Association between iron supplementation and the presence of diarrhoea in Peruvian children aged 6–59 months: analysis of the database of the Demographic and Family Health Survey in Peru (DHS, Peru), years 2009–2019

INTRODUCTION: According to the WHO, anaemia is a severe public health problem when the prevalence is ≥ 40 %. In 2019, in Peru, 40·1 % of children (aged 6 to 35 months) are diagnosed as anaemic. This is a concern since, despite the efforts of the governments to reduce the prevalence, the problem has stagnated since 2011. The treatment applied to deal with anaemia is Fe supplementation. Although Fe is essential for cell function, an excess can produce adverse responses, such as gut inflammation affecting microbiota and resulting in diarrhoeic episodes. OBJECTIVE: To determine the association between diarrhoea and Fe supplementation in children with and without anaemia, controlling for different socio-demographic variables. DESIGN: We conducted via logistic regression to obtain diarrhoea prevalence ratios (PR), adjusted by age, sex, geographic region, water and sanitation service, and rurality. The survey asked for recent episodes of diarrhoea during the last 7 d; similarly, after the consumption of Fe supplements during the last 12 months before the survey. SETTING: Peru. PARTICIPANTS: The Demographic and Family Health Survey (DHS) is conducted annually at home among 14 202 children on average (2009–2019). RESULTS: Fe supplementation in the last 7 d (PR = 1·09) or the last 12 months (PR = 1·19) (P < 0·0001) was associated with an increased risk of diarrhoea. The same association was observed between Fe supplementation and the presence of anaemia. CONCLUSIONS: Fe supplementation is associated with diarrhoea and overuse in children should be avoided.