The study will be carried out in two phases in Sangam Vihar, Delhi. The survey will be conducted to identify children in the age group of 24-36 months. After obtaining consent, an enrollment form with detailed socio-demographic information about the child will be filled. Blood and urine samples will be collected for estimation of iron status, oxidative stress, immune and interleukin markers. Based on iron status, two randomization lists will be generated i.e. one for iron sufficient and other for iron deficient children. Children will be randomly allocated to receive one of the four interventions (60 in each group) for 180 days. The intervention will be either Iron Tablets (IT) or Iron and Zinc tablets (IZ) or Biscuits fortified with Iron (IB), or Placebo tablets (CO). Children in the iron groups (IT and IB) will receive 12.5 mg/day of iron. Children allocated to receive Iron and Zinc (IZ group) will receive 10 mg/day of Zinc in addition to 12.5 mg/day of Iron. The fortified biscuits (IB) will be formulated by CFTRI, Mysore, India and will have iron in the form of iron sulphate. The iron (IT group) or iron and zinc (IZ group) fortified dispersible tablets will be procured from WHO manufactured by Nutriset (Maluanlay, France). Tablets will have iron salt in the form of ferrous sulphate and zinc in the form of zinc sulphate. The interventions at the baseline on Day 3, on Day 30 (on completion of Phase -I) and on Day 180 (on completion of Phase-II) will be given at the clinic prior to the post 3 hour blood collection. Regular supplementation will be given at home. Children will be followed up on a biweekly basis by the field worker for delivery of the intervention, collection of morbidity and compliance information from the mother/caretaker of the child. During follow-up, blood sample for interleukin levels will be taken in the event of an illness such as diarrhea, pneumonia, fever and severe illness/hospitalization. At the completion of Phase-I (on day 30) and Phase - II (on day 180), the blood and urine samples will be collected again for estimation of iron status, oxidative stress, immune and interleukin markers.