Bioavailability of Vitamin D Encapsulated in Casein Micelles, Compared to Its Bioavailability in the Milk-fat, or in a Synthetic Emulsifier Currently Used for Supplementation and Enrichment

The encapsulation within CM may improve bioavailability (BA) of vitamin D (VD), even in absence of fat. As a model the investigators have chosen nonfat yoghurt. The investigators will prepare yoghurts from 4 milks: (1) Skimmilk enriched with 50,000 IU/150gr VD encapsulated in CM2 ; (2) 3% fat milk wherein same dose of VD - dissolved in milk fat and homogenized into skimmilk; (3) 3% fat milk wherein VD, at same dose, will be in CM; (4) Placebo: unenriched skimmilk. 120 healthy adults aged 18-65 will randomized to 5 groups and receive 150 gr yoghurt. Blood will be drawn before ingestion and on days 1,7,14. 25(OH)D will be det. by CMIA. In vitro simulated digestion will be studied. Expected results: The BA of VD in CM would not be lower than in fat