Food fortification improves the intake of all fortified nutrients, but fails to meet the estimated dietary requirements for vitamins A and B6, riboflavin and zinc, in lactating South African women

Abstract

Objective: To investigate the impact of fortification by comparing food records and selected biochemical indicators of nutritional status pre- and post-fortification.

Design: Mean intake from 24 h recalls (n 142) was compared with the Estimated Average Requirement (EAR) to determine the proportion with inadequate intake. In a subsample (n 34), diet and serum retinol, folate, ferritin and Zn were compared pre- and post-fortification for fortified nutrients vitamin A, thiamin, riboflavin, niacin, folic acid, Fe and Zn.

Setting: South Africa.

Subjects: Breast-feeding women (ninety-four HIV-infected, forty eight HIV-uninfected) measured at ~6, 14, 24 weeks, and 9 and 12 months postpartum.

Results: Pre-fortification, >80 % of women did not meet the EAR for vitamins A, C, D, thiamin, riboflavin, niacin, B6, B12 and folate and minerals Zn, iodine and Ca. Dietary intake post-fortification increased for all fortified nutrients. In post-fortification food records, >70 % did not meet the EAR for Zn and vitamins A, riboflavin and B6. Serum folate and Zn increased significantly post-fortification (P < 0.001 for both), with no change in ferritin and a reduction in retinol. Post-fortification marginal/deficient folate status was reduced (73.5 % pre v. 3.0 % post; P < 0.001), as was Zn deficiency (26.5 % pre v. 5.9 % post; P < 0.05). Pre- and post-fortification, >93 % were retinol replete. There was no change in Fe deficiency (16.7 % pre v. 19.4 % post; P = 0.728).

Conclusions: Micronutrient intake improved with fortification, but >70 % of lactating women did not meet the EAR for Zn, vitamins A, riboflavin and B6. Although 100 % exceeded the EAR for Fe after fortification, Fe status did not improve.