Associations Between Serum 25-Hydroxyvitamin D Concentrations and Multiple Health Conditions, Physical Performance Measures, Disability, and All-cause Mortality

The Concord Health and Ageing in Men Project

Vasant Hirani, PhD; Robert G. Cumming, PhD; Vasi Naganathan, PhD; Fiona Blyth, PhD; David G. Le Couteur, PhD; David J. Handelsman, PhD; Louise M. Waite, PhD; Markus J. Seibel, PhD

Disclosures

J Am Geriatr Soc. 2014;62(3):417-425. 

In This Article

Abstract and Introduction

Abstract

Objectives: To explore associations between serum 25-hydroxyvitamin D (25(OH)D) levels and a wide range of health conditions, physical performance measures, disability, and mortality in a large epidemiological study to identify an optimum range for 25(OH)D concentrations.

Design: Cross-sectional study, with additional prospective data on falls and mortality.

Setting: Concord Health and Ageing in Men Project, Sydney, Australia.

Participants: Community-dwelling men aged 70 and older (N = 1,659).

Measurements: Serum 25(OH)D levels, general health status, self-reported diseases, physical performance measures, disability (activities of daily living and instrumental activities of daily living) and falls.

Results: Fair, poor, and very poor health; self-reported diabetes mellitus; hyperglycemia; depression; muscle weakness; poor balance; and all-cause mortality were all associated with serum 25(OH)D levels less than 50 nmol/L, even after adjustment for confounding. The findings also suggest that, in older men, for a wide range of health conditions, physical performance measures, disability, falls, and mortality, the optimum range of 25(OH)D is between 50.0 and 74.9 nmol/L, with no additional benefit for 25(OH)D levels of 75.0 nmol/L or greater.

Conclusion: Programs aimed at achieving an optimum range of serum 25(OH)D at levels between 50.0 and 74.9 nmol/L may have overall health benefits and such levels are adequate for older men.

Introduction

Inadequate vitamin levels D (25-hydroxyvitamin D (25(OH)D) concentrations <50 nmol/L) are a widespread and emerging major public health problem globally.[1,2,3] The importance of vitamin D for bone health is well known, but there is increasing interest in the link between vitamin D deficiency and a wide range of noncommunicable diseases.[4,5]

There is no clear consensus on optimal 25(OH)D levels for overall health.[3] The Institute of Medicine and others have proposed a serum 25(OH)D level of less than 50.0 nmol/L as the definition of vitamin D insufficiency,[4,6] whereas other evidence suggests that levels of 75.0 nmol/L or greater are desirable.[7,8] A recent position statement[3] states that 25(OH)D levels of 50 nmol/L or greater at the end of winter and 50 to 80 nmol/L at the end of summer are adequate. Most of the recommendations for optimal 25(OH)D levels have been derived from studies that have bone-related outcomes. The target levels for other health outcomes may not be the same.

A recent study has found associations between 25(OH)D levels of less than 50 nmol/L and clinical outcomes such as hip fracture, myocardial infarction, incident cancer, and mortality in individuals aged 65 and older.[9] Another study of adults aged 25 and older (mean age 51) who participated in the Australian Diabetes, Obesity and Lifestyle Study[10] reported on 25(OH)D levels and associations with diabetes mellitus and found that participants in the third and fourth quartiles of serum 25(OH)D (median 70 and 93 nmol/L) had 57% and 44% less risk, respectively, of developing type 2 diabetes mellitus over 5 years than those in the lowest quartile (median 40 nmol/L).[11]

No other population-based study in older community-living men has examined associations between 25(OH)D levels and a broad range of health conditions, physical performance measures, disability, and all-cause mortality. The aims of this study were therefore to assess the associations between serum 25(OH)D concentrations and these health outcomes in a large group of community-living men aged 70 and older and to identify an optimum range of 25(OH)D for these outcomes in this population.

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