Iron Retention in Infancy

Abstract

The retention of iron by fourteen infants varying from 7 to 54 weeks of age has been studied throughout a total of 107 3-day balance periods. One infant was fed human milk, the others were given a basal diet of cow's milk, carbohydrate and orange juice. The daily iron intake was increased by giving egg yolk, spinach, a special cereal, or an iron salt, and the effect upon the retentions observed. The influence of the potassium, calcium and phosphorus intake levels upon the retention of iron has also been studied. The baby given human milk was never in negative balance, although the retention was always small. Those given cow's milk feedings alone, lost an average of 0.05 mg. of iron daily. The age of the infant had no apparent influence upon the ability to retain iron. Neither egg yolk nor spinach, in the amounts given, increased the iron retention. The retention was definitely increased when the infants were given the special iron-rich cereal or ferric ammonium citrate. No consistent relationship was observed between the iron retention and the intake of potassium, calcium or phosphorus. From studies of the iron retention after the ingestion of varying amounts of iron as food or as soluble salt, it appears that an intake of approximately 0.5 mg. per kilogram body weight is necessary to insure a retention of iron, and an intake of 1 to 1.5 mg. per kilogram permits ample retention. Ample retentions were observed with these intakes of iron, whether the source of iron was from food (special cereal and egg) or from a ferric salt (ferric ammonium citrate).