Analysis of 25-hydroxyvitamin D levels and their influencing factors in mid-pregnancy women

Abstract

ObjectiveTo investigate the levels of 25-hydroxyvitamin D [25 (OH) D] and its influencing factors in women during mid-pregnancy, and to provide an evidence for improving the vitamin D deficiency in pregnant women.MethodsA total of 220 pregnant women in the second trimester of pregnancy who underwent regular prenatal examinations at the Tianjin Binhai New Area Maternal and Child Health and Family Planning Service Center from February 2022 to February 2023 were selected as the research subjects. Basic clinical data of the pregnant women were collected. A 25 (OH) D level of ≥30 μg·L-1 was considered sufficient, while a level of <30 μg·L-1 was considered insufficient. Univariate analysis and multivariate logistic regression analysis were used to explore the factors influencing changes of 25 (OH) D levels in pregnant women.ResultsThe proportion of mid-pregnancy women with sufficient and insufficient 25 (OH) D levels were 15.9% (35/220) and 84.1% (185/220), respectively. Univariate analysis showed that 25 (OH) D level in mid-pregnancy women was associated with maternal age, season of blood collection, weekly duration of outdoor activities, dietary preferences, calcium supplementation, multivitamin supplementation, and passive or active smoking, and all the differences were statistically significant (all P<0.01). Multivariate logistic regression analysis revealed that women aged ≥35 years (OR=6.242, 95%CI: 2.501‒15.426, P<0.001), with dietary preferences (OR=1.091, 95%CI: 1.034‒1.150, P<0.001), and those who smoked or were exposed to passive smoking (OR=1.217, 95%CI: 1.084‒3.563, P<0.001), or during winter (OR=2.196, 95%CI: 1.593‒3.024, P<0.001) were more likely to have 25 (OH) D deficiency. Conversely, women engaged in ≥10 hours of outdoor activities per week (OR=3.406, 95%CI: 1.818‒5.386, P<0.001), supplemented with calcium (OR=1.811, 95%CI: 1.052‒3.116, P=0.032), and supplemented with multivitamins (OR=3.662, 95%CI: 1.864‒5.386, P<0.001) had a relatively lower risk of 25 (OH) D deficiency. The difference was statistically significant.ConclusionThe incidence of 25 (OH) D deficiency is high in mid-pregnancy women and is primarily associated with maternal age, season of blood collection, weekly duration of outdoor activities, dietary preferences, and supplementation of multivitamins. It is necessary to conduct 25 (OH) D level screening and provide necessary medical interventions and corresponding educational programs for pregnant women.

Keywords

• pregnant women
• second trimester of pregnancy
• 25-hydroxyvitamin d
• pregnancy outcome
• influencing factor