Effect of Providing Multiple Micronutrients in Powder through Primary Healthcare on Anemia in Young Brazilian Children: A Multicentre Pragmatic Controlled Trial

Abstract

Background: Multiple micronutrients in powder (MNP) are recommended by WHO to prevent anemia in young children. However, evidences for its effectiveness in different populations and improvements in other outcomes (e.g. linear growth and vitamin A deficiency) are scarce.

Methods: A multicentre pragmatic controlled trial was carried out in primary health centres. At study baseline, a control group (CG) of children aged 10- to 14 months (n = 521) was recruited in the routine healthcare for assessing anemia, anthropometric and micronutrient status. At the same time, an intervention group (IG) of infants aged 6- to 8 months (n = 462) was recruited to receive MNP daily in complementary feeding over a period of 60 days. Both study groups were compared when the IG infants reached the age of the CG children at enrolment.

Results: In CG, the prevalence of anemia [hemoglobin (Hb) < 110 g/L], iron deficiency (ID, plasma ferritin < 12 μg/L or TfR > 8.3 mg/L), and vitamin A deficiency (VAD, serum retinol < 0.70μmol/L) were 23.1%, 37.4%, and 17.4%, respectively. Four to six months after enrolment, when the IG participants had the same age of the controls at the time of testing, the prevalence of anemia, ID and VAD in IG were 14.3%, 30.1% and 7.9%, respectively. Adjusting for city, health centre, maternal education, and age, IG children had a lower likelihood of anemia and VAD [Prevalence Ratio (95% CI) = 0.63 (0.45, 0.88) and 0.45 (0.29, 0.69), respectively] when compared with CG children. The adjusted mean distributions of Hb and length-for-age Z-scores improved by 2 SE in the IG compared to CG children.

Conclusions: MNP effectively reduced anemia and improved growth and micronutrient status among young Brazilian children.

Trial registration: Registro Brasileiro de Ensaios Clinicos RBR-5ktv6b.

Fig 1. Flow of participants in the ENFAC study.

CG, control group; ENFAC, Estudo Nacional de Fortificação caseira da Alimentação Complementar; IG, intervention group.

Fig 2. Relative frequency of hemoglobin (Hb in A) and Z-scores for length-for-age (HAZ in B) values adjusted for primary health center, city, child age and maternal schooling in multilevel linear regression analysis by ENFAC study groups.

CG, control group; ENFAC, Estudo Nacional de Fortificação caseira da Alimentação Complementar; HAZ, lenght/height-for-age Z-score; Hb, hemoglobina; IG, intervention group.

Fig 3. Frequency (%) of iron deficiency (A), iron deficiency anemia (B) and vitamin A deficiency (C) stratified by inflammation status using combined plasma values of CRP and AGP according to ENFAC study groups.

Reference, CRP ≤ 5mg/L and AGP ≤ 1g/L, n = 302 (A and B) or 296 (C) in CG, and n = 275 (A and B) or 274 (C) in IG; Chronic, CRP ≤ 5mg/L and AGP> 1g/L, n = 83 (A and B) or 84 (C) in CG, and n = 59 (A, B or C) in IG; Acute, CRP >5 and AGP> 1g/L mg/L, n = 68 (A and B) or 65 (C) in CG, and n = 30 (A and B) or 27 (C) in IG. Totals differ from the total number of study children due to missing values for biochemical indicators. The symbol * indicates significant differences for the IG compared with CG (Pearson χ² test). AGP, α-1-acid glycoprotein; CG, control group; CRP, C-reactive protein; ENFAC, Estudo Nacional de Fortificação caseira da Alimentação Complementar; IG, intervention group.