Maguire Jonathon L, Birken Catherine S, O'Connor Deborah L, Macarthur Colin, Thorpe Kevin E, Mamdani Muhammad, Parkin Patricia C
Department of Pediatrics, St Michael's Hospital;
Paediatr Child Health. 2011 Feb;16(2):e11-5. doi: 10.1093/pch/16.2.e11.
To determine the prevalence of low vitamin D concentrations in a cohort of healthy two-year-old children living in a large Canadian city, and to explore whether body mass index (BMI) and cow's milk intake are associated with low vitamin D concentrations.
A cross-sectional study was performed on healthy two-year-old children attending a well-child visit in Toronto, Ontario (latitude 43.4°N). Dietary exposures were measured by questionnaire. The primary outcome was the prevalence of low vitamin D concentrations (25-hydroxyvitamin D concentration of lower than 50 nmol/L or lower than 75 nmol/L).
A total of 91 healthy children 24 to 30 months of age were recruited between November 2007 and May 2008. The prevalence of low vitamin D concentrations (lower than 50 nmol/L) was 32% (29 of 92, 95% CI 22% to 42%) and the prevalence of vitamin D concentrations of lower than 75 nmol/L was 82% (75 of 91, 95% CI 73% to 89%). Using multivariable logistic regression, the odds of vitamin D concentrations being lower than 50 nmol/L decreased by 0.44 (95% CI 0.2 to 0.96) for each additional cup of cow's milk intake per day and increased by 1.2 to 2.6 per unit BMI depending on BMI level (P=0.07).
A total of 30% to 80% of toddlers in the present study's urban Canadian setting demonstrated low vitamin D concentrations - the highest prevalence of low vitamin D in toddlers outside of Alaska. Modifiable factors associated with low vitamin D were lower cow's milk intake and higher BMI. The vitamin D status of toddlers in urban Canada may require specific attention.
确定居住在加拿大一个大城市的健康两岁儿童队列中维生素D浓度低的患病率，并探讨体重指数（BMI）和牛奶摄入量是否与低维生素D浓度相关。
对安大略省多伦多市（北纬43.4°）参加健康儿童检查的健康两岁儿童进行了一项横断面研究。通过问卷调查来测量饮食摄入量。主要结局是低维生素D浓度（25-羟维生素D浓度低于50 nmol/L或低于75 nmol/L）的患病率。
在2007年11月至2008年5月期间共招募了91名24至30个月大的健康儿童。维生素D浓度低（低于50 nmol/L）的患病率为32%（92名中的29名，95%可信区间为22%至42%），维生素D浓度低于75 nmol/L的患病率为82%（91名中的75名，95%可信区间为73%至89%）。使用多变量逻辑回归分析，每天每多摄入一杯牛奶，维生素D浓度低于50 nmol/L的几率降低0.44（95%可信区间为0.2至0.96），根据BMI水平，每单位BMI维生素D浓度低于50 nmol/L的几率增加1.2至2.6（P = 0.07）。
在本研究的加拿大城市环境中，共有30%至80%的幼儿维生素D浓度低，这是阿拉斯加以外幼儿中维生素D浓度低的最高患病率。与低维生素D相关的可改变因素是牛奶摄入量较低和BMI较高。加拿大城市中幼儿的维生素D状况可能需要特别关注。
