Relationship between vitamin D knowledge and 25‐hydroxyvitamin D levels amongst pregnant women

Background Pregnant women living at northerly latitudes are at risk of suboptimal vitamin D status. There is a paucity of studies correlating knowledge, attitudes and practices of vitamin D with serum levels amongst pregnant women. We aimed to determine the prevalence of suboptimal vitamin D status in pregnant women of various ethnicities attending two Dublin maternity hospitals and to assess levels of knowledge, attitudes and practices concerning vitamin D. Methods We conducted a cross‐sectional study of 116 pregnant women of Irish, Asian, Sub‐Saharan African and Middle Eastern and North African ( MENA ) origin. Vitamin D status was determined by measurement of serum 25‐hydroxyvitamin D (25 OHD ). We examined knowledge, attitudes and practices concerning vitamin D using an interview‐assisted questionnaire. Results The median ( interquartile range ) 25 OHD level was 25.9 (16.5–44.7) nmol L –1 . Using a cut‐off point of <30 nmol L –1 , the proportion at risk of deficiency was significantly higher among MENA (88%; P  < 0.001) and Sub‐Saharan African women (68%; P  = 0.019) than Irish women (36%). Eighty‐two women (71%) reported they had insufficient knowledge about vitamin D and its sources. Vitamin D containing supplement usage was the strongest predictor of 25 OHD levels ≥30 nmol L –1 ( odds ratio  = 18.03, 95% confidence interval  = 5.7256.8, P  < 0.001). Conclusions Suboptimal vitamin D status is common in this cohort of pregnant women, especially among those of Sub‐Saharan African and MENA origin. Awareness of vitamin D dietary sources is poor among all subgroups. Recommending vitamin D containing supplements may be the best strategy at present for improving vitamin D status with a need for increased vitamin D education.