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

Abstract

Background: 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. Objective: 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. Design: 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. Results: The serum retinol concentration and the MRDR value were 1.4 ± 0.5 μmol/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). Conclusions: 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 ≥ 5 mo. © 2006 American Society for Nutrition.