Dietary reference intakes for vitamin D based on the revised 2010 dietary guidelines are not being met by children in Alberta, Canada

Abstract

Canadian children have been shown to be not meeting the revised (2010) dietary recommended intake (DRI) for vitamin D through diet alone. However, no study has evaluated whether diet and supplementation together are supporting Canadian children in meeting the DRIs for vitamin D intake. This study assessed the adequacy of vitamin D intake through diet and supplements among Albertan children and the determinants of meeting dietary guidelines. 2686 grade 5 students aged 10 to 11 years in Alberta, Canada were surveyed. We hypothesized that less than 50% of children would meet the DRI. Vitamin D intake from diet and supplements was assessed using a food frequency questionnaire. The adequacy of vitamin D intake was estimated using the Estimated Average Requirement (EAR) of 400 IU (International Units) and Recommended Dietary Allowance (RDA) of 600 IU. Random effect multiple logistic regression was used to identify correlates of meeting DRIs. Forty five percent of children met the EAR and 22% met the RDA for vitamin D. When vitamin D intake from diet alone was considered, only 16% and 2% met the EAR and RDA, respectively. Parental education, household income and physical activity were positively correlated with meeting DRIs, and students attending metropolitan area schools were more likely to meet the EAR than students attending rural area schools (OR = 1.28; P = .043). The majority of children did not meet the DRI for vitamin D. Health promotion strategies aiming to improve the vitamin D status of Albertan children are necessary given the importance of vitamin D for children's health and development.

Keywords: Alberta; Canada; Determinants; Dietary intake; Dietary supplementation; Vitamin D.