Abstract：
BACKGROUND: The role of maternal vitamin D supplementation in the prevention of infantile rickets is unknown, particularly in low- and middle-income countries without routine infant vitamin D supplementation. Through secondary analysis of a randomized, placebo-controlled trial in Bangladesh, we examined the dose-ranging effects of maternal vitamin D supplementation on the risk of biochemical rickets at 6 to 12 months of age.
METHODS: Pregnant women (n = 1300) were randomized into 5 groups: placebo, or vitamin D 4200 IU/week, 16 800 IU/week, or 28 000 IU/week from second trimester to delivery and placebo until 6 months postpartum; or 28 000 IU/week prenatally and until 6 months postpartum. Infants underwent biochemical rickets screening from 6 to 12 months of age (n = 790). Relative risks (RR) and 95% confidence intervals (95% CI) of biochemical rickets were estimated for each group versus placebo.
RESULTS: Overall, 39/790 (4.9%) infants had biochemical rickets. Prevalence was highest in the placebo group (7.8%), and the risk was significantly lower among infants whose mothers received combined prenatal and postpartum vitamin D at 28 000 IU/week (1.3%; RR, 0.16; 95% CI, 0.03-0.72). Risks among infants whose mothers received only prenatal supplementation (4200 IU, 16 800 IU, 28 000 IU weekly) were not significantly different from placebo: 3.8% (RR, 0.48; 95% CI, 0.19-1.22), 5.8% (RR, 0.74; 95% CI, 0.33-1.69), and 5.7% (RR, 0.73; 95% CI, 0.32-1.65), respectively.
CONCLUSIONS: Maternal vitamin D supplementation (28 000 IU/week) during the third trimester of pregnancy until 6 months postpartum reduced the risk of infantile biochemical rickets. Further research is needed to define optimal postpartum supplementation dosing during lactation.
METHODS: Pregnant women (n = 1300) were randomized into 5 groups: placebo, or vitamin D 4200 IU/week, 16 800 IU/week, or 28 000 IU/week from second trimester to delivery and placebo until 6 months postpartum; or 28 000 IU/week prenatally and until 6 months postpartum. Infants underwent biochemical rickets screening from 6 to 12 months of age (n = 790). Relative risks (RR) and 95% confidence intervals (95% CI) of biochemical rickets were estimated for each group versus placebo.
RESULTS: Overall, 39/790 (4.9%) infants had biochemical rickets. Prevalence was highest in the placebo group (7.8%), and the risk was significantly lower among infants whose mothers received combined prenatal and postpartum vitamin D at 28 000 IU/week (1.3%; RR, 0.16; 95% CI, 0.03-0.72). Risks among infants whose mothers received only prenatal supplementation (4200 IU, 16 800 IU, 28 000 IU weekly) were not significantly different from placebo: 3.8% (RR, 0.48; 95% CI, 0.19-1.22), 5.8% (RR, 0.74; 95% CI, 0.33-1.69), and 5.7% (RR, 0.73; 95% CI, 0.32-1.65), respectively.
CONCLUSIONS: Maternal vitamin D supplementation (28 000 IU/week) during the third trimester of pregnancy until 6 months postpartum reduced the risk of infantile biochemical rickets. Further research is needed to define optimal postpartum supplementation dosing during lactation.
摘要：
■母亲补充维生素D在预防婴儿病方面的作用尚不清楚，特别是在没有常规婴儿维生素D补充剂的低收入和中等收入国家。通过随机的二次分析，孟加拉国的安慰剂对照试验，我们研究了孕妇补充维生素D对6~12月龄时发生生化病风险的剂量范围效应.
■孕妇（n=1300）被随机分为5组：安慰剂，或维生素D4200IU/周，16800IU/周，或28000IU/周，从孕中期到分娩和安慰剂，直到产后6个月;或28000IU/周，直到产后6个月。6至12个月大的婴儿接受了生化病筛查（n=790）。与安慰剂相比，估计每组生化病的相对风险（RR）和95％置信区间（95％CI）。
■总的来说，39/790（4.9％）婴儿有生化性病。安慰剂组患病率最高（7.8%），母亲在28000IU/周时接受产前和产后联合维生素D的婴儿的风险显着降低（1.3％；RR，0.16；95%CI，0.03-0.72）。母亲仅接受产前补充的婴儿的风险(4200IU，16800IU,每周28000IU）与安慰剂没有显着差异：3.8%（RR，0.48；95%CI，0.19-1.22），5.8%（RR，0.74；95%CI，0.33-1.69），和5.7%（RR，0.73；95%CI，0.32-1.65），分别。
■在妊娠晚期至产后6个月期间，母亲补充维生素D（28000IU/周）可降低婴儿生化病的风险。需要进一步的研究来确定泌乳期间的最佳产后补充剂量。
■孕妇（n=1300）被随机分为5组：安慰剂，或维生素D4200IU/周，16800IU/周，或28000IU/周，从孕中期到分娩和安慰剂，直到产后6个月;或28000IU/周，直到产后6个月。6至12个月大的婴儿接受了生化病筛查（n=790）。与安慰剂相比，估计每组生化病的相对风险（RR）和95％置信区间（95％CI）。
■总的来说，39/790（4.9％）婴儿有生化性病。安慰剂组患病率最高（7.8%），母亲在28000IU/周时接受产前和产后联合维生素D的婴儿的风险显着降低（1.3％；RR，0.16；95%CI，0.03-0.72）。母亲仅接受产前补充的婴儿的风险(4200IU，16800IU,每周28000IU）与安慰剂没有显着差异：3.8%（RR，0.48；95%CI，0.19-1.22），5.8%（RR，0.74；95%CI，0.33-1.69），和5.7%（RR，0.73；95%CI，0.32-1.65），分别。
■在妊娠晚期至产后6个月期间，母亲补充维生素D（28000IU/周）可降低婴儿生化病的风险。需要进一步的研究来确定泌乳期间的最佳产后补充剂量。
