Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety and the Ministry of Education (MOE) Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, China.
Department of Clinical Nutrition, People's Hospital of Sanya City, 558 Jiefang Road, Sanya, China.
Infection. 2023 Feb;51(1):109-118. doi: 10.1007/s15010-022-01845-4. Epub 2022 May 24.
To assess the association between vitamin D (VD) supplementation and the risk of lower respiratory tract infection (LRTI) among infants.
This is a nested case-control study from an ongoing prospective birth cohort in Wuhan from 2013. Cases were subjects free of neonatal pneumonia but later developed LRTI during infancy, who were matched with five randomly selected controls by infant sex, birth year, and birth season. We included 190 cases and 950 controls in the final analysis. The primary outcome was the first LRTI incident and the exposure was VD supplementation from birth to the index endpoint. The association between VD supplementation and LRTI risk was assessed using the Cox proportional-hazards regression model.
Infants taking supplements had a 59% relative reduction in the hazard ratio of LRTI (HR = 0.41; 95% CI 0.26, 0.64) compared to those not supplemented. There was a linear relationship between LRTI risk and VD supplementation within range of 0-603 IU/day: for each 100 IU per day increment in VD supplementation, infants experienced a 21% lower risk of developing LRTI (adjusted HR: 0.79; 95% CI 0.71, 0.89). The linear relationship was stably observed in the sensitivity analyses as well.
VD supplementation was associated with the reduced risk of LRTI throughout infancy, and the optimal supplementation dose for infants may be beyond the current recommendation.
评估维生素 D（VD）补充与婴儿下呼吸道感染（LRTI）风险之间的关联。
这是一项来自武汉正在进行的前瞻性出生队列的嵌套病例对照研究。病例为无新生儿肺炎但在婴儿期后发生 LRTI 的受试者，通过婴儿性别、出生年份和出生季节与 5 名随机选择的对照匹配。我们最终分析包括 190 例病例和 950 例对照。主要结局是首次 LRTI 事件，暴露是从出生到指数终点的 VD 补充。使用 Cox 比例风险回归模型评估 VD 补充与 LRTI 风险之间的关联。
与未补充的婴儿相比，服用补充剂的婴儿 LRTI 的风险比相对降低了 59%（HR=0.41；95%CI 0.26，0.64）。在 0-603 IU/天的 VD 补充范围内，LRTI 风险与 VD 补充之间存在线性关系：VD 补充每天增加 100 IU，婴儿患 LRTI 的风险降低 21%（调整后的 HR：0.79；95%CI 0.71，0.89）。在敏感性分析中也稳定观察到了线性关系。
VD 补充与整个婴儿期 LRTI 风险降低有关，婴儿的最佳补充剂量可能超出当前建议。
