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Introduction: There is evidence that 25-hydroxyvitamin D levels are lower in overweight and obese youth. This study examined the relationship between weight status and 25-hydroxyvitamin D, while controlling for confounders, in Canadian youth. Methods: Plasma 25-hydroxyvitamin D from subjects aged 6 to 17 years from the Canadian Health Measures Survey cycles 1 (2007 to 2009) and 2 (2009 to 2011) was used. Sex-specific multiple linear regression and logistic regressions examined the relationship of overweight and obesity (body mass index = 85th percentile) with 25-hydroxyvitamin D levels and the odds of 25-hydroxyvitamin D <40 nmol/L and <50 nmol/L. Results: The prevalence of risk of vitamin D deficiency (25-hydroxyvitamin D < 30 nmol/L) was 6% (95% confidence interval [CI] 3.26% to 10.12%). Vitamin D inadequacy, estimated by levels <40 nmol/L, was 15% (95% CI 10.34% to 20.39%; 19% [95% CI 13.1 to 25.6] for teenagers). Seventy per cent (95% CI 63.59 to 75.17) had levels >50 nmol/L, consistent with achieving the Recommended Dietary Allowance. In adjusted analyses, overweight/obesity (1/3 of subjects) was independently associated with lower 25-hydroxyvitamin D for both sexes after adjustment for age, race, income, season, vitamin D supplementation and daily milk consumption. For 25-hydroxyvitamin D <40 nmol/L, the overweight/obese odds ratio for males was 2.63 (95% CI 1.34 to 5.18). For 25-hydroxyvitamin D <50 nmol/L, overweight/obese odds ratios were 2.19 (95% CI 1.46 to 3.28) for males and 1.39 (95% CI 1.05 to 1.84) for females. Conclusions: This study confirms the inverse association between adiposity and serum concentrations of 25-hydroxyvitamin D in Canadian youth and the independent association of overweight/obesity to 25-hydroxyvitamin D level and vitamin D status after adjustment for other factors. [ABSTRACT FROM AUTHOR]

Background: Physical inactivity is a global public health concern. The relationship between dependent children in the home and parental physical activity has not been quantified using objective measures, nor has the relative association of the physical activity levels of mothers and fathers been examined. Purpose: To investigate the association of children of different ages in the home on two measures of parental physical activity: daily moderate-to-vigorous physical activity (MVPA) and likelihood of meeting the guideline of 150 minutes of MVPA per week accumulated in 10-minute bouts. Methods: Data were from the 2007–2009 Canadian Health Measures Survey (n=2315), and analyses were conducted between February and December 2011. MVPA was measured directly using accelerometry. Linear (minutes of MVPA) and logistic (meeting physical activity guidelines) regression models were performed to determine if the presence, number of children, or the age of the youngest child at home was associated with parental physical activity. All models were adjusted for parental age, marital status, household income, employment, and BMI. Results: Mothers whose youngest child was aged <6 years and fathers whose youngest was aged 6–11 years engaged in fewer minutes of daily MVPA than those without dependent children. Linear regression results identified that in comparison to those without children, women whose youngest child in the home was aged <6 years participated in 7.7 minutes less activity per day (p=0.007) whereas men engaged in 5.7 fewer minutes per day, or 54 and 40 minutes per week less, respectively. Similarly, logistic regression analyses indicated that both women and men were less likely to meet guidelines if their youngest child in the home was aged <6 years (OR=0.31, 95% CI=0.11, 0.87; OR=0.34, 95% CI=0.13, 0.93). Conclusions: The physical activity level of parents with young children present in the home was lower than that of those without children. Given the many physiologic, psychological, and social benefits of healthy active living, research efforts should continue to focus on strategies to encourage parents with young children to establish or re-engage in a physically active lifestyle, not only for their own health but to model healthy behavior for the next generation. [Copyright &y& Elsevier]