We found that: (i) Babies of non-anemic and anemic mothers who were exclusively breastfed until six months age did not develop iron deficiency anemia or iron deficiency; (ii) The iron status of the babies had no relation with the breast milk iron and lactoferrin concentration at any particular time; (iii) The declining haemoglobin and serum ferritin of babies of non-anemic and anemic mothers significantly correlated with the declining breast milk iron and lactoferrin concentration. The gene discussed is LTF; the disease is Iron deficiency anemia.