A marked increase of calcium uptake in the ATP‐depleted red cells of patients with iron deficiency

Calcium (Ca) uptake was markedly increased in ATP‐depleted red cells of patients with iron deficiency anemia (IDA) compared to ATP‐depleted normal red cells. The extent of increased Ca uptake was related to the severity of iron deficiency as judged by decreased mean cell volume. Moreover, the increased Ca uptake returned to normal levels after oral iron supplementation therapy. The net calcium content of fresh red cells from iron‐deficient individuals was the same as in red cells from normal subjects. Sodium influx and ferric ion uptake appeared to be virtually unaffected in the iron deficient red cells.