Department of Pediatrics, St Michael’s Hospital, 30 Bond St, 15-014 Cardinal Carter, Toronto, Ontario, Canada.
JAMA Pediatr. 2013 Mar 1;167(3):230-5. doi: 10.1001/2013.jamapediatrics.226.
OBJECTIVES To determine the effect of modifiable dietary intake variables (current vitamin D supplementation and daily cow's milk intake) on 25-hydroxyvitamin D level in early childhood and to evaluate the relationship between these modifiable dietary factors and other largely nonmodifiable determinants of vitamin D status including skin pigmentation and season. DESIGN Cross-sectional study. SETTING Primary care pediatric and family medicine practices participating in the TARGet Kids! practice-based research network in Toronto, Ontario, Canada. PARTICIPANTS From December 2008 to June 2011, healthy children 1 to 5 years of age were recruited during a routine physician's visit. INTERVENTIONS Survey, anthropometric measurements, and laboratory data were collected. A multivariable linear regression model was developed to examine the independent effects of vitamin D supplementation and daily volume of cow's milk on 25-hydroxyvitamin D level. MAIN OUTCOME MEASURES 25-Hydroxyvitamin D level. RESULTS Blood was obtained in 1898 children. Two modifiable dietary intake variables, vitamin D supplementation and cow's milk, increased 25-hydroxyvitamin D level by 3.4 ng/mL (95% CI, 2-4 ng/mL) and 1.6 ng/mL per 250-mL cup per day (95% CI, 1-2 ng/mL), respectively. Two nonmodifiable variables reflecting cutaneous vitamin D synthesis (skin pigmentation and season) were also strongly associated with 25-hydroxyvitamin D status but accounted for a much smaller proportion of the explained variation in 25-hydroxyvitamin D level. The effect of vitamin D supplementation and milk intake on 25-hydroxyvitamin D level appeared similar regardless of skin pigmentation or season. CONCLUSION Two modifiable dietary intake variables (vitamin D supplementation and cow's milk intake) are the most important determinants of 25-hydroxyvitamin D status in early childhood.
确定可改变的饮食摄入变量（当前维生素 D 补充和每日牛奶摄入量）对幼儿 25-羟维生素 D 水平的影响，并评估这些可改变的饮食因素与其他非主要的维生素 D 状态决定因素（包括皮肤色素沉着和季节）之间的关系。
横断面研究。
加拿大安大略省多伦多的 TARGet Kids!基于实践的研究网络中的初级保健儿科和家庭医学实践。
2008 年 12 月至 2011 年 6 月期间，在常规医生就诊期间招募了 1 至 5 岁的健康儿童。
收集了问卷调查、人体测量学测量和实验室数据。采用多元线性回归模型来检验维生素 D 补充剂和每日牛奶量对 25-羟维生素 D 水平的独立影响。
25-羟维生素 D 水平。
共采集了 1898 名儿童的血液样本。两个可改变的饮食摄入变量，维生素 D 补充剂和牛奶，分别使 25-羟维生素 D 水平增加 3.4ng/mL（95%CI，2-4ng/mL）和 1.6ng/mL/每天 250 毫升杯（95%CI，1-2ng/mL）。反映皮肤维生素 D 合成的两个不可改变的变量（皮肤色素沉着和季节）也与 25-羟维生素 D 状态密切相关，但仅占 25-羟维生素 D 水平解释变化的一小部分。维生素 D 补充剂和牛奶摄入量对 25-羟维生素 D 水平的影响似乎与皮肤色素沉着或季节无关。
两个可改变的饮食摄入变量（维生素 D 补充剂和牛奶摄入量）是幼儿 25-羟维生素 D 状态的最重要决定因素。
