25-Hydroxyvitamin D, cholesterol, and ultraviolet irradiation

Vitamin D deficiency may have implications for cardiovascular health. The purpose of this study was to determine the relationship of 25-hydroxyvitamin D (25[OH]D) to cholesterol and lipoprotein particles and to determine whether increasing 25(OH)D through ultraviolet (UV) irradiation impacted on these parameters in healthy young men and women. This was a randomized trial of 51 adults exposed to suberythemal doses of whole-body irradiation using UV lamps that emitted UV-A and UV-B radiation, compared with a control group, twice weekly for 12 weeks. 25-Hydroxyvitamin D, cholesterol, and lipoprotein subfractions were measured at baseline and after 12 weeks. There was a significant (P < .03) positive association between 25(OH)D and apolipoprotein A-I (Apo A-I) and lipoprotein A-I (Lp A-I). The ratio of low-density lipoprotein to high-density lipoprotein was significantly (P < or = .044) negatively correlated with 25(OH)D levels. The levels of 25(OH)D increased significantly in the treated compared with control group (P < .05). Overall, there were no significant differences between the treated and control groups in any lipoproteins or apolipoproteins after administration of UV irradiation. Subgroup analysis for Apo A-II confined to those with 25(OH)D insufficiency (25[OH]D