Antirachitic properties imparted to inert fluids by ultraviolet irradiation.

The fact that inert fluids can be activated and rendered antirachitic by means of irradiation was reported by us some months ago. 1

Steenbock has reported a similar result in relation to the production of a growth-promoting factor. He has also confirmed our observations in regard to rickets, having been able by means of irradiation to render “fats” active in preventing this disorder. 2 In our experiments various inert fluids were irradiated with the mercury vapor lamp for one hour at a distance of one foot, in order to ascertain whether by this means they could be endowed with antirachitic potency. It was found that cotton seed oil and linseed oil could be rendered specifically active by this means. After these oils had been thus irradiated they were able to protect rats from rickets when 0.1 cc. daily was fed in addition to the standard rickets-producing dietary (No. 84). The irradiated oils were able to store this factor for a considerable period. These experiments demonstrate the possibility of producing an antirachitic factor in vitro.