Bolzetta F, et al. - This longitudinal study was designed to examine whether vitamin D supplementation was correlated with a lower risk of frailty in older people. During 8 years of follow-up in a large cohort of North American people, low-dose vitamin D supplementation was not associated with any decreased risk of frailty.

Methods

• For 8 years, the physicians followed 4,421 individuals at high risk or having knee osteoarthritis free from frailty at baseline (mean age: 61.3, females = 58.0%).
• They captured details regarding vitamin D supplementation by asking whether the participant took vitamin D during the previous year, at least once per month.
• They defined frailty using the Study of Osteoporotic Fracture (SOF) index as the presence of at least 2 of the following criteria:
  • Weight loss ≥ 5% between baseline and any subsequent follow-up visit;
  • Inability to do 5 chair stands;
  • Low energy level according to the SOF definition.
• They performed multivariable Cox's regression analyses which calculated hazard ratios (HRs) with 95% confidence intervals (CIs).

Results

• With a mean dose of 384 ± 157 IU per day, 69.7% took vitamin D supplements in the previous year at baseline.
• The physicians found no difference in the incidence of frailty by vitamin D supplementation status at baseline, even after adjusting for 13 baseline confounders (HR = 0.95; 95% CI: 0.72–1.25), during the 8-year follow-up.
• They obtained similar results using the propensity score (HR = 0.95; 95% CI: 0.71–1.25) or age- and sex-matched controls (HR = 1.00; 95% CI: 0.75–1.33).