British Food Journal Volume 39 Issue 8 1937

However, as the result of recent research, information has been accumulating which points to the fact that all anti‐rachitic agents are not utilised by the body in the same relative proportions. For instance, from the clinical standpoint it has been shown by Hess and his co‐workers (1933) that more anti‐rachitic units were required to prevent or cure rickets in children when ciosterol (irradiated ergosterol) was used than when cod liver oil was the method of administration. These clinical findings have found support from animal experiments. Thus, in work with chickens it was demonstrated that 100–200 times the number of units was required if irradiated ergosterol was used instead of cod liver oil.