A Randomised, Cross-Over Study to Estimate the Influence of Food on the 25-Hydroxyvitamin D3 Serum Level after Vitamin D3 Supplementation

Vitamin D3 is known to be liposoluble and its release could be a factor limiting the rate of absorption. It was presumed that the presence of fat could favor absorption of vitamin D3. However, as bioavailability is related not only to the active molecules but also to the formulations and excipients used, the optimization of the pharmaceutical form of vitamin D3 is also important. The objective of this study was to evaluate if there is a food effect on absorption when a high dose of vitamin D3 is completely solubilized in an oily solution. In the present cross-over study, 88 subjects were randomized and received a single dose of 50,000 IU of vitamin D3 in fasting state or with a standardized high-fat breakfast. Assessment of serum concentrations of 25 hydroxyvitamin D3 (25(OH)D3) was performed three, five, seven, 14, 30 and 60 days after supplementation. In fed and fast conditions, the 25(OH)D3 serum concentrations were significantly higher than the baseline value three days after administration and remained significantly higher during the first month. No significant difference between fasting vs. fed conditions was observed. It is therefore concluded that the vitamin D3 absorption from an oily solution was not influenced by the presence or absence of a meal.