Abstract 12918: Vitamin D Supplementation Did Not Have an Effect on Serum Total or Subclasses of High-Density Lipoprotein-Cholesterol; A Pilot Study

Introduction: Both prevalent and incident CVD are negatively associated with 25-hydroxyvitamin D (25[OH] D) levels but the existence of a causal mechanism has yet to be determined. Vitamin D (D) supplementation may increase total HDL-c or one of the HDL subclasses; HDL2 and HDL3 and decrease CVD. The effect of D supplementation with HMG-CoA reductase inhibitor use on HDL-c, HDL2, and HDL3 also remains unclear. Hypotheses: We assessed the following two hypotheses; 1) HDL-c, HDL2, or HDL3 levels will increase with D supplementation for 12 weeks versus placebo and 2) HDL-c, HDL2, or HDL3 levels will increase with D supplementation for 12 weeks with HMG-CoA reductase inhibitor use versus without HMG-CoA reductase inhibitor use. Methods: Serum sample data, including 25(OH) D, HDL-c, HDL2, and HDL3 levels, from a randomized double-blinded placebo-controlled trial conducted between 2008 and 2012 were secondarily analyzed. Statistical analyses included Pearson correlation and Repeated-Measures ANOVA. Results: Hypothesis #1; of the 59 participants (mean age=56.0 years), 39 had a deficient (< 20 ng/mL) baseline 25(OH) D level. Hypothesis #2; of the 40 participants (mean age=56.5 years) 23 had a deficient (< 20 ng/mL) baseline 25(OH) D level. Pearson correlation showed 12-week 25(OH) D levels were moderately positively correlated with 12-week HDL-c (0.337, p ≤ 0.05) and 12-week HDL3 (0.356 p ≤ 0.05) levels but not at baseline. Hypotheses #1 and #2; baseline and 12-week levels for HDL-c, HDL2, and HDL3 were moderately to strongly positively correlated with female gender and moderately to strongly negatively correlated with BMI. Some participants did not achieve sufficient 25(OH) D levels. Repeated-Measures ANOVA with one between-subjects factor; group, and one within-subjects factor; time, showed no statistically significant difference in the mean change in HDL-c, HDL2 or HDL3 for D supplementation versus placebo or for D supplementation with versus without HMG-CoA reductase inhibitor use. Conclusions: Future studies may provide more informative results if they include; more participants, deficient 25(OH) D level as an inclusion criteria, and continued D supplementation until sufficiency is attained versus discontinuation after a pre-specified time period.