Aqueous solubilisation of vitamin D3 in normal man.

Jejunal aqueous solubilisation of vitamin D3 was assessed in eight normal subjects, after ingestion of a standard liquid test meal. Percentages and total concentrations of vitamin D3 in the aqueous phase were significantly higher in the first post-prandial 30 minutes than during the following two hours, as were bile salts, total lipids, and free fatty acids. As shown by partial correlation analysis, a statistically significant relationship was found between aqueous concentrations of free fatty acids and of vitamin D3 in the jejunal content during all the 2 1/2 hours of the study. From these data it is concluded that, in healthy man, vitamin D3 is solubilised in vivo in mixed micelles only, and is governed in the aqueous phase.