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Isotopic measurement of iron requirements in sub-Saharan African children
Cornelia Speich1, Gary M Brittenham2, Colin I Cercamondi1
1Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland.
Insights
Iron requirements estimated by WHO/FAO are adequate for healthy African children. However, iron-deficient children need more bioavailable iron to overcome their deficiency.
Area of Science:
- Nutritional science
- Pediatric health
- Public health in Africa
Background:
- Iron deficiency prevention is critical for African children's health.
- Current iron requirement estimates by WHO/FAO are based on limited data from adults and healthy children.
Purpose of the Study:
- To quantify iron absorption, loss, and balance in rural African children aged 5-7 years.
- To assess the adequacy of current iron recommendations in this population.
Main Methods:
- A 2-year observational study in Malawian children (n=48) using stable iron isotopes.
- Direct measurement of long-term iron absorption and iron loss.
Main Results:
- Iron-deficient children (36%) weighed more than iron-sufficient children.
- Iron losses were comparable to WHO/FAO estimates and did not differ between groups.
- Iron absorption in iron-sufficient children met WHO/FAO requirements, but iron-deficient children did not increase absorption sufficiently due to low dietary iron bioavailability.
Conclusions:
- WHO/FAO iron requirements appear adequate for healthy, iron-sufficient children in rural Malawi.
- Iron-deficient children in this population require increased intake of bioavailable iron to correct their status.
Background:
Prevention of iron deficiency in African children is a public health priority. Current WHO/FAO estimations of iron requirements are derived from factorial estimates based on healthy, iron-sufficient "model" children using data derived mainly from adults.
Objectives:
In this study, we aimed to quantify iron absorption, loss, and balance in apparently healthy 5- to 7-y-old children living in rural Africa.
Methods:
We directly measured long-term iron absorption and iron loss in a 2-y observational study in Malawian children (n = 48) using a novel stable iron isotope method.
Results:
Of the 36 children with height-for-age and weight-for-age z scores ≥-2, 13 (36%) were iron deficient (soluble transferrin receptor >8.3 mg/L) and 23 were iron sufficient. Iron-deficient children weighed more than iron-sufficient children [mean difference (95% CI): +2.1 (1.4, 2.7) kg; P = 0.01]. Mean iron losses did not differ significantly between iron-deficient and iron-sufficient children and were comparable to WHO/FAO median estimates of 19 µg/(d × kg). In iron-sufficient children, median (95% CI) dietary iron absorption was 32 (28, 34) µg/(d × kg), comparable to WHO/FAO-estimated median requirements of 32 µg/(d × kg). In iron-deficient children, absorption of 28 (25, 30) µg/(d × kg) was not increased to correct their iron deficit, likely because of a lack of bioavailable dietary iron. Twelve children (25%) were undernourished (underweight, stunted, or both).
Conclusions:
Our results suggest that WHO/FAO iron requirements are adequate for healthy iron-sufficient children in this rural area of Malawi, but iron-deficient children require additional bioavailable iron to correct their iron deficit.
