EFFECT ON VARIOUS PHYSIOLOGIC PROCESSES 661 



feces occur.s in rickets.^ As a consequence, the ash content of the blood 

 is reduced, and less calcium and phosphate are deposited in the bones. 

 Table 6 summarizes some of the earlier data in regard to the calcium and 

 phosphorus balances in rachitic children before and after treatment with 

 cod liver oil or ultraviolet light. 



There can be little doubt that cod liver oil and ultraviolet light therapy- 

 bring about a profound alteration in the metabolism of calcium and of 

 phosphate in rickets. Thus, in all cases, the equilibrium of these com- 

 ponents is changed from a slightly negative or slightly positive balance in 

 rickets to a strongly positive one, by the therapy designed to bring in- 

 creased vitamin D to the tissues. The calcium loss in the stools is in- 

 variably greatly reduced after the rachitic children have been given cod 

 liver oil or after they have been irradiated with ultraviolet light. The 

 excretion of calcium in the urine, which, in any case, is quite insignificant, 

 may tend to increase slightly after the treatment of the rachitic infants. 

 When the rise does occur, it must be a reflection of the greatly increased 

 proportion of calcium which has been absorbed. 



Phosphorus, in the form of phosphate, is greatly decreased in the feces 

 when sources of vitamin D such as cod liver oil or ultraviolet irradiation are 

 given to rachitic infants. However, the considerable phosphate elimina- 

 tion in the urine, which occurs in the case of rachitic infants, is still further 

 increased when the rachitic condition is improved by this form of medica- 

 tion. The reduction of fecal phosphate is so much greater than the in- 

 crease in urinary phosphate that the phosphate balance inclines strongly 

 to the positive side when the rachitic infant improves in health. 



McCance-^^ furnished considerable data of a similar nature in the case 

 of a young girl with "resistant rickets," due to a raised resistance to vita- 

 min D w^hich had persisted since her childhood. She was treated for 

 almost a year with vitamin D. As soon as the medication was begun, the 

 pattern of the calcium and phosphate metabohsm as obtained from excre- 

 tion and absorption data changed from the rachitic to the normal. This 

 normal pattern of metabolism of calcium and phosphate was maintained 

 throughout the year during which the medication was continued and the 

 balances were followed. Liu and co-workers^^^ reported that vitamin D 

 exerted a similar effect on calcium and in phosphate excretion in the case 

 of an adult woman suffering from osteomalacia. Harris^^'' points out that 



2*5 R. A. McCance, Quart. J. Med., 40, (n.s. 16), 33-46 (1946). 



=56 S. H. Liu, H. I. Hsu, H. C. Chao, and S. H. Cheu, /. Clin. Invest., 20, 255-271 

 (1941). 



2" L. J. Harris, Vitamin D and Bone, chap. XIX in G. H. Bourne, Biochemistry and 

 Physiology of Bone, Acad. Press, New York, 1956, pp. 581-622. 



