Nwaru Bright I, Hadkhale Kishor, Hämäläinen Niina, Takkinen Hanna-Mari, Ahonen Suvi, Ilonen Jorma, Toppari Jorma, Niemelä Onni, Haapala Anna-Maija, Veijola Riitta, Knip Mikael, Virtanen Suvi M
Faculty of Social Sciences/Health, University of Tampere, Tampere, Finland.
Asthma UK Centre for Applied Research, Centre for Medical Informatics, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Edinburgh, UK.
Pediatr Allergy Immunol. 2017 Nov;28(7):641-648. doi: 10.1111/pai.12773. Epub 2017 Sep 8.
Early-life vitamin D intake has been linked to asthma risk in childhood, but the role of longitudinal vitamin D exposure has not been previously evaluated. We investigated the association between vitamin D intake during the first 4 years of life and asthma risk by age 5.
Within a Finnish population-based birth cohort, 182 incident asthma cases were matched to 728 controls on sex, genetic risk for type 1 diabetes, delivery hospital, and time of birth. Vitamin D intake was assessed by age-specific 3 day food records. Parents completed a validated version of the International Study of Asthma and Allergies in Childhood questionnaire at 5 years.
At 3 months, supplements were the main source of vitamin D intake; intake from foods increased from 3 months on, mainly from fortified milk products. Vitamin D intake at each specific age was associated with an increased risk of any asthma, atopic, and non-atopic asthma, but only intake at 1 and 2 years was statistically significantly associated with asthma. Longitudinal vitamin D intake was associated with an increased risk of asthma (OR 1.24; 95%CI 1.00-1.53).
Increased vitamin D intake in childhood, particularly intake at 1 and 2 years of age, may increase risk of childhood asthma. This might reflect a true effect or residual confounding by lifestyle or environmental factors. Repeated assessment of vitamin D intake allowed evaluation of the longitudinal and age-dependent impact of vitamin D on the risk of asthma. Further longitudinal studies are required to confirm or question these findings.
儿童早期维生素D摄入量与儿童哮喘风险有关，但纵向维生素D暴露的作用此前尚未得到评估。我们调查了生命最初4年的维生素D摄入量与5岁时哮喘风险之间的关联。
在芬兰一项基于人群的出生队列中，182例新发哮喘病例在性别、1型糖尿病遗传风险、分娩医院和出生时间方面与728例对照进行匹配。通过特定年龄的3天食物记录评估维生素D摄入量。父母在孩子5岁时完成了一份经过验证的儿童哮喘和过敏国际研究问卷。
在3个月时，补充剂是维生素D摄入的主要来源；从3个月起食物中的摄入量增加，主要来自强化乳制品。每个特定年龄的维生素D摄入量与任何哮喘、特应性哮喘和非特应性哮喘的风险增加相关，但只有1岁和2岁时的摄入量与哮喘有统计学显著关联。纵向维生素D摄入量与哮喘风险增加相关（比值比1.24；95%置信区间1.00 - 1.53）。
儿童期维生素D摄入量增加，尤其是1岁和2岁时的摄入量，可能会增加儿童哮喘风险。这可能反映了一种真实效应，也可能是生活方式或环境因素导致的残余混杂。对维生素D摄入量的重复评估使得能够评估维生素D对哮喘风险的纵向和年龄依赖性影响。需要进一步的纵向研究来证实或质疑这些发现。
