Effect of antenatal and infant micronutrient supplementation on middle childhood and early adolescent development outcomes in Tanzania

Abstract

Background: There is growing evidence that nutritional interventions in the first 1,000 days of life may influence long-term health and development outcomes. Few studies have examined the effect of maternal and infant micronutrient supplementation on development outcomes in sub-Saharan Africa. Methods: We conducted a follow-up study of two randomized trials of antenatal and infant micronutrient supplementation conducted in Dar es Salaam, Tanzania. We assessed the effect of maternal multiple micronutrient (MMN) supplementation in pregnancy on development of children at 11–14 years of age. We also examined the effect of infant zinc and MMN supplementation on development at 6–8 years of age. We use generalized linear models to assess standardized mean differences (SMDs) in general intelligence, executive function and mental health scores. Results: We followed-up 446 children whose mothers were enrolled in the maternal MMN supplementation trial and 365 children who were enrolled in the infant zinc and MMN supplementation trial. We found no effect of maternal MMN supplementation on general intelligence (SMD: −0.03; 95% CI: −0.15, 0.09), executive function (SMD: 0.00; 95% CI: −0.11, 0.11) and mental health scores (SMD: 0.06; 95% CI: −0.10, 0.22). We also found no effect of either infant zinc or MMN supplementation on any of the three development domains (p-values >0.05). Conclusions: We found that antenatal MMN supplementation and infant zinc and MMN supplementation did not have a large effect on development outcomes in middle childhood and early adolescence in Tanzania.

Antenatal multiple micronutrient supplementation: where are the long‐term benefits?

“…Similarly, at 9–12 years of age, in a subsample of 10.5% of children (2879/27,356) alive at 12 weeks, procedural memory was improved by 0.11 SD (95% CI = 0.01, 0.20), but there was no difference in any of the six other developmental areas examined . Such largely null results were replicated in other cognitive follow‐up studies from China, Tanzania, and four separate studies from Bangladesh and Nepal …”

Does zinc with and without iron co-supplementation have effect on motor and mental development of children? A systematic review and meta-analysis

“…Four studies assessed the long term effect of zinc supplementation with and without iron on child development in 6-9 year old children. All of them were supplemented before 36 months old [36,46,48,52]. These studies showed that zinc supplementation with and without iron does not have any long term effect on child mental and motor development in school age.…”

“…Eleven studies only supplemented children with zinc alone [32, 33, 35, 38-41, 44, 45, 50, 54] and four studies co-supplemented them with zinc and iron [34,36,37,49]. Ten trials had three parallel arms that one arm received zinc and iron; another arm received iron; and the third arm received zinc alone [22,23,42,43,[46][47][48][51][52][53].…”

“…With regard to child development assessment tools, nine studies assessed the child development by BSID second edition [22,32,34,35,37,39,41,43,54], one study evaluated the development by BSID third edition [44], and 15 studies used other developmental assessment tools [23,33,36,38,40,42,[45][46][47][48][49][50][51][52][53]. Furthermore four studies were RCTs that supplemented children before the age of 5 years old and assessed their development in school age [36,46,48,52]. The rest of the studies evaluated the development before the age of five.…”

“…Supplementary File 1 shows the characteristics of all included studies more comprehensively. [23, 33-39, 42, 46, 47, 50, 51], nine articles had low risk [40,41,43,45,48,49,[52][53][54] and three studies had high risk of bias [22,32,44]. In addition, 18 articles had low risk of bias [23, 33-37, 40, 41, 43-48, 50-52, 54], seven studies had unclear risk of bias [22,32,38,39,42,49,53] and no study had high risk of bias in allocation concealment domain.…”