Observations on cod-liver oil and rickets

In view of the nearly specific action that cod-liver oil has on rickets, it is of interest to inquire into the nature of the substance conferring on it the therapeutic properties. Several attempts have been made to isolate from it materials that could be made responsible for its action. Gautier and Morgues 1 isolated the organic bases contained in the oil and separated from them two alkaloid-like substances besides the simpler aliphatic amines. Funk 2 also worked with this mixture of bases which he fractionated in various ways. None of these observers, however, have published any data on the action of the isolated material. Stöltzner 3 claims, without giving any details of his evidence, except the statement that he cured even the worst cases of rickets, that hydroxy acids confer upon cod-liver oil its pharmacological properties. Freudenberg and Klocmann 4 had expressed similar ideas and prepared calcium salts of the unsaturated acids of cod-liver oil which they used in the treatment of spasmophilia.

Wacker and Beck 5 believe that“besides other chemically not yet well characterized substances, cholesterol plays a significant röle in the antirachitic fat soluble factor A.”

With a good test object now available in the rat made rachitic on the phosphorus low diet described by Sherman and Pappenheimer, the problem of determining the point in question is much easier. The rickets of children and the experimental rickets in rats both respond in the same manner to treatment with cod-liver oil^l and there is no reason to believe that the substance active in the two cases should not be the same.

We first isolated the crude bases according to Gautier and Morgues and found them inactive. Next the oil was hydrolyzed with sodium hydroxide and the fatty acids separated.