Pediatrics：补充维生素D可降低儿童呼吸道感染的风险

最新一项研究证实儿童每天补充维生素D可减少在冬季患呼吸道感染的风险。相关研究论文发表在Pediatrics杂志上，研究揭示血液中维生素D水平的低的儿童补充维生素D能降低呼吸道感染风险。

麻省总医院（MGH）医学博士Carlos Camargo说：我们的随机对照试验表明，维生素D对呼吸道感染风险有重要影响，我们发现近250名血液中维生素D低的儿童在冬季每天服用维生素D补充剂能使得呼吸道感染的风险降低一半。

最近的几项研究表明，维生素D主要作用是强健骨骼，此外还有免疫功能作用。Camargo和其他研究人员的研究维生素D水平较高与导致呼吸道感染如感冒或流感的风险降低相关联，但这样的观察性研究并不能证明维生素能防止感染的发生。这样的研究证据来自随机对照试验，具体就是比较两个相似的人群，要么接受或不接受干预措施如补充维生素D。第一个这样的试验在日本学童中间开展，其结果实模棱两可的，简而言之就是维生素D补充剂能导致某一种类型的流感风险降低，但并不会影响另一种类型，因此许多组织都要求进一步开展随机试验来解决上述问题。

该研究设计提供了强有力的证据表明低的维生素D和呼吸道感染有因果关系，维生素D水平低的儿童补充维生素D能防止一些呼吸道感染。研究人员指出，在这项研究中的维生素D剂量高于每日推荐剂量（每日300 IU），因为美国医学研究所提出儿童的推荐剂量为400 IU，其他研究团队推荐的每日剂量高达1,000 IU。

拓展阅读;

          NEJM: 大剂量的维生素D才能降低骨折风险

          Am J Resp Crit Care：维生素D或能阻止吸烟者肺部功能损伤

          JCEM：维生素D与钙减少老年人死亡率

          JCI：维生素D对骨质疏松症的双刃剑作用

          JCO：适当补充维生素D降低患结直肠癌风险

          维生素D与心血管健康？

编译自：Vitamin D Supplementation Can Decrease Risk of Respiratory Infections in Children

doi:10.1542/peds.2011-3029
PMC:
PMID:

Randomized Trial of Vitamin D Supplementation and Risk of Acute Respiratory Tract Infection in Mongolia.

Carlos A. Camargo Jr, Davaasambuu Ganmaa, A. Lindsay Frazier, Franca F. Kirchberg, Jennifer J. Stuart, Ken Kleinman, Nyamjav Sumberzul, and Janet W. Rich-Edwards.

OBJECTIVE: Observational studies suggest that serum levels of 25-hydroxyvitamin D (25[OH]D) are inversely associated with acute respiratory tract infections (ARIs). We hypothesized that vitamin D supplementation of children with vitamin D deficiency would lower the risk of ARIs.

METHODS: By using cluster randomization, classrooms of 744 Mongolian schoolchildren were randomly assigned to different treatments in winter (January–March). This analysis focused on a subset of 247 children who were assigned to daily ingestion of unfortified regular milk (control; n = 104) or milk fortified with 300 IU of vitamin D₃ (n = 143). This comparison was double-blinded. The primary outcome was the number of parent-reported ARIs over the past 3 months.

RESULTS: At baseline, the median serum 25(OH)D level was 7 ng/mL (interquartile range: 5–10 ng/mL). At the end of the trial, follow-up was 99% (n = 244), and the median 25(OH)D levels of children in the control versus vitamin D groups was significantly different (7 vs 19 ng/mL; P < .001). Compared with controls, children receiving vitamin D reported significantly fewer ARIs during the study period (mean: 0.80 vs 0.45; P = .047), with a rate ratio of 0.52 (95% confidence interval: 0.31–0.89). Adjusting for age, gender, and history of wheezing, vitamin D continued to halve the risk of ARI (rate ratio: 0.50 [95% confidence interval: 0.28–0.88]). Similar results were found among children either below or above the median 25(OH)D level at baseline (rate ratio: 0.41 vs 0.57; P_interaction = .27).

CONCLUSIONS: Vitamin D supplementation significantly reduced the risk of ARIs in winter among Mongolian children with vitamin D deficiency.