Background: Protein Energy Malnutrition is an important cause of child morbidity and mortality in middle- and low-income countries. It has been suggested that excessive free radical activity may be responsible for the clinical manifestation of kwashiorkor. Antioxidants may be able to curb excessive free radical activity and prevent the development of kwashiorkor in susceptible children.

Objectives: To evaluate the benefits of supplementation of vitamin E, selenium, cysteine and riboflavin (alone or in combination) in preventing kwashiorkor.

Search strategy: We conducted searches of CENTRAL 2009 (The Cochrane Library 2009 Issue 2), MEDLINE 1966 to 2009, EMBASE 1980 to 2009, CINAHL 1982 to 2009, LILACS 1982 to 2009, Meta register of Controlled trials, Open Sigle, African Index Medicus.

Selection criteria: Randomised controlled trials (RCTs) and quasi-RCTs evaluating vitamin E, selenium, cysteine and riboflavin alone or in combination in healthy pre-school children in middle- and low-income countries.

Data collection and analysis: Two authors extracted and independently analysed data.

Main results: One cluster-RCT including 2372 children met our inclusion criteria. Children were randomised, based on household, either to a supplement containing all four micronutrients or to placebo. No statistically significant difference in the incidence of kwashiorkor between the intervention and control groups could be demonstrated at 20 weeks (RR 1.70; 95% CI 0.98 to 2.42). Nor could any statistically significant difference in all-cause mortality be demonstrated (RR 0.75; 95% CI 0.17 to 3.36).

Authors' conclusions: Based on the one available trial, we could draw no firm conclusion for the effectiveness of supplementary antioxidant micronutrients for the prevention of kwashiorkor in pre-school children.