Prevalence of vitamin D insufficiency among healthy school-age Cree children

Background: First Nations children are at higher risk for vitamin D deficiency and rickets. Objective: To assess the prevalence of vitamin D deficiency and the correlations between fat mass, parathyroid hormone and dietary habits with serum vitamin D level in a random sample of Cree children eight to 14 years of age. Methods: Serum 25-hydroxyvitamin D (25[OH] D) levels and additional information regarding anthropometrics and dietary habits were obtained from participants in two Cree communities. Vitamin D deficiency and insufficiency was defined as serum 25(OH) D levels < 30 nmol/L and < 50 nmol/L, respectively. Proportions to estimate the vitamin D status were weighted to account for the complex sampling design, and Pearson's correlation coefficients were used to estimate the associations of milk and fish intake, parathyroid hormone and fat mass with serum 25(OH) D levels. Results: Data from 52 healthy Cree children (mean [+/- SD] age 11.1 +/- 2.0 years; 27 boys) were included in the analyses. The median serum 25(OH) D level was 52.4 nmol/L (range 22.1 nmol/L to 102.7 nmol/L). Forty-three percent (95% CI 29% to 58%) and 81% (95% CI 70% to 92%) of Cree children had vitamin D levels < 50 nmol/L and < 75 nmol/L, respectively. Vitamin D intake was positively associated with serum 25(OH) D levels. Obese children had lower vitamin D levels; however, the difference was nonsignificant. Conclusion: There may be a substantial proportion of Cree children who are vitamin D deficient. Increasing age, lower dietary vitamin D intake and, possibly, higher body mass index were associated with decreased vitamin D levels; however, causality cannot be inferred.