Zinc and iron supplementation trials in Nepal and Tanzania
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The Lancet 2006; 367:816
DOI:10.1016/S0140-6736(06)68334-7
http://www.thelancet.com/journals/lancet/article/PIIS0140673606683347/fulltext
Bruno de Benoist (a), Ian Darnton-Hill (b), Sean Lynch (c),
Lindsay Allen (d) and Lorenzo Savioli (a)
Affiliations
(a) WHO, 20 Avenue Appia, Geneva, Switzerland
(b) UNICEF, New York, NY, USA
(c) Eastern Virginia Medical School, Norfolk, VA, USA
(d) USDA-ARS Western Human Nutrition Research Center, University
of California, Davis, CA, USA
The results of the trials designed to assess the effect of iron
supplementation on morbidity and mortality in young children in
Tanzania and Nepal (Jan 14, pp 133 and 144)[1,2] confirm that
iron supplementation is effective in reducing iron deficiency
and anaemia. However, one of the trials[1] also shows that there
are situations in which iron supplementation might be associated
with increased risk of death or severe morbidity leading to hos-
pital admission. This increased risk is attributed mainly to ma-
laria and other severe infectious diseases, but the results of a
substudy within that trial suggest that the risk might not be
distributed uniformly across the whole sample of children.
As soon as these results were known, WHO convened an expert
meeting to review critically the data available from both trials
and to assess their possible public-health implications. The
main conclusions of that meeting are presented here.
The experts recognised the scientific importance of the results
of these trials for policymakers. Nevertheless, they suggested
that caution be exercised in changing policy on the basis of a
single set of observations. In light of the findings and until
WHO recommendations are possibly revised, in regions with a high
prevalence of malaria and other infections, they advised that
iron and folic acid supplementation for young children be tar-
geted to those who are iron deficient. Every effort should also
be made to combine iron supplementation with effective treatment
and control of malaria and other severe infectious and parasitic
disease.
They also emphasised that these findings should be regarded as
specific to iron and folic acid supplementation of young chil-
dren in regions of the world where malaria transmission is in-
tense and severe infectious disease prevalence is high. The con-
clusions should not be extrapolated to fortification or food-
based approaches for delivering iron.
These results show that additional research and assessment of
existing programmes is needed urgently to develop the most ef-
fective strategies for controlling iron deficiency and anaemia
in regions where malaria transmission is intense and the preva-
lence of infection high. Other important research issues in-
clude: determining the dose of an iron supplement that is both
safe and effective, the optimum duration of supplementation, the
mode of iron delivery, the pathophysiological basis for the in-
crease in adverse events among iron-sufficient children who are
exposed to malaria and infectious diseases, and an assessment of
possible interactions between iron and other micronutrients, es-
pecially zinc. Finally, it will be necessary to examine more
critically the possibility that iron supplementation could af-
fect the course of other potentially fatal infectious disorders
such as HIV/AIDS and tuberculosis.
The important message of these trials is that, although iron
supplementation is effective in combating iron deficiency, a
better understanding of the potential risks and benefits of dif-
ferent levels and modes of delivery in some environments is re-
quired. Although iron deficiency is frequently the main factor
contributing to anaemia, the control of anaemia requires a mul-
tisectorial approach that, through integrated interventions, ad-
dresses the various factors that have a significant role in a
given community.
We thank Olivier Fontaine for his contribution to this letter.
We declare that we have no conflict of interest.
References
1. Sazawal S, Black RE, Ramsan M, et al. Effects of routine pro-
phylactic supplementation with iron and folic acid on admission
to hospital and mortality in preschool children in a high ma-
laria transmission setting: community-based, randomised, pla-
cebo-controlled trial. Lancet 2006; 367: 133-143.
2. Tielsch JM, Khatry S, Stoltzfus R, et al. Effect of routine
prophylactic supplementation with iron and folic acid on pre-
school child mortality in southern Nepal: community-based, clus-
ter-randomised, placebo-controlled trial. Lancet 2006; 367: 144-
152.
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Rana Jawad Asghar MD. MPH.
Coordinator South Asian Public Health Forum
mailto:jawad@alumni.washington.edu
http://www.DrJawad.com
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