Metabolism of orally administered ergosterol and 7-dehydrocholesterol in rats and lack of evidence for their vitamin D biological activity.

Metabolism of orally administered ergosterol (Erg) and 7-dehydrocholesterol (7-DHC) in rats and their vitamin D biological activity were investigated. Most of orally administered Erg and 7-DHC were excreted in feces and the remaining sterols were absorbed through intestine. The absorbed sterols were not transported in skin as the intact forms but metabolized into brassicasterol and cholesterol, respectively, within 25 h. Neither increment of intestinal calcium absorption nor plasma calcium concentrations were observed by oral administration of Erg and 7-DHC to vitamin D-deficient rats. Therefore, we have concluded that orally administered Erg and 7-DHC have no vitamin D biological activity.