Kellie Langlois

The vitamin D status of Canadians relative to the 2011 Dietary Reference Intakes: an examination in children and adults with and without supplement use

BACKGROUND The 2011 Dietary Reference Intakes (DRIs) for vitamin D use 25-hydroxyvitamin D [25(OH)D] concentrations to define vitamin D deficiency (<30 nmol/L), the Estimated Average Requirement (40 nmol/L), and the Recommended Dietary Allowance (RDA; 50 nmol/L). The Canadian population has not yet been assessed according to these recommendations. OBJECTIVE We determined the prevalence of meeting DRI recommendations and the role of vitamin D supplement use among Canadians aged 6-79 y. DESIGN Plasma 25(OH)D from a representative sample of Canadians in the Canadian Health Measures Survey-Cycle 1 (n = 5306) were used. Supplement use was assessed by household interview. Concentrations of 25(OH)D were compared in supplement users and nonusers by season and race. RESULTS Overall, 5.4%, 12.7%, and 25.7% of the participants had 25(OH)D concentrations below the 30-, 40-, and 50-nmol/L cutoffs, respectively. In white Canadians, plasma 25(OH)D concentrations ranged from an undetectable percentage with concentrations <30 nmol/L in summer to 24.5% with concentrations <50 nmol/L in winter; the corresponding values ranged from 12.5% to 53.1% in nonwhite Canadians. Supplement users had significantly higher 25(OH)D concentrations than did nonusers, and no seasonal differences were found. In nonsupplement users, the prevalence of 25(OH)D concentrations <50 nmol/L in winter was 37.2% overall and was 60.7% in nonwhites. CONCLUSIONS One-quarter of Canadians did not meet the RDA, but the use of vitamin D supplements contributed to a better 25(OH)D status. Nonwhite Canadians had the highest risk of not achieving DRI recommendations. More than one-third of Canadians not using supplements did not meet the RDA in winter. This suggests that current food choices alone are insufficient to maintain 25(OH)D concentrations of 50 nmol/L in many Canadians, especially in winter.

Young Children and Parental Physical Activity Levels Findings from the Canadian Health Measures Survey

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.

Hunger among Inuit children in Canada

Background and objectives Inuit populations may be at increased risk for experiencing poor nutrition or hunger due to limited access and availability to food. The prevalence and correlates of parental perceptions of hunger among a nationally representative sample of Inuit children in Canada have not yet been reported. Design Data are from the 2006 Aboriginal Childrens Survey (ACS). Sociodemographic information, dietary behaviours and hunger status were parent-reported via a household interview for Inuit children aged 2–5 years (n=1,234). Prevalence of hunger was calculated among Inuit children by sociodemographic factors and by dietary behaviours. In addition, a multivariate logistic regression model was conducted to determine factors associated with parental perception of ever experiencing hunger. Results The prevalence of Inuit children in Canada aged 2–5 years ever experiencing hunger was 24.4%. Children who were reported to have experienced hunger consumed milk and milk products (p<0.001); fish, eggs and meat (p<0.05); fruits (p<0.001); and vegetables (p<0.001) significantly less often than never-hungry children. Fast food and processed foods, soft drinks and juice, and salty snacks, sweets and desserts were consumed as often as never-hungry children (all p>0.05). The majority (81%) of Inuit parents/guardians of ever-hungry children sought help from family or friends. Factors associated with an increased likelihood of experiencing hunger include sociodemographic characteristics (such as income and household size), living in an Inuit region and living in a community with cultural activities. Conclusion About 1 in 4 Inuit children were reported by their parents to have experienced hunger, and hunger was associated with region, sociodemographic and community factors. Future research could further examine the impact of ever experiencing hunger on the health status of Inuit children and their families in Canada.

Overweight and obesity are associated with lower vitamin D status in Canadian children and adolescents

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.