Supplemental vitamin D does not reduce the risk of fracture in older adults (VITAL)

Référence

LeBoff MS, Chou SH, Ratliff KA, et al. Supplemental vitamin D and incident fractures in midlife and older adults. N Engl J Med 2022;387(4):299-309.

Sommaire

This study randomized 25,871 men 50 years and older and women 55 years and older in a 2 x 2 factorial design to receive 2000 IU vitamin D per day or placebo, and 1000 mg omega-3 fatty acid per day or placebo. Patients were not selected on the basis of their fracture risk or vitamin D levels; participants with a history of cancer, cardiovascular disease, or hypercalcemia were excluded. The primary goal of the VITAL trial was to evaluate the effect of these supplements on cancer and cardiovascular outcomes. Fractures were assessed based on patient self-report in an annual survey and confirmed by medical record review. The mean age of participants was 57 years, 51% were women, and 20% were Black. Approximately 25% of patients had a baseline vitamin D level of less than 24 ng/mL and 1.5% had a value of less than 12 ng/mL. About 42% in each group were taking supplemental vitamin D, which they agreed to limit to no more than 800 mg per day during the study. There were a total of 1991 fractures in 1551 patients, with no difference in total, nonvertebral, hip, or "osteoporotic" fractures (hip + wrist + humerus + spine). The authors did a series of prespecified subgroup analyses, and found no benefit in patients who were taking none of their own supplemental vitamin D or calcium in the placebo group, and in patients with a previous fragility fracture, The mean 25-hydroxyvitamin D level was 30.7 ng/mL at baseline, and there was no difference in fracture rates in different quartiles of vitamin D levels, including patients with vitamin D levels of less than 24.0 ng/mL (hazard ratio [HR] 1.04; 95% CI 0.80 - 1.36) and of less than 12 ng/mL (HR 1.03; 0.36 - 2.95). There were no differences among groups with regard to renal stones or episodes of hypercalcemia or other adverse events.