Vitamin D status in healthy free-living elderly men and women living in Quebec, Canada

Abstract

Objective: To assess vitamin D status in relation to age, sex, season, adiposity, physical activity level, and supplement use in healthy elderly Canadians living in Québec.

Design: Cross-sectional survey.

Setting: Data for 405 healthy free-living elderly Quebécers aged between 68 and 82 years with no major health problems were examined.

Subjects: Men and women in age groups of 68-72, 73-77, and 78-82 years, in 2 seasons, participating in the NuAge cohort.

Measurements: serum 25(OH)D assessed by radioimmunoassay (RIA), weight, height, smoking status, disease status, education, perception of income, Physical Activity Scale for the Elderly (PASE) questionnaire, and vitamin D supplement consumption.

Results: The prevalence of vitamin D deficiency (25(OH)D <37.5 nmol/L) was 12.6% and 5.7% for men in winter and summer, and 8.7% and 1.9% for women, respectively. Over 50% of the participants had 25(OH)D concentrations <75 nmol/L. Correlates of vitamin D status by multiple regression analysis indicated that the vitamin D level in summer was 13.8 nmol/L higher for participants measured in winter and 17.2 nmol/L higher for those using supplements. Age, sex, body mass index, and physical activity were not associated with 25(OH)D concentration.

Conclusion: Prevalence of vitamin D deficiency is low in healthy elderly men and women, especially in summer, but over 50% of the participants had suboptimal vitamin D concentrations. Vitamin D supplement consumption increased 25(OH)D concentrations substantially, particularly in the winter months, and should be encouraged.