Hypovitaminosis D in pregnancy: Is it a public health issue?

Abstract Objectives: to measure the prevalence of hypovitaminosis D in healthy pregnant women and to analyze the association among some variables and the levels of vitamin D. Methods: an analytical cross-sectional study. 174 healthy pregnant women were selected from four basic health units in São Luís, Brazil, from January to February 2017. The participants answered a questionnaire about sociodemographic and obstetric data. A blood sample was collected to evaluate the plasmatic level of vitamin D. The association between independent variables and the outcome was evaluated by using the Student’s t-test and Chisquare test. Results: the mean of vitamin D concentration was 24.9±6.6ng/ml. Forty women (23.0%) presented vitamin D sufficiency, 93 (53.4%) insufficient, and 41 (23.6%) with deficiency. There was a difference in the vitamin D concentration between evangelical (23.1 ng/ml) and non-evangelical (25.5 ng/ml) (p=0.02) and between primigravida (23.8 ng/ml) and non-primigravida (25.7 ng/ml) (p=0.03). There was a difference in the hypovitaminosis D between adolescents (89.7%) and non-adolescents (72.6%) (p=0.02) and between primigravida (85.0%) and non-primigravida (69.2%) (p=0.01). Low monthly income per capita was associated with a higher frequency of vitamin D sufficiency. Conclusions: Due to the impact of inadequate levels of vitamin D in pregnant women and their babies’ health, even in an equatorial city, hypovitaminosis D in pregnant women is an important public health issue.

摘要
研究目的：测定健康孕妇维生素D缺乏（hypovitaminosis D）的患病率，并分析部分变量与维生素D水平的相关性。
研究方法：本研究为分析性横断面研究。2017年1月至2月，从巴西圣路易斯市4个基层卫生单位纳入174名健康孕妇作为研究对象。参与者填写包含社会人口学及产科资料的调查问卷，采集血液样本以检测血浆维生素D水平。采用t检验（Student’s t-test）与卡方检验（Chi-square test）分析自变量与结局指标的关联。
研究结果：受试者血浆维生素D浓度均值为24.9±6.6ng/ml。其中40名（23.0%）维生素D水平充足，93名（53.4%）维生素D不足，41名（23.6%）存在维生素D缺乏。福音派信徒与非福音派信徒的维生素D浓度存在显著差异（分别为23.1 ng/ml与25.5 ng/ml，p=0.02）；初产妇与非初产妇的维生素D浓度亦存在显著差异（分别为23.8 ng/ml与25.7 ng/ml，p=0.03）。青少年孕妇与非青少年孕妇的维生素D缺乏患病率存在显著差异（分别为89.7%与72.6%，p=0.02），初产妇与非初产妇的维生素D缺乏患病率同样存在显著差异（分别为85.0%与69.2%，p=0.01）。月人均低收入与维生素D充足的高发生率相关。
研究结论：鉴于维生素D水平异常对孕妇及其子代健康的不良影响，即便地处赤道城市，孕妇维生素D缺乏仍是一项重要的公共卫生问题。