The addition of preformed vitamin A, but not orange‐fleshed sweet potato with high beta‐carotene content, to rice‐based meals reduces zinc absorption in vitamin A‐depleted Bangladeshi women

Abstract

The effect of vitamin A on zinc absorption in humans is unknown. We examined the independent effects of vitamin A or beta‐carotene intake and vitamin A status on zinc absorption in vitamin A‐depleted women (plasma retinol <1.05 mmol/L). Zinc absorption from meals with and without vitamin A added and containing high or low beta‐carotene was assessed using stable isotopes before and after 60 days of controlled feeding with white‐fleshed sweet potato (WFSP) + oil capsule, orange‐fleshed sweet potato (OFSP) + oil capsule, or WFSP + vitamin A capsule. Fractional zinc absorption from meals with vitamin A added was lower than zinc absorption from meals with no vitamin A [29.8 ± 6.6 vs. 37.2 ± 9.0 %, p < 0.0001], both before and after the 60‐day controlled feeding period. No difference in zinc absorption from diets containing WFSP or OFSP was found at either time point, and there was no effect of treatment group after the intervention. The addition of vitamin A to rice‐based meals reduces zinc absorption while absorption is not affected by consumption of OFSP with high beta‐carotene content. Intake of OFSP or vitamin A supplements for 60 days does not affect zinc absorption following intervention in vitamin A‐depleted Bangladeshi women. Funding provided by the HarvestPlus Project and the International Nutrition Foundation Fellowship Program.