Evaluation of vitamin A supplementation regimens in Ghanaian postpartum mothers with the use of the modified-relative-dose-response test

Abstract

Vitamin A deficiency is an important public health problem in many developing countries. Women of childbearing age and children are documented as the most affected groups. The objective was to determine the length of time mothers are protected postpartum against vitamin A depletion after receiving either 400,000 IU vitamin A in 2 divided doses or 200,000 IU as a single dose plus a placebo 24 h apart. Mothers (n = 168) were recruited by trained fieldworkers 7-10 d after delivery. Modified-relative-dose-response (MRDR) tests were performed at baseline in 167 women, and vitamin A was administered within 6 wk after delivery. The women were randomly assigned to 2 main treatment groups, and each treatment group was divided into 3 follow-up subgroups. Each subgroup was invited back once at month 1, 3, or 5 for a second MRDR test. The serum retinol concentration and the MRDR value were 1.4 +/- 0.5 micromol/L and 0.048 +/- 0.037, respectively, at baseline. A significant improvement in vitamin A status occurred after vitamin A treatment as assessed by the MRDR test (P < 0.0001). Serum retinol concentrations were not different after vitamin A treatment (P = 0.87). The mothers had marginally depleted liver reserves of vitamin A at baseline on the basis of MRDR test results. Liver reserves of vitamin A significantly improved in both treatment groups, and the improvement was maintained for >or= 5 mo.