The distribution of iron among various fractions of human milk was determined by gel filtration, ultrafiltration, and atomic absorption spectrophotometry. Total iron varied between 0.26 and 0.73 μg/ml; 15 to 46% of the iron was bound to the lipid fraction and 18 to 56% was found in a low molecular weight fraction. Only a small amount of iron was bound to lactoferrin, the major iron-binding protein of human milk; the iron saturation of this protein was found to be 1 to 4%, at the most. Thus, much less iron is bound to lactoferrin than earlier reported; this may be important in regard to the suggested role of this protein as a bacteriostatic agent. A correlation was found between iron and fat content during the course of a single nursing, but not between iron and lactoferrin.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health