Preparation of 25-hydroxycholecalciferol

What it is. 25-hydroxycholecalciferol is a nutritional additive from the vitamin group (3a), a hydroxylated metabolite of vitamin D3. Its precursor, 5,7,24-cholestatrienol, is produced by fermentation with Saccharomyces cerevisiae CBS 146008, then chemically converted and photochemically transformed into 25-hydroxycholecalciferol. The additive is presented in solid form, with a maximum active substance content of 1.25 %.

What it is for. It is used as a source of active vitamin D, a hydroxylated form more readily absorbed than cholecalciferol, to support phosphocalcium metabolism, bone mineralisation and growth performance. It is intended for poultry (broiler chickens and turkeys, other poultry), pigs, bovines and ovines, as well as salmonids and other fish. It is incorporated into feed as a premixture, partially or fully replacing vitamin D3 according to formulation needs.

Points to watch. The maximum content of the combination of 25-hydroxycholecalciferol and cholecalciferol per kg of complete feed is regulated and varies by species (for example ≤ 0.125 mg for broiler chickens and turkeys, ≤ 0.080 mg for other poultry, ≤ 1.500 mg for salmonids, ≤ 0.075 mg for other fish). Instructions must specify storage conditions and stability to heat treatment. The additive's purity must meet set criteria (25-hydroxycholecalciferol > 94 %, other sterol derivatives ≤ 1 % each, erythrosine < 5 mg/kg).