.99% (13/217), respectively(P=0.097). The prevalence of marginal VAD according to age group was 6.99% (138/1 975), 9.82% (99/1 008), and 11.52% (25/217), respectively(P=0.05). Conclusion: Chinese urban elderly residents showed various levels of VAD, although marginal VAD was quite common. As VAD was more common in metropolis residents and older residents, specific strategies should target these populations.

[Study on anemia and vitamin A and vitamin D nutritional status of Chinese urban pregnant women in 2010-2012].

Objective: To evaluate the prevalence of anemia and the nutritional status of vitamins A and D by analyzing hemoglobin, serum retinol, and serum 25-hydroxyvitamin D levels in Chinese urban pregnant women during 2010-2012. Methods: Data were obtained from the China Nutrition and Health Survey in 2010-2012. Using multi-stage stratified sampling and population proportional stratified random sampling, 2 250 pregnant women from 34 metropolis and 41 middle-sized and small cities were included in this study. Information was collected using a questionnaire survey. The blood hemoglobin concentration was determined using the cyanmethemoglobin method, and anemia was determined using the World Health Organization guidelines combined with the elevation correction standard. The serum retinol level was determined using high-performance liquid chromatography, and vitamin A deficiency (VAD) was judged by the related standard recommended by the World Health Organization. The vitamin D level was determined using enzyme-linked immunosorbent assay and vitamin D deficiency was judged by the recommendation standards from the Institute of Medicine of The National Academies. The hemoglobin, serum retinol, and serum 25-hydroxyvitamin D levels were compared, along with differences in the prevalence of anemia, VAD, and the vitamin D deficiency rate (including deficiency and serious deficiency). Results: A total of 1 738 cases of hemoglobin level, 594 cases of serum retinol level, and 1 027 cases of serum 25-hydroxyvitamin D were available for analysis in this study. The overall blood hemoglobin level (P(50) (P(25)-P(75))) was 122.70 (114.00-131.10) g/L; 123.70 (115.21-132.00) g/L for metropolis and 122.01 (113.30-130.40) g/L for middle-sized and small cities. The blood hemoglobin level of metropolis residents was significantly higher than that of middle-sized and small city residents (P=0.027). The overall prevalence of anemia was 17.0% (295/1 738). The overall serum retinol level (P(50) (P(25)-P(75))) was 1.61 (1.20-2.06) µmol/L; 1.50 (1.04-2.06) µmol/L for metropolis and 1.63 (1.31-2.05) µmol/L for middle-sized and small cities. The serum retinol level of metropolis residents was significantly higher than that of middle-sized and small city residents (P=0.033). The overall prevalence of VAD was 7.4% (47/639); 11.5% (33/286) for metropolis and 4.0% (14/353) for middle-sized and small cities. A significant difference was observed in the prevalence of VAD between metropolis and middle-sized and small city residents (P<0.001). The overall serum 25-hydroxyvitamin D level (P(50) (P(25)-P(75))) was 15.41 (11.79-20.23) ng/ml; 14.71 (11.15-19.07) ng/ml for metropolis and 16.02 (12.65-21.36) ng/ml for middle-sized and small cities. A significant difference was observed in the vitamin D level between metropolis and middle-sized and small city residents (P<0.001). The overall prevalence of vitamin D deficiency was 74.3% (763/1 027); A significant difference was observed in the prevalence of serious vitamin D deficiency between metropolis (30.64%(144/470)) and middle-sized and small city residents (26%(267/1 027))(P=0.002). There were no significant differences between blood hemoglobin level and the prevalence of anemia, VAD, and vitamin D deficiency. Conclusion: The prevalence of anemia in Chinese urban pregnant women improved from 2002 to 2012. The prevalence of vitamin D deficiency in pregnant women was generally more serious, while a certain percentage of women had VAD. The prevalence of VAD and serious vitamin D deficiency among pregnant women from metropolis was significantly higher than that of pregnant women from medium and small-sized cities.

[The vitamin D nutritional status in Chinese urban women of child-bearing age from 2010 to 2012].

Objective: To evaluate the vitamin D nutritional status in Chinese women of child-bearing age by analyzing serum 25-hydroxyvitamin D level in 2010-2012. Methods: Data were obtained from the China Nutrition and Health Survey in 2010-2012. Using cluster sampling and proportional stratified random sampling, 1 514 women of child-bearing age (18-44 years old) from 34 metropolis and 41 small and medium-sized cities were included in this study. Demographic information was collected by questionnaire and serum 25-hydroxyvitamin D concentration was determined by radioimmunoassay, in accordance with the 2010 Institute of Medicine of the National Academies standards. We compared differences in vitamin D levels, specifically serious deficiency, lack of deficiency, insufficiency, and excess. Results: The overall serum 25-hydroxyvitamin D level of Chinese urban women of child-bearing age (P(50) (P(25)-P(75))) was 20.1 (15.1-26.3) ng/ml; minorities had a significantly higher serum 25-hydroxyvitamin D level of 22.0 (15.9-27.5) ng/ml compared with women of Han nationality (19.8 (14.9-26.2) ng/ml) (χ(2)=7.02, P=0.008). The proportions of women with serious deficiency, lack of deficiency, insufficiency, and excess vitamin D were 11.6% (n=175), 37.9% (n=574), 35.1% (n=531), and 0.3% (n=5), respectively. Only 15.1% (n=229) of women of child-bearing age had normal vitamin D nutritional status. No significant differences in vitamin D nutritional status were observed according to age, body mass index, city, nationality, educational level, marital status, or household income per capita (P>0.05). Conclusion: Most Chinese urban women of child-bearing age have poor vitamin D levels and require vitamin D supplementation.