Vitamin A and iron status of children before and after treatment of uncomplicated severe acute malnutrition

Abstract

Background & aims: Treatment of children with uncomplicated severe acute malnutrition (SAM) is based on ready-to-use therapeutic foods (RUTF) and aims for quick regain of lost body tissues while providing sufficient micronutrients to restore diminished body stores. Little evidence exists on the success of the treatment to establish normal micronutrient status. We aimed to assess the changes in vitamin A and iron status of children treated for SAM with RUTF, and explore the effect of a reduced RUTF dose.

Methods: We collected blood samples from children 6-59 months old with SAM included in a randomised trial at admission to and discharge from treatment and analysed haemoglobin (Hb) and serum concentrations of retinol binding protein (RBP), ferritin (SF), soluble transferrin receptor (sTfR), C-reactive protein (CRP) and α1-acid glycoprotein (AGP). SF, sTfR and RBP were adjusted for inflammation (CRP and AGP) prior to analysis using internal regression coefficients. Vitamin A deficiency (VAD) was defined as RBP < 0.7 μmol/l, anaemia as Hb < 110 g/l, storage iron deficiency (sID) as SF < 12 μg/l, tissue iron deficiency (tID) as sTfR > 8.3 mg/l and iron deficiency anaemia (IDA) as both anaemia and sID. Linear and logistic mixed models were fitted including research team and study site as random effects and adjusting for sex, age and outcome at admission.

Results: Children included in the study (n = 801) were on average 13 months of age at admission to treatment and the median treatment duration was 56 days [IQR: 35; 91] in both arms. Vitamin A and iron status markers did not differ between trial arms at admission or at discharge. Only Hb was 1.7 g/l lower (95% CI -0.3, 3.7; p = 0.088) in the reduced dose arm compared to the standard dose, at recovery. Mean concentrations of all biomarkers improved from admission to discharge: Hb increased by 12% or 11.6 g/l (95% CI 10.2, 13.0), RBP increased by 13% or 0.12 μmol/l (95% CI 0.09, 0.15), SF increased by 36% or 4.4 μg/l (95% CI 3.1, 5.7) and sTfR decreased by 16% or 1.5 mg/l (95% CI 1.0, 1.9). However, at discharge, micronutrient deficiencies were still common, as 9% had VAD, 55% had anaemia, 35% had sID, 41% had tID and 21% had IDA.

Conclusion: Reduced dose of RUTF did not result in poorer vitamin A and iron status of children. Only haemoglobin seemed slightly lower at recovery among children treated with the reduced dose. While improvement was observed, the vitamin A and iron status remained sub-optimal among children treated successfully for SAM with RUTF. There is a need to reconsider RUTF fortification levels or test other potential strategies in order to fully restore the micronutrient status of children treated for SAM.

Keywords: Children; Iron; Micronutrient; Ready-to-use therapeutic food; Severe acute malnutrition; Vitamin A.