Relation of Calcium to Blood Formation. ∗

Abstract

Previous investigations in this laboratory have shown that young albino rats maintained on a diet deficient in inorganic salts fail to grow normally and develop unique hematological abnormalities, including a marked polycythemia and a concurrent, chronic anemia. 1 , 2 Analyses of the diet 3 have demonstrated that it is extremely low in calcium, sodium and chloride, and deficient in potassium, magnesium, phosphorus, and possibly iron. 4 Inasmuch as a lack of calcium appeared to be the most serious inorganic deficiency in the ration, a study was made of the hematological effects produced by the addition of this element to the low-ash ration.

The effect of calcium was investigated by both the curative and preventive procedures in uniform, vigorous, young male albino rats, selected and cared for as described previously. 2 In the curative procedure, the animals were placed on the basal low-ash ration 2 for an 8-week preliminary period and then were given calcium carbonate at a level of 50 mag. of calcium daily, the amount consumed by comparable normal controls. During the experimental period, the basal low-ash ration was fed in that daily amount ingested by the animal during the final 2 weeks of the preliminary period. In the preventive procedure, the young rats were placed directly on the calcium-supplemented, low-ash ration. The amount of the basal low-ash diet fed was restricted to that daily quantity ingested by unsupplemented controls. Simultaneously, 2 types of control animals were studied for each calcium-supplemented group: (a) unsupplemented controls given the low-salt diet; (b) inanition controls fed the same daily amount of the basal low-ash ration as the unsupplemented controls but containing, in addition, the quantity of salt mixture ingested daily by normal animals of the same weight. Adequate amounts of the vitamins 2 were supplied daily to all animals in equal quantities.