Objective: Our objective was to investigate whether vitamin D or calcium supplementation affects mortality, vascular disease, and cancer in older people.
Design and Setting: The study included long-term follow-up of participants in a two by two factorial, randomized controlled trial from 21 orthopedic centers in the United Kingdom.
Participants: Participants were 5292 people (85% women) aged at least 70 yr with previous low-trauma fracture.
Interventions: Participants were randomly allocated to daily vitamin D3 (800 IU), calcium (1000 mg), both, or placebo for 24–62 months, with a follow-up of 3 yr after intervention.
Main Outcome Measures: All-cause mortality, vascular disease mortality, cancer mortality, and cancer incidence were evaluated.
Results: In intention-to-treat analyses, mortality [hazard ratio (HR) = 0.93; 95% confidence interval (CI) = 0.85–1.02], vascular disease mortality (HR = 0.91; 95% CI = 0.79–1.05), cancer mortality (HR = 0.85; 95% CI = 0.68–1.06), and cancer incidence (HR = 1.07; 95% CI = 0.92–1.25) did not differ significantly between participants allocated vitamin D and those not. All-cause mortality (HR = 1.03; 95% CI = 0.94–1.13), vascular disease mortality (HR = 1.07; 95% CI = 0.92–1.24), cancer mortality (HR = 1.13; 95% CI = 0.91–1.40), and cancer incidence (HR = 1.06; 95% CI = 0.91–1.23) also did not differ significantly between participants allocated calcium and those not. In a post hoc statistical analysis adjusting for compliance, thus with fewer participants, trends for reduced mortality with vitamin D and increased mortality with calcium were accentuated, although all results remain nonsignificant.
Conclusions: Daily vitamin D or calcium supplementation did not affect mortality, vascular disease, cancer mortality, or cancer incidence.