... monohydroxyvi-tamin D3.Because cyclodextrin provides an artificial means of holding vitamin D3 in solution, we also examined the metabolism of vitamin D3 incorporated into the membrane of phospholipid ... identification of the majordihydroxyvitamin D3 product as 20,23-dihydroxyvitamin D3, rather than20,22-dihydroxyvitamin D3, explains why there is no cleavage of the vita-min D3 side chain, unlike the ... determining the substrates from which they arose by the action of P450scc, as well as the products that they gave rise to.This revealed both the major and minor pathways for the metabolism of vitamin...