Micronutrient needs in children with severe wasting and/or nutritional oedema

Micronutrients are vital for health, especially in malnourished children, yet data on deficiencies in severely malnourished children is limited. Therapeutic foods like F-75, F-100, and ready-to-use-therapeutic food are intended to address these deficiencies, but our understanding of their micronutrient content is based more on the views of experts than on robust evidence.

The review’s authors used micronutrient content data for F-75, F100, and ready-to-use-therapeutic food on Nutriset’s website to estimate the average daily amount of each micronutrient that a child with severe acute malnutrition would consume across the different phases of treatment. This was then compared to dietary reference intakes to assess adequacy. The authors also undertook a comprehensive literature review. 

Detailed findings for each micronutrient are reported, including an overview of the deficiency, specific considerations for severe wasting and/or nutritional oedema, and research opportunities. This level of detail is beyond the scope of this summary but can be explored in the original paper. Overall, the review uncovers deficiencies and major gaps in research for almost all micronutrients in children with severe wasting and nutritional oedema. The authors emphasise that the complex functions of each micronutrient in the body may play a crucial role in determining outcomes. Micronutrient status is often different in children presenting with nutritional oedema compared to those with severe wasting, requiring a differing approach. 

The paper identifies some challenges of the review: dietary reference intakes are based on healthy rather than sick populations; there is variability in micronutrient status between individual children and between geographic contexts; and there is variability in the use of biochemical markers, levels used to define deficiency, and the impact of disease states/malnutrition on these biomarkers of micronutrient status. 

In particular the authors highlight three micronutrient deficiencies that need urgent attention: thiamine, iron, and vitamin D. Children at risk of severe wasting are at high risk of thiamine deficiency due to poor intake, poor absorption capacity, and enteropathy. Current intake of thiamine from therapeutic products is inadequate to prevent and treat refeeding syndrome. Iron deficiency anaemia is very prevalent in children with severe wasting and may persist in 25% of them post-treatment. There may be benefits to improving iron content in F-100 and bioavailability in ready-to-use therapeutic food, for example, but these approaches need to be balanced with potential harmful effects of increased iron. Although there are limited studies of the prevalence of vitamin D deficiency in severe wasting, its persistence post-treatment is common. High-dose supplementation can enhance growth and reduce developmental delay. 

Future studies should prioritise research in each of these three areas. Thereafter, additional research should explore the effects of universal or targeted micronutrient supplementation in therapeutic foods, paving the way for evidence-based improvements in policy and clinical practice.