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

Abstract

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.