The purpose of the study to be reported was to determine the value of percomorph liver oil1 as the sole antirachitic agent in healthy young infants, ultimate reliance being placed on roentgenologic rather than clinical criteria for detecting rickets.
There has been considerable confusion concerning adequate prophylactic dosage of vitamin D, especially of the concentrates, such as viosterol. Studies in which unassayed vitamin D products and clinical rather than roentgenologic data have been used have clouded the issue.
Shelling and Hopper2 have pointed out the inadequacies of the early studies in which cod liver oil and viosterol were used in the prevention of rickets. There has been much controversy over the relative efficacy, unit for unit, of natural and irradiated products containing vitamin D. Recently Shelling and Hopper2 maintained that cod liver oil and viosterol are of equal antirachitic potency in relation to the number of units