Clinical Experience With Irradiated Ergosterol

In 1924 it was shown independently by Hess¹and by Steenbock²that various foods, such as oils, milk and cereals can be endowed with specific antirachitic properties merely by subjecting them to ultraviolet radiations. The year following, these investigators³found that the substance which undergoes this specific change is a sterol, seemingly cholesterol, which has long been known to be a constituent of every cell in the animal body. These studies and their obvious connotations definitely identified actinotherapy with photochemistry. The subject was elucidated still further about a year ago by the investigations of Windaus and Hess⁴and of Rosenheim and Webster⁵who, by means of chemical analyses and spectral absorption tests, determined that it is ergosterol, a sterol closely allied to cholesterol, which is activated by the ultraviolet rays in this remarkable way. Ergosterol was one of the large number of sterols known to