Acne treatment with oral zinc and vitamin A: effects on the serum levels of zinc and retinol binding protein (RBP).

The serum levels of zinc, vitamin A and retinol binding protein (RBP) were studied in 75 acne patients before and during oral treatment with zinc, vitamin A or placebo. In the zinc-treated patients an increase in the mean serum zinc level was seen after 2 weeks, when also the first clinical improvement occurred. After 4 weeks the zinc level had increased by about 30% and no further significant increase was observed during 3 months of treatment. In 33 healthy subjects there was an increase of 14% after 4 weeks of zinc therapy. Vitamin A and placebo induced no significant changes in the serum zinc status. Prior to therapy the serum levels of vitamin A and RBP were lower in the acne patients than in the controls. Zinc + vitamin A treatment raised the serum RBP value to normal after 4 weeks. In patients given vitamin A alone, a probable increase in RBP was achieved. Zinc and placebo treatment did not change the serum level of RBP.