Dietary intake of vitamin D in a northern Canadian Dené First Nation community

Abstract

Background: Increased awareness of the wide spectrum of activity of vitamin D has focused interest on its role in the health of Canada's Aboriginal peoples, who bear a high burden of both infectious and chronic disease. Cutaneous vitamin D synthesis is limited at northern latitudes, and the transition from nutrient-dense traditional to nutrient-poor market foods has left many Canadian Aboriginal populations food insecure and nutritionally vulnerable.

Objective: The study was undertaken to determine the level of dietary vitamin D in a northern Canadian Aboriginal (Dené) community and to determine the primary food sources of vitamin D.

Design: Cross-sectional study.

Methods: Dietary vitamin D intakes of 46 adult Dené men and women were assessed using a food frequency questionnaire and compared across age, gender, season and body mass index. The adequacy of dietary vitamin D intake was assessed using the 2007 Adequate Intake (AI) and the 2011 Recommended Dietary Allowance (RDA) values for Dietary Reference Intake (DRI).

Results: Mean daily vitamin D intake was 271.4 IU in winter and 298.3 IU in summer. Forty percent and 47.8% of participants met the vitamin D 1997 AI values in winter and summer, respectively; this dropped to 11.1 and 13.0% in winter and summer using 2011 RDA values. Supplements, milk, and local fish were positively associated with adequate vitamin D intake. Milk and local fish were the major dietary sources of vitamin D.

Conclusions: Dietary intake of vitamin D in the study population was low. Only 2 food sources, fluid milk and fish, provided the majority of dietary vitamin D. Addressing low vitamin D intake in this population requires action aimed at food insecurity present in northern Aboriginal populations.

Keywords: Aboriginal; First Nations; diet; food security; indigenous; nutrition; vitamin D.

Fig. 1

Daily mean intake of vitamin D, in winter and summer, according to source.

Fig. 2

Seasonal percent of oral vitamin D intake by source for participants who took vitamin D supplements (A) and for those who did not (B). *FFQs obtained from 45 participants in winter and 46 in summer.