Differential effects of oral boluses of vitamin D2 versus vitamin D3 on vitamin D metabolism: a randomized controlled trial.
The Journal of clinical endocrinology and metabolism 2019
Martineau AR, Thummel KE, Wang Z, Jolliffe DA, Boucher BJ, Griffin SJ, Forouhi NG, Hitman GA
DOI : 10.1210/jc.2019-00207
PubMed ID : 31199458
PMCID : 0
Abstract
Vitamin D2 and vitamin D3 have been hypothesized to exert differential effects on vitamin D metabolism.
To compare the influence of administering vitamin D2 vs vitamin D3 on metabolism of vitamin D3.
We measured baseline and 4-month serum concentrations of vitamin D3, 25-hydroxyvitamin D3 (25[OH]D3), 25-hydroxyvitamin D2, 24R,25-dihydroxyvitamin D3 (24R,25[OH]2D3), 1α,25-dihydroxyvitamin D3 (1α,25[OH]2D3) and 4β,25-dihydroxyvitamin D3 (4β,25[OH]2D3) in 52 adults randomized to receive a total of four oral bolus doses of 2.5 mg vitamin D2 (n=28) or vitamin D3 (n=24) over four months. Metabolite-to-parent compound ratios were calculated to estimate hydroxylase activity. Pairwise before-versus-after comparisons were made to evaluate effects of vitamin D2 and vitamin D3 on metabolism of vitamin D. Mean post-supplementation metabolite-to-parent ratios were then compared between groups.
Vitamin D2 was less effective than vitamin D3 in elevating total 25(OH)D concentration. Vitamin D2 suppressed mean 4-month serum concentrations of 25(OH)D3, 24R,25(OH)2D3, 1α,25(OH)2D3 and 4β,25(OH)2D3 and mean ratios of 25(OH)D3-to-D3 and 1α,25(OH)2D3-to-25(OH)D3, while increasing the mean ratio of 24R,25(OH)2D3-to-25(OH)D3. Vitamin D3 increased mean 4-month serum concentrations of 25(OH)D3, 24R,25(OH)2D3, 1α,25(OH)2D3 and 4β,25(OH)2D3, and the mean ratio of 24R,25(OH)2D3-to-25(OH)D3. Participants receiving vitamin D2 had lower mean post-supplementation ratios of 25(OH)D3-to-vitamin D3 and 1α,25(OH)2D3-to-25(OH)D3 than those receiving vitamin D3. Mean post-supplementation ratios of 24R,25(OH)2D3-to-25(OH)D3 and 4β,25(OH)2D3-to-25(OH)D3 did not differ between groups.
Bolus-dose vitamin D2 is less effective than bolus-dose vitamin D3 in elevating total serum 25(OH)D concentration. Administration of vitamin D2 reduces 25-hydroxylation of vitamin D3 and 1-alpha hydroxylation of 25(OH)D3, while increasing 24R-hydroxylation of 25(OH)D3.