SCIENCE CORNER
New Science
December 2022
Micronutrient deficiencies among preschool-aged children and women of reproductive age worldwide: a pooled analysis of individual-level data from population-representative surveys. Scientific Reports 11: 3344.
Stevens, G.A., Beal, T., Mbuya, M.N.N., Luo, H.Q., Neufeld, L.M. 2022.
Summary by Dobermann, A.
Micronutrient deficiencies compromise immune systems, hinder child growth and development, and affect human potential worldwide. Micronutrient deficiencies (vitamins and mineral) have often been reported to affect an estimated 2 billion people. This estimate is important for drawing attention to the problem and could be used to track global progress. However, the estimate is from three decades ago and is based on anaemia prevalence only, and not on measured micronutrient deficiencies.
This study provides updated global and regional estimates of micronutrient deficiencies using individual-level biomarker data for multiple micronutrients, based on data collected between 2003 and 2019 in 22 countries. The authors estimate that there are 372 million preschool-aged children (aged 6–59 months) with deficiency in at least one of three micronutrients (iron, zinc, vitamin A). High prevalences of Zn deficiency in children were, for example, found in Pakistan (40%), Vietnam (56%), Cameroon (57%), Malawi (61%) and Cambodia (67%). Additionally, 1.2 billion non-pregnant women of reproductive age (aged 15–49 years) were found to have one or more micronutrient deficiencies (iron, zinc, folate) worldwide. In summary, the results suggest that over half of preschool-aged children and two-thirds of non-pregnant women of reproductive age worldwide have micronutrient deficiencies.
Such estimates are always associated with great uncertainties and other micronutrients such as selenium or iodine were not included in this analysis. Overall, this new evidence indicates, however, that little progress has been made in alleviating such hidden hunger problems. Plant nutrition, through enrichment of fertilizers with micronutrients or foliar application can play a significant role in mitigating micronutrient deficiencies in humans. For example, in a recent feeding trial zinc-fortified wheat significantly increased the dietary zinc intake and blood plasma zinc levels of rural women Pakistan.