The effect of fortification of food with iron to provide 10 mg elemental Fe/child per d was studied in preschool children maintained on a cereal diet, over a 5-month period. 2. The absorption of 5 mg Fe as ferrous sulphate mixed in one meal was 3.3% of the test dose and when 3.3 mg was given with each of three meals over a 2 d period the corresponding value was 4.8%. 3. The mean absorption of a test dose of ferrous ascorbate studied in twenty-four children midway through the trial was 42%. 4. The only beneficial effect of Fe fortification in this time-period in the experimental group was the prevention of the decrease in packed cell volume which occurred in the control groups.
