Lancet：母亲孕期血VitD浓度不影响其后代骨矿物质含量

孕期母体Vit D状态是决定其后代骨矿物质含量（BMC）的提示因素，但是上述结果仅经小样本量的研究证实。来自英国Bristol大学的Debbie A Lawlor等拟设计在大样本量的人群中进行前瞻性研究以确定上述联系是否存在，他们的研究结果发表在The Lancet 3月的在线期刊上。
本研究的受试者的数据来自于Avon父母与儿童纵向研究中，在该研究中母亲（单胎孕母）在孕期接受过25(OH)D浓度测定，其后代在9-10岁时接受双能X线骨密度测定。在孕期25（OH）D浓度大于50.00nmol/L为充足，25（OH）D浓度在27.50至49.99nmol/L之间为不足，25（OH）D小于27.50nmol/L为缺乏。研究者每三个月对孕期母体25（OH）D浓度和后代TBLH和脊椎BMC之间的联系进行评定。
共有3960对母亲极其后代被纳入研究的最后评估，他们主要是欧洲白种人，其中3960对被纳入LH BMC评估，3196对被纳入脊椎BMC评估。进行评估时，儿童的中位年龄为9.9岁。母亲在孕期的Vit D状态如下：2644名（77%）母亲为Vit D充足，1096名（28%）母亲为Vit D不足，220名（6%）母亲为Vit D缺乏，但是研究结果提示，与Vit D充足的母亲后代相比，Vit D不足或缺乏的母亲的后代的TBLH和脊椎BMC并不存在显著差异。后代BMC与母亲孕期Vit D浓度不存在显著相关性。
本研究结果提示，孕期母亲Vit D浓度与其后代儿童期BMC之间不存在显著相关性。

Association of maternal vitamin D status during pregnancy with bone-mineral content in offspring: a prospective cohort study
Original Text
Prof Debbie A Lawlor PhD a b , Andrew K Wills PhD a b, Abigail Fraser PhD a b, Adrian Sayers MSc b, Prof William D Fraser MD c, Prof Jonathan H Tobias PhD d
Background
Maternal vitamin D status in pregnancy is a suggested determinant of bone-mineral content (BMC) in offspring, but has been assessed in small studies. We investigated this association in a large prospective study.
Methods
Eligible participants were mother-and-singleton-offspring pairs who had participated in the Avon Longitudinal Study of Parents and Children, and in which the mother had recorded measurements of 25(OH)D concentration in pregnancy and the offspring had undergone dual-energy x-ray absorptiometry at age 9—10 years. 25(OH)D concentrations in pregnancy were assessed per 10·0 nmol/L and classified as sufficient (more than 50·00 nmol/L), insufficient (49·99—27·50 nmol/L), or deficient (lower than 27·50 nmol/L). Associations between maternal serum 25(OH)D concentrations and offspring total body less head (TBLH) and spinal BMC were assessed by trimester.
Results
3960 mother-and-offspring pairs, mainly of white European origin, were assessed (TBLH BMC n=3960, spinal BMC n=3196). Mean offspring age was 9·9 years. 2644 (77%) mothers had sufficient, 1096 (28%) insufficient, and 220 (6%) deficient 25(OH)D concentrations in pregnancy, but TBLH and spinal BMC did not differ between offspring of mothers in the lower two groups versus sufficient 25(OH)D concentration. No associations with offspring BMC were found for any trimester, including the third trimester, which is thought to be most relevant (TBLH BMC confounder-adjusted mean difference −0·03 g per 10·0 nmol/L, 95% CI −1·71 to 1·65; spinal BMC 0·04 g per 10·0 nmol/L, 95% CI −0·12 to 0·21).
Conclusions
We found no relevant association between maternal vitamin D status in pregnancy and offspring BMC in late childhood.