Examining the effects of increased vitamin D fortification on dietary inadequacy in Canada

Despite mandatory fortification of milk and margarine, most Canadians have inadequate vitamin D intake and consequently poor vitamin D status, especially in the winter. Increasing vitamin D fortification is one possible strategy to address this inadequacy. The purpose of our study was to examine the modelled effect of increased vitamin D fortification on the prevalence of inadequacy and the percentage of intakes greater than the Tolerable Upper Intake Level (UL) using different fortification scenarios.

Dietary intakes (24-h recall) from the 2004 Canadian Community Health Survey 2.2 (n=34,381) were used to model increased vitamin D levels in milk and the addition of vitamin D to cheese and yogurt at various levels to meet label claims of an "excellent source" based on the recommended dietary intakes. The Software for Intake Distribution Evaluation was used to estimate the prevalence of inadequacy and intakes >UL.

Fortification of milk, yogurt and cheese at 6.75 μg (270 IU)/serving led to more than doubling of vitamin D intakes across all sex/age groups and a drop in the prevalence of dietary inadequacy from >80% to <50% in all groups. Furthermore, no intakes approached the UL under any fortification scenario in any sex/age group.

There is a pressing need to improve vitamin D status among Canadians. Increasing vitamin D fortification of dairy products, consistent with their positioning in Canada's Food Guide, can lead to increased intake without a risk of excess. This is a population-wide public health strategy that should be given consideration in Canada.