High prevalence of vitamin D insufficiency in pregnant women working indoors and residing in Guiyang, China

摘要

Background/Aim: To assess the status of 25-hydroxyvitamin D [25(OH)D] in pregnant women in their second and third trimesters, who reside and work indoors in Guiyang, China. Subjects and methods: A total of 311 pregnant women in their 12th to 40th gestational week were engaged in employment located indoors in the urban area of Guiyang and completed a questionnaire on living habits. Levels of serum 25(OH)D were measured from fasting venous blood by liquid chromatography-mass spectrometry (LC-MS/MS). Levels of 25(OH)D were classified as vitamin D deficient [25(OH)D20 ng/ml], insufficient [20 ng/ml≤25(OH)D30 ng/ml], or sufficient [25(OH)D≥30 ng/ml]. Results: The mean serum level of 25(OH)D was 14.69±6.81 ng/ml. Vitamin D deficiency, insufficiency and sufficiency were found in 260 (83.6%), 39 (12.5%), and 12 (3.9%) women, respectively. The mean level of 25(OH)D in the third trimester was significantly higher than in the second trimester (p0.001). The mean 25(OH)D level in summer (June, July, August) was significantly higher than in the other seasons (p0.001). The 25(OH)D level in pregnant women compliant with pre-natal calcium or multi-vitamin supplements was higher than in those not taking supplements (p0.001). Conclusions: These results suggest that pregnant women residing in Guiyang urban area and working indoors are at high risk of vitamin D insufficiency, particularly during spring, winter, and autumn, regardless of use of pre-natal calcium and multivitamins. Appropriate vitamin D supplementation is necessary to improve maternal vitamin D nutrition.