Effects of vitamin D 3 and calcium supplementation on serum levels of tocopherols, retinol, and specific vitamin D metabolites

摘要

γ-Tocopherol (γT) protects against DNA-damaging effects of nitrogen oxides, yet its physiologic regulation in vivo is unknown. Observational studies indicate inverse associations of 25[OH]-vitamin D with γT and leptin. To determine whether vitamin D 3 supplementation alters levels of lipid-soluble micronutrients, serum samples (N = 85 subjects) from a randomized, double-blind, placebo-controlled clinical trial of vitamin D 3 (800 IU) and calcium (2 g), alone and in combination, were analyzed for lipid micronutrients and specific vitamin D metabolites at baseline and after 6 mo of supplementation. Serum 25[OH]-vitaminD 3 levels increased 55% (P 0.0001) and 48% (P = 0.0005), whereas 25[OH]-vitaminD 2 levels were lower by 48% (P = 0.26) and 21% (P = 0.36) in the vitamin D 3 and vitamin D 3 plus calcium groups, respectively. At baseline, γT levels were inversely associated with 25[OH]D (r = -0.31, P = 0.004). With vitamin D 3 plus calcium treatment, serum -tocopherol decreased 14% (P = 0.04), whereas similar changes in γT (19% lower, P = 0.14) were observed. No significant effects were observed for D 3 supplementation on leptin or retinol levels. These results are consistent with the hypothesis that vitamin D 3± calcium affects serum tocopherol and 25[OH]D 2 levels; however, studies using larger, more homogeneous populations are warranted.