Vitamin D insufficiency and health outcomes over 5 y in older women.
BACKGROUND
Vitamin D insufficiency was shown to be associated with adverse musculoskeletal and nonskeletal outcomes in numerous observational studies. However, some studies did not control for confounding factors such as age or seasonal variation of 25-hydroxyvitamin D [25(OH)D].


OBJECTIVE
We sought to determine the effect of vitamin D status on health outcomes.


METHODS
Healthy community-dwelling women (n = 1471) with a mean age of 74 y were followed in a 5-y trial of calcium supplementation. 25(OH)D was measured at baseline in all women. Skeletal and nonskeletal outcomes were evaluated according to seasonally adjusted vitamin D status at baseline.


RESULTS
Fifty percent of women had a seasonally adjusted 25(OH)D concentration <50 nmol/L. These women were significantly older, heavier, and less physically active and had more comorbidities than women with a seasonally adjusted 25(OH)D concentration > or =50 nmol/L. Women with a seasonally adjusted 25(OH)D concentration <50 nmol/L had an increased incidence of stroke and cardiovascular events that did not persist after adjustment for between-group differences in age or comorbidities. Women with a seasonally adjusted 25(OH)D concentration <50 nmol/L were not at increased risk of adverse consequences for any musculoskeletal outcome, including fracture, falls, bone density, or grip strength or any nonskeletal outcomes, including death, myocardial infarction, cancer, heart failure, diabetes, or adverse changes in blood pressure, weight, body composition, cholesterol, or glucose.


CONCLUSIONS
Vitamin D insufficiency is more common in older, frailer women. Community-dwelling older women with a seasonally adjusted 25(OH)D concentration <50 nmol/L were not at risk of adverse outcomes over 5 y after control for comorbidities. Randomized placebo-controlled trials are needed to determine whether vitamin D supplementation in individuals with vitamin D insufficiency influences health outcomes. This trial was registered at www.anzctr.org.au as ACTRN 012605000242628.
Bolland
Mark J
MJ
Department of Medicine, University of Auckland, Auckland, New Zealand. m.bolland@auckland.ac.nz
Bacon
Catherine J
CJ
Horne
Anne M
AM
Mason
Barbara H
BH
Ames
Ruth W
RW
Wang
Tom Km
TK
Grey
Andrew B
AB
Gamble
Greg D
GD
Reid
Ian R
IR
D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D015519:Bone Density; D002118:Calcium / Q000097:blood / Q000494:pharmacology*; D002762:Cholecalciferol / Q000008:administration & dosage / Q000494:pharmacology; D019587:Dietary Supplements; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology / Q000517:prevention & control; D018737:Hand Strength; D006304:Health Status; D006801:Humans; D006887:Hydroxycholecalciferols / Q000172:deficiency; D015994:Incidence; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D010710:Phosphates / Q000097:blood; D017698:Postmenopause; D014808:Vitamin D Deficiency / Q000503:physiopathology*
D006887:Hydroxycholecalciferols; D008055:Lipids; D010710:Phosphates; D002762:Cholecalciferol; D002118:Calcium