Statin Use and 25-Hydroxyvitamin D Blood Level Response to Vitamin D Treatment of Older Adults.

OBJECTIVES: To determine whether statin use alters response of 25-hydroxyvitamin D (25(OH)D) level to vitamin D treatment. DESIGN: Pooled analysis. SETTING: Three double-blind randomized controlled trials that tested different doses of vitamin D. PARTICIPANTS: Participants of three trials (N = 646; mean age 76.3 ± 8.4, 65% female). MEASUREMENTS: In all three trials, 25(OH)D status and statin use were assessed repeatedly over time (baseline, 6 and 12 months). Repeated-measures analysis was used to compare 25(OH)D response to vitamin D treatment at baseline and 6 and 12 months of statin users and nonusers, controlling for age, sex, body mass index, Charlson Comorbidity Index, vitamin D dose, trial, and season. RESULTS: At baseline, 17.5% were statin users, and 65% were vitamin D deficient (25(OH)D < 20 ng/mL). Baseline 25(OH)D levels did not differ significantly between groups at baseline (18.8 for statin users, 17.2 ng/mL for nonusers, P = .07), but according to the longitudinal analyses, the total increase over 12 months in 25(OH)D concentration was significantly lower in statin users (13.1 ng/L) than nonusers (15.9 ng/mL; 21.4% difference; P = .009). CONCLUSION: Of persons aged 60 and older at high risk of vitamin D deficiency, statin users had a 21.4% smaller increase in 25(OH)D serum concentrations over time than nonusers, independent of vitamin D dose and other covariates.