Anaemia due to iron deficiency is a major public health problem among adolescent girls in India despite long standing supplementation programs. The standard therapeutic dose of oral iron used for treatment of mild to moderate anaemia is relatively high and is often associated with gastrointestinal side effects which may reduce adherence. Evidence from recent studies suggests that lower doses of iron may be equally effective in improving haemoglobin levels but data on their effect on body iron status and long term sustainability are limited in Indian adolescents.

This study is a cluster randomised controlled trial conducted among adolescent girls aged 12 to 19 years residing in government residential hostels in Mahabubnagar district of Telangana. The trial will compare the relative efficacy of three daily doses of elemental iron 45 mg 60 mg and 120 mg each given with folic acid for a period of 90 days. Hostels will be used as the unit of randomisation to minimise contamination and to enable supervised administration of supplements.

The primary objective of the study is to evaluate whether lower doses of iron are not inferior to the standard higher dose in improving haemoglobin levels at 90 days. Secondary objectives include assessment of changes in iron status indicators gastrointestinal tolerability and sustainability of treatment effects at one year follow up. The study also aims to examine the association between menstrual blood loss and response to iron supplementation. The findings are expected to provide evidence to inform optimal iron dosing strategies for anaemia control programmes targeting adolescent girls.