The Effects of Vitamin D Supplementation and 25-Hydroxyvitamin D Levels on the Risk of Myocardial Infarction and Mortality.

Objective The aim of the study was to examine the effects of the vitamin D (Vit-D) treatment and nontreatment on Vit-D-deficient patients without a prior history of myocardial infarction (MI). Materials and methods This was a retrospective, observational, nested case-control study of patients (N = 20 025) with low 25-hydroxyvitamin D ([25-OH]D) levels ( Results Among the cohort of 20 025 patients, the risk of MI was significantly lower in Group C than in Group B (hazard ratio [HR] 0.65, 95% CI 0.49-0.85, P = .002) and Group A (HR 0.73, 95% CI 0.55-0.96), P = .02). There was no difference in the risk of MI between Group B and Group A (HR 1.14, 95% CI 0.91-1.42, P = 0.24). Compared with Group A, both Group B (HR 0.59, 95% CI 0.54-0.63, P Conclusions In patients with Vit-D deficiency and no prior history of MI, treatment to the (25-OH)D level of >20 ng/mL and >30 ng/mL was associated with a significantly lower risk of all-cause mortality. The lower risk of MI was observed only in individuals maintaining (25-OH)D levels ≥30 ng/mL.