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, Wuhan, China.
Department of Clinical Nutrition, People's Hospital of Sanya City, Sanya, China.
Matern Child Nutr. 2020 Jul;16(3):e12987. doi: 10.1111/mcn.12987. Epub 2020 Mar 5.
Vitamin D deficiency has been reported to be associated with respiratory tract infection (RTI). However, evidence regarding the effects of vitamin D supplementation on susceptibility of infants to RTI is limited. In this prospective birth cohort study, we examined whether vitamin D supplementation reduced RTI risk in 2,244 infants completing the follow-up from birth to 6 months of age. The outcome endpoint was the first episode of paediatrician-diagnosed RTI or 6 months of age when no RTI event occurred. Infants receiving vitamin D supplements at a daily dose of 400-600 IU from birth to the outcome endpoint were defined as vitamin D supplementation and divided into four groups according to the average frequency of supplementation: 0, 1-2, 3-4, and 5-7 days/week. We evaluated the relationship between vitamin D supplementation and time to the first episode of RTI with Kaplan-Meier plots. The associations of vitamin D supplementation with infant RTI, lower RTI (LRTI), and RTI-related hospitalization were assessed using modified Poisson regression. The median time to first RTI episode was 60 days after birth (95% CI [60, 90]) for infants without supplementation and longer than 6 months of age for infants with supplementation (p < .001). We observed inverse trends between supplementation frequency and risk of RTI, LRTI, and RTI-related hospitalization (p for trend < .001), with the risk ratios in the 5-7 days/week supplementation group of 0.46 (95% CI [0.41, 0.50]), 0.17 (95% CI [0.13, 0.24]), and 0.18 (95% CI [0.12, 0.27]), respectively. These associations were significant and consistent in a subgroup analysis stratified by infant feeding.
维生素 D 缺乏与呼吸道感染（RTI）有关。然而，关于维生素 D 补充对婴儿 RTI 易感性影响的证据有限。在这项前瞻性出生队列研究中，我们研究了维生素 D 补充是否可以降低 2244 名婴儿在从出生到 6 个月大的随访期间发生 RTI 的风险。结局终点是儿科医生诊断的第一次 RTI 发作或 6 个月时未发生 RTI 事件。从出生到结局终点每天接受 400-600IU 维生素 D 补充的婴儿被定义为接受维生素 D 补充，并根据补充的平均频率分为四组：0、1-2、3-4 和 5-7 天/周。我们使用 Kaplan-Meier 图评估了维生素 D 补充与首次 RTI 发作时间之间的关系。使用修正泊松回归评估了维生素 D 补充与婴儿 RTI、低 RTI（LRTI）和 RTI 相关住院的关系。无补充婴儿首次 RTI 发作的中位时间为出生后 60 天（95%CI[60，90]），而补充婴儿的中位时间长于 6 个月（p<.001）。我们观察到补充频率与 RTI、LRTI 和 RTI 相关住院的风险之间呈反比趋势（趋势检验 p<.001），每周 5-7 天补充组的风险比分别为 0.46（95%CI[0.41，0.50]）、0.17（95%CI[0.13，0.24]）和 0.18（95%CI[0.12，0.27]）。这些关联在按婴儿喂养分层的亚组分析中是显著且一致的。
