Vitamin D status of older adults of diverse ancestry living in the greater Toronto area

Jaime K Ginter,S Krithika,Esteban J Parra,Agnes Gozdzik,Susan Whiting,Heather Hanwell

doi:10.1186/1471-2318-13-66

Abstract

BackgroundPhysiological and lifestyle factors put older adults at an increased risk of vitamin D insufficiency and resulting negative health outcomes. Here we explore the vitamin D status in a sample of community dwelling older adults of diverse ancestry living in the Greater Toronto area (GTA).MethodsTwo hundred and twenty-four (224) adults over 60 years of age were recruited from the Square One Older Adult Centre, in Mississauga, Ontario. Circulating 25-hydroxyvitamin D (25(OH)D) concentrations were measured from dried blood spot cards. Dietary and supplemental intakes of vitamin D were assessed via questionnaires. Skin pigmentation was assessed quantitatively by measuring melanin levels using a reflectometer.ResultsThe mean 25(OH)D concentration in the total sample was 82.4 nmol/L. There were no statistically significant differences in serum 25(OH)D concentrations, supplemental or dietary vitamin D intakes between the three major ancestral groups (East Asians, Europeans and South Asians). Females had significantly higher 25(OH)D concentrations than males (84.5 nmol/L vs. 72.2 nmol/L, p = 0.012). The proportion of participants with 25(OH)D concentrations below 50 nmol/L and 75 nmol/L were 12.1%, and 38.8%, respectively. The mean daily supplemental intake of vitamin D was 917 IU/day. Vitamin D intake from supplements was the major factor determining 25(OH)D concentrations (p < 0.001).ConclusionsMean concentration of 25(OH)D in a sample of older adults of diverse ancestry living in the GTA exceeded 80 nmol/L, and there were no significant differences in 25(OH)D levels between ancestral groups. These results sharply contrast with our recent study focused on young adults of diverse ancestry living in the same geographic area, in which we found substantially lower 25(OH)D concentrations (mean 39.5 nmol/L), low supplemental vitamin D intake (114 IU/day), and significant differences in 25(OH)D levels between ancestral groups. High daily intake of supplemental vitamin D in this sample of older adults likely accounts for such disparate findings with respect to the young adult sample.

Highlights

Physiological and lifestyle factors put older adults at an increased risk of vitamin D insufficiency and resulting negative health outcomes
We wanted to contrast our findings with previous studies of 25(OH)D levels in older adults [22,24,25,26], and a previous study of young adults of diverse ancestry living in the Greater Toronto Area (GTA) [23]
Here, we report the vitamin D status in a sample of community dwelling, active older adults of diverse ancestry living in the Greater Toronto Area (GTA)

Summary

Introduction

Physiological and lifestyle factors put older adults at an increased risk of vitamin D insufficiency and resulting negative health outcomes. We explore the vitamin D status in a sample of community dwelling older adults of diverse ancestry living in the Greater Toronto area (GTA). Cutaneous vitamin D synthesis is less efficient in older individuals due to the age-associated. Information about the vitamin D status of older adult Canadians of diverse ancestry is limited. Detailed descriptions of ancestry are often not reported in vitamin D studies, including national surveys in Canada [22] and older persons of diverse ethnicities have been found not to be included in meaningful numbers in studies exploring vitamin D status [15]. The aim of this study was to explore the wintertime vitamin D status of an understudied segment of the Canadian population: older adults of diverse ancestry. We wanted to contrast our findings with previous studies of 25(OH)D levels in older adults [22,24,25,26], and a previous study of young adults of diverse ancestry living in the Greater Toronto Area (GTA) [23]

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