The cure of infantile rickets by sunlight as demonstrated by a chemical alteration of the blood

Abstract

It has been shown by one of us (A. F. H.) that the rickets of infants can be cured merely by frequent exposures to the sun's rays. 2 Animal experiments carried out in this laboratory confirmed these clinical observations. They clearly demonstrated that rickets could be either prevented or brought about in rats fed a standard diet, according to whether they were subjected for short periods to the sun's rays or were kept at all times in the dark. The present report adds substantiation from the chemical side to the clinical and anatomical evidence brought forward in the previous papers.

In a recent article Howland and Kramer 1 have shown that the inorganic phosphorus of the serum of infants suffering from active rickets is reduced, and that during the process of healing, especially upon the administration of cod fiver oil, the phosphorus content gradually rises to normal. In view of the marked clinical improvement following sun treatment, it seemed of interest to ascertain whether this procedure was accompanied by a chemical alteration of the blood. For this purpose the rapid colorimetric method of Bell and Doisy 2 was used, in which the color is developed in protein-free filtrates through the reduction of phosphomolybdic acid by hydroquinone in alkaline sulphite solution. Special attention was paid to the inorganic phosphorus of the blood, although in many instances the so-called acid-soluble and total phosphorus was also estimated. It will be seen from the accompanying chart that the normal figures for inorganic phosphorus are sufficiently constant to render this test of clinical value (Table 1)

The infants were placed in the direct sunlight for a half hour to several hours, the period varying according to the intensity of the sun and the sensitiveness of the skin.