Abstract
The effect of vitamin D on the metabolism of Ca and P has been studied in-tensively for many years, and is still under active investigation (1). There is the possibility, however, that it may affect, directly or indirectly, aspects of metabolism other than mineral. For example, since ergocalciferol is known to influence citrate metabolism (2) it may affect the metabolism of other substances such as fatty acids. It has been shown recently (3-5) in fact, that the administration of ergocalciferol to rachitic rats increases the uptake of 32P-orthophosphate by the phospholipids of the intestinal mucosa, liver, and kidney, and that it increases the triglyceride content of bone (6). Although toxic doses of vitamin D do not influence the proportions of the various fatty acids in the livers of rachitic rats (7), it would be of interest to know whether nontoxic levels of vitamin D would influence fatty acid distribution in the triglycerides significantly, and thus perhaps indirectly influence the structure of the cell membranes in areas critical for Ca absorption (8).
