Vitamin A relative dose response test in undernourished children.

Abstract The relative dose response (RDR) has been proposed as a method for the estimation of body vitamin A stores and has been tested in children suffering from various grades of malnutrition. RDR was tested before and after 4–6 days of vitamin A administration either as a single massive oral dose of 200,000 i.u. or four smaller doses of 50,000 i.u. each. The results of the study indicated a positive RDR (> 14%) reflecting liver stores depletion in children whose serum levels of vitamin A were less than 0.35 μmol/l. Normal RDR (