Interaction of vitamin D and dietary factors in the healing of rickets in rats

RICKETS produced in rats by a high calcium-low phosphorus diet may be healed either by the administration of vitamin D or by the addition of a source of phosphorus to the diet. The estimation of the influence of small additions of sources of phosphorus or of other related changes in composition of the diet has, however, received much less attention than the relation between the degree of healing and the dose of vitamin D. It is of considerable practical importance to find some means of expressing the antirachitic effect of such dietary factors, both alone and in conjunction with vitamin D, more especially in those cases where a measure is to be made of the vitamin D content of foodstuffs containing phosphorus compounds. From the theoretical point of view, the discovery of such a relation would throw some light on the synergism of vitamin D and phosphorus compounds.