Serum levels of vitamin D metabolites in isotretinoin-treated acne patients

Abstract

Serum levels of vitamin D metabolites were determined in 11 patients treated for cystic acne with a four-month course of isotretinoin (Roaccutane®). The levels were measured before treatment and after two months of medication. We found a significant fall in the level of 1,25-dihydroxyvitamin D (p < 0.01) and a significant increase in the molar ratio of 24,25-dihydroxyvitamin D to 25-hydroxvitamin D (p < 0.05). No significant changes were found for the vitamin D metabolites 25-hydroxyvitamin D or 24,25-dihydroxy-vitamin D, for serum calcium, phosphorus, alkaline phosphatase or parathyroid hormone. Our data indicate early changes in the metabolism of vitamin D in patients on retinoid treatment.