Occult blood loss and iron balance in chronic renal failure.

: In 38 patients with chronic renal failure total daily blood loss and intestinal iron absorption were determined by means of a whole-body counter and radioiron. Bone marrow iron content was measured histochemically. Mean daily blood loss (corrected for laboratory blood sampling) and iron absorption were significantly higher than in normal controls. Bone marrow iron content was reduced in 46% of the patients. The results prove that gastrointestinal blood loss in patients with chronic renal failure is of such magnitude that negative iron balance results.