Canadian Vitamin D deficiency – May 2011

The vitamin D status of Canadians relative to the 2011 Dietary Reference Intakes: an examination in children and adults with and without supplement use.

Am J Clin Nutr. 2011 May 18.
Whiting SJ, Langlois KA, Vatanparast H, Greene-Finestone LS.
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada.

BACKGROUND:
The 2011 Dietary Reference Intakes (DRIs) for vitamin D use 25-hydroxyvitamin D 25(OH)D concentrations to define vitamin D deficiency (<30 nmol/L), the Estimated Average Requirement (40 nmol/L), and the Recommended Dietary Allowance (RDA; 50 nmol/L). The Canadian population has not yet been assessed according to these recommendations.

OBJECTIVE:
We determined the prevalence of meeting DRI recommendations and the role of vitamin D supplement use among Canadians aged 6-79 y.

DESIGN:
Plasma 25(OH)D from a representative sample of Canadians in the Canadian Health Measures Survey-Cycle 1 (n = 5306) were used. Supplement use was assessed by household interview. Concentrations of 25(OH)D were compared in supplement users and nonusers by season and race.

RESULTS:
Overall, 5.4%, 12.7%, and 25.7% of the participants had 25(OH)D concentrations below the 30-, 40-, and 50-nmol/L cutoffs, respectively. In white Canadians, plasma 25(OH)D concentrations ranged from an undetectable percentage with concentrations <30 nmol/L in summer to 24.5% with concentrations <50 nmol/L in winter;

the corresponding values ranged from 12.5% to 53.1% in nonwhite Canadians.

Supplement users had significantly higher 25(OH)D concentrations than did nonusers, and no seasonal differences were found. In nonsupplement users, the prevalence of 25(OH)D concentrations <50 nmol/L in winter was 37.2% overall and was 60.7% in nonwhites.

CONCLUSIONS:
One-quarter of Canadians did not meet the RDA, but the use of vitamin D supplements contributed to a better 25(OH)D status.

Nonwhite Canadians had the highest risk of not achieving DRI recommendations.

More than one-third of Canadians not using supplements did not meet the RDA in winter.
This suggests that current food choices alone are insufficient to maintain 25(OH)D concentrations of 50 nmol/L in many Canadians, especially in winter.

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In ng/ml

• < 12 ng 5%
• < 16 ng 13%
• < 20 ng 26%
  • non supplement whites in winter 37%
  • non-supplement nonwhites in winter 61%

Portions of 2 charts in the paper

See also VitaminDWiki

• All items in category Canada 51 items
• Another paper on Canadian vitamin D April 2011
• 90 percent of Canadian youth less than 30 ng vitamin D – Oct 2010
• 27 percent of Canadian women had less than 30 ng of vitamin D – Sept 2010
• 75 percent of Canadians less than 30 ng vitamin D in winter – Aug 2010
• Inuit preschoolers were very vitamin D deficient – Aug 2010
  • dark skin, no longer getting vitamin D from sea mammals
• Overview Dark Skin and Vitamin D
• Hypothesis – Black births are much riskier due to lack of vitamin D – April 2011
• Dark Skinned youths and vitamin D in Southern Canada - Dissertation 2011
• Proposed National Vitamin D Day in Canada – Feb 2012
• Many groups feel that the minimum vitamin D level is 30 ng, not 20 ng

CLICK HERE for chart details