Circulating 25-hydroxyvitamin D levels and frailty status in older women

J Clin Endocrinol Metab. 2010 Dec;95(12):5266-73. doi: 10.1210/jc.2010-2317.

Abstract

Context: Vitamin D deficiency and frailty are common with aging, but the association between these conditions is uncertain.

Objective: To determine the association between 25-hydroxyvitamin D (25(OH)D) levels and prevalent and incident frailty status among older women.

Design: Cross-sectional and longitudinal analyses of a prospective cohort study.

Setting: Four U.S. centers.

Participants: 6307 women aged≥69 years.

Main outcome measures: Frailty status classified as robust, intermediate stage, or frail at baseline; and robust, intermediate stage, frail, or dead (all-cause mortality) at follow-up an average of 4.5 years later.

Results: At baseline, there was a U-shaped association between 25(OH)D level and odds of frailty with the lowest risk among women with levels 20.0-29.9 ng/ml (referent group). Compared with this group, the odds of frailty were higher among those with levels<15.0 ng/ml [multivariable odds ratio (MOR) 1.47, 95% confidence interval (CI), 1.19-1.82], those with levels 15.0-19.9 ng/ml (MOR 1.24, 95% CI 0.99-1.54), and those with levels≥30 ng/ml (MOR 1.32, 95% CI 1.06-1.63). Among 4551 nonfrail women at baseline, the odds of frailty/death (vs. robust/intermediate) at follow-up appeared higher among those with levels 15.0-19.9 ng/ml (MOR 1.21, 95% CI 0.99-1.49), but the CI overlapped 1.0. The odds of death (vs. robust/intermediate/frail at follow-up) was higher among those with levels<15.0 ng/ml (MOR 1.40, 95% CI 1.04-1.88) and those with levels 15.0-19.9 ng/ml (MOR 1.30, 95% CI 0.97-1.75), although the latter association did not quite reach significance.

Conclusion: Lower (<20 ng/ml) and higher (≥30 ng/ml) levels of 25(OH)D among older women were moderately associated with a higher odds of frailty at baseline. Among nonfrail women at baseline, lower levels (<20 ng/ml) were modestly associated with an increased risk of incident frailty or death at follow-up.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Alcohol Drinking
  • Calcium, Dietary
  • Cholecalciferol / blood
  • Cross-Sectional Studies
  • Ergocalciferols / blood
  • Female
  • Follow-Up Studies
  • Frail Elderly / statistics & numerical data*
  • Health Status
  • Humans
  • Longitudinal Studies
  • Odds Ratio
  • Prevalence
  • Risk Assessment
  • Smoking / epidemiology
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / complications

Substances

  • Calcium, Dietary
  • Ergocalciferols
  • Vitamin D
  • Cholecalciferol
  • 25-hydroxyvitamin D