Vitamin D3 seems more appropriate than D2 to sustain adequate levels of 25OHD: a pharmacokinetic approach.

OLIVERI B.; MASTAGLIA SR; BRITO GM; SEIJO M; KELLER GA; SOMOZA J; DIEZ RA; DI GIROLAMO G

EUROPEAN JOURNAL OF CLINICAL NUTRITION

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2015 vol. 69 p. 697 - 702

0954-3007

BACKGROUND/OBJECTIVES: The superiority of cholecalciferol (D3) over ergocalciferol (D2) in sustaining serum 25-hydroxy vitaminD (25OHD) levels is controversial. To compare D2 with D3 we performed a single-blind, placebo-controlled randomized trialspanning 11 weeks.SUBJECTS/METHODS: Healthy volunteers (n = 33, aged 33.4 ± 6 years) were divided into three groups (n = 11, each): D2, D3 andplacebo. Treatment started with a loading dose (100 000 IU) followed by 4800 IU/day (d) between d7 and d20 and follow-up untild77. Serum samples were obtained at baseline and at days 3, 7, 14, 21, 35, 49, 63 and 77.RESULTS: Baseline 25OHD values in the D2 group were lower than those in the D3 and placebo groups (Po0.01). Placebo 25OHDlevels never changed. As after the loading dose both D2 and D3 groups had reached similar 25OHD levels, we tested equivalence ofthe area under the concentration × time curve (AUC) between d7 and d77. The AUC was 28.6% higher for D3 compared with D2, andboth were higher with respect to placebo. At d77, D2 25OHD levels were higher than those at baseline, but similar to placebo; bothwere lower than D3 (Po0.04). According to raw data, the elimination half-life of 25OHD was 84 and 111 days under D2 and D3supplementation, respectively; after subtracting the placebo values, the corresponding figures were 33 and 82 days.CONCLUSIONS: D2 and D3 were equally effective in elevating 25OHD levels after a loading dose. In the long term, D3 seems moreappropriate for sustaining 25OHD, which could be relevant for classic and non-classic effects of vitamin D.