EVIDENCE SUMMARY
A 2014 meta-analysis of 15 trials (quasi-random and RCT) with a total of 28,271 patients that compared the effect of vitamin D on fracture risk with placebo or no treatment, found no benefit for vitamin D supplementation (TABLE).1 Patients lived in community and nursing home settings and ranged in age from 50 to 85 years; 24% to 100% were female.
Only 3 trials required patients to have had a previous fracture. Exclusions included: diseases affecting bone metabolism, cognitive impairment, drugs affecting bone metabolism (bisphosphonates, selective estrogen receptor modulators, and corticosteroids), renal failure, hypercalcemia, nephrolithiasis, and decreased mobility (recent stroke recovery and Parkinson’s disease).
Formulations of vitamin D included cholecalciferol (D3) 400 to 2000 IU/d for 4 months to 5 years or 100,000 to 500,000 IU every 3 to 12 months for 1 to 5 years; calcifediol (25(OH)D3) 600 IU/d for 4 years; and ergocalciferol (D2) 400 IU/d for 2 years or 3000 to 300,000 IU every 3 to 12 months for 10 months to 3 years.
Vitamin D analogs generally have no benefit either
The same meta-analysis compared vitamin D analogs to placebo or no treatment (8 trials, quasi-random and RCT, 1743 patients) on the risk of fracture, again finding no benefit in all but one case. Included patients were mostly by referral to tertiary or university hospitals and outpatient community settings.
Most of the studies included only a small number of patients (about 200), with the largest study having 740 patients. The age range was 50 to 77 years, and 50% to 100% were female. Most of the trials required patients to have osteoporosis or vitamin D deficiency with a previous vertebral deformity on imaging. Study exclusions included osteomalacia, malabsorption, hyperparathyroidism, active kidney stones, history of hypercalciuria, cancer, incurable disease, dementia, severe chronic illness (renal or liver failure), recent stroke or fracture, and drugs that affect bone metabolism.