The vitamin D status of many Canadians is insufficient

One quarter of Canadians are not meeting recommended intakes for vitamin D despite fortified foods, says a new study.

In the observational study, vitamin D concentrations in blood samples from 5,306 people aged between six and 79 were measured (1). In addition, supplement use was quantified by interviewing the participants. The study results showed that 25% of the participants did not meet the Recommended Dietary Allowance ( RDA) for vitamin D (50 nanomoles 25-hydroxyvitamin D per liter) and 5% were vitamin D deficient (less than 30 nmol/L). In non-supplement users, the prevalence of concentrations below 50 nmol/L in winter was 37.2% overall and was 60.7% in non-whites. Supplement users had significantly higher vitamin D concentrations than did nonusers, and no seasonal differences were found.

The researchers concluded that current food choices alone are insufficient to ensure optimal blood levels of vitamin D for many Canadians, especially in winter. Currently, only milk and margarine are subject to mandatory fortification with vitamin D in Canada, indicating a potential to expand food fortification. Experts commented that dietary supplements can bridge the vitamin gap, but the most realistic approach to boosting the nation’s intake of vitamin D is for food manufacturers to increase the dose of vitamin D per serving.

Recent research indicated that inadequate levels of vitamin D may be causing about 37,000 premature deaths in Canada and costing the country billions of dollars. Vitamin D deficiency in adults is reported to precipitate or exacerbate osteoporosis, muscle weakness, fractures, common cancers, autoimmune diseases, infectious diseases and cardiovascular diseases.

1. Whiting S. J. et al. The vitamin D status of Canadians relative to the 2011 Dietary Reference Intakes: an examination in children and adults with and without supplement use. American Journal of Clinical Nutrition. 2011.