Effects of vitamin D3 and calcium supplementation on serum levels of tocopherols, retinol, and specific vitamin D metabolites.
Study Goal
The researchers aimed to determine whether vitamin D₃ and calcium supplementation, alone or in combination, alters levels of lipid-soluble micronutrients, including tocopherols and vitamin D metabolites.
Results Summary
The study found that vitamin D₃ plus calcium supplementation led to a 14% decrease in serum α-tocopherol and a 19% decrease in γ-tocopherol, though the latter was not statistically significant. No significant effects were observed for leptin or retinol levels.
Population
85 subjects in a randomized, double-blind, placebo-controlled clinical trial.
Effective Dosage
2 g calcium (frequency not specified).
Duration
6 months.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
vitamin D(3) supplementation | increase | Serum 25[OH]-vitamin D(3) levels | subjects from a randomized, double-blind, placebo-controlled clinical trial | 55% | increased | #1 |
vitamin D(3) plus calcium | increase | Serum 25[OH]-vitamin D(3) levels | subjects from a randomized, double-blind, placebo-controlled clinical trial | 48% | increased | #2 |
vitamin D(3) supplementation | decrease | 25[OH]-vitamin D(2) levels | subjects from a randomized, double-blind, placebo-controlled clinical trial | 48% | were lower | #3 |
vitamin D(3) plus calcium | decrease | 25[OH]-vitamin D(2) levels | subjects from a randomized, double-blind, placebo-controlled clinical trial | 21% | were lower | #4 |
vitamin D(3) plus calcium treatment | decrease | serum α-tocopherol | subjects from a randomized, double-blind, placebo-controlled clinical trial | 14% | decreased | #5 |
vitamin D(3) plus calcium treatment | decrease | γT | subjects from a randomized, double-blind, placebo-controlled clinical trial | 19% lower | similar changes | #6 |
D(3) supplementation | no change | leptin levels | subjects from a randomized, double-blind, placebo-controlled clinical trial | no significant change | No significant effects | #7 |
D(3) supplementation | no change | retinol levels | subjects from a randomized, double-blind, placebo-controlled clinical trial | no significant change | No significant effects | #8 |
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]-vitamin D(3) levels increased 55% (P < 0.0001) and 48% (P = 0.0005), whereas 25[OH]-vitamin D(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 α-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.