Bioavailability of vitamin D3 in non-oily capsules: the role of formulated compounds and implications for intermittent replacement

Abstract

Objective: To evaluate the bioavailability of vitamin D in capsules as compared with oily drops in nuns living in a closed community with very low sun exposure. Methods: A randomized, 2 x 2 crossover, open clinical trial was conducted, with 18 nuns aged between 20 and 75 years. Samples were collected in the fasting state and at 4, 8, 12 and 24 hours following the administration of capsules and oily drops (both containing vitamin D3 66,000 UI plus vitamin A 13,200 UI) to determine serum 25 hydroxivitamin D concentrations (25OHD), at baseline and 90 days after. The evaluation was based on the maximum concentration (C max ) and area under the curve (AUC 0-24 ). Results: The capsule formulation presented C max and AUC 0-24 , 5.78% and 0.76%, respectively, greater than the oily drops formulation. Conclusion: Both formulations were within the limits for a bioequivalence study, namely C-90% for C max and AUC 0-24 , and the drugs were considered bioequivalent. Arq Bras Endocrinol Metab. 2010;54(2):239-43 Keywords Bioavailability; vitamin D; pharmacokinetics RESUMO Objetivo: Avaliar a biodisponibilidade da vitamina D3 em cápsulas, comparando com gotas oleosas, em religiosas que vivem em comunidade fechada com baixa exposição solar. Méto-dos: Ensaio clínico aberto, aleatório e cruzado 2 x 2, com 18 religiosas (20-75 anos de idade). As amostras foram coletadas em jejum e 4, 8, 12 e 24 horas após a administração de cápsulas e de gotas oleosas (ambos contendo 66.000 UI de vitamina D3 e 13.200 UI de vitamina A) para dosagem da 25 hidroxivitamina D (25OHD), em data base e 90 dias após. A avaliação baseouse nos resultados da concentração máxima (C máx ) da 25OHD e da área sob a curva (ASC 0-24 ). Resultados: A análise descritiva desses parâmetros demonstrou que a cápsula apresentou C máx e ASC 0-24 de 5,78% e 0,76% a mais que as gotas oleosas, respectivamente. Conclusão: Ambas as formulações encontravam-se dentro dos limites de aceitação em estudo de bioequivalência IC-90% para C máx e ASC ( 0-24 ), daí as drogas serem consideradas bioequivalentes. Arq Bras Endocrinol Metab. 2010;54(2):239-43

The Role of Vitamin D Oral Supplementation in Insulin Resistance in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

“…In healthy subjects, vitamin D in an oil vehicle produced a greater 25(OH)D response than vitamin D in a powder or an ethanol vehicle [ 43 ]. On the other hand, Coelho et al indicated that vitamin D 3 entering the bloodstream is not affected by capsule formulation [ 44 ]. Since there have been limited studies that have compared the effect of the vehicle substance on vitamin D bioavailability, future studies should examine bioavailability across different vehicle substances, such as oil, lactose powder, and ethanol [ 43 ].…”

Vitamin D Bioavailability: State of the Art

“…It is concluded that although limited studies are available, vitamin D in an oil vehicle is more bioavailable than when incorporated in a powder-based vehicle (cellulose or lactose) or in ethanol. However, a recent clinical trial has concluded that vitamin D is more bioavailable from a lactose capsule than from an oily drop formulation (Coelho et al, 2010).…”

Effect of High- versus Low-Fat Meal on Serum 25-Hydroxyvitamin D Levels after a Single Oral Dose of Vitamin D: A Single-Blind, Parallel, Randomized Trial

“…Although there are several studies about the effect of different ways to supply vitamin D in its serum levels [5–9] or in serum 25(OH)D levels [10–14], only a few of these studies describe the amount of fat ingested with vitamin D [7, 9, 11]. Therefore, the aim of this study was to compare serum 25(OH)D levels after the oral intake of cholecalciferol with a high- or low-fat meal in young adults.…”