Abstract
In order to obtain further evidence regarding the possibility of increasing the antirachitic potency of cod liver oil, we have fed groups of young rats (six each) a standard rachitic ration 1 to which has been added 1 per cent of Norwegian cod liver oil. With one group the cod liver oil was exposed to the direct solar rays, according to the method outlined by Price. 2 A second group received the same amount of cod liver oil, which had been irradiated with a Mercury vapor lamp, at a distance of two feet, for twenty minutes. Control animals were given the non-irradiated cod liver oil. To make sure that the oil, which was obtained from the same source in each case, would be evenly distributed in the ration, it was mixed with 2 per cent of corn oil, a substance which has been shown to contain no antirachitic properties. Two groups of animals receiving the basal rations have been included for comparison. In one case the ration was irradiated with the Mercury vapor lamp in the same manner as the cod liver oil.
Our criteria of the effect of these rations has been the growth of the animals throughout an eight weeks period. The results are summarized in the following table:
It will be observed that the animals receiving the irradiated rations to which no cod liver oil was added made greater gains than those which were given the cod liver oil additions. It would seem, therefore, that the growth stimulation in the animals receiving the cod liver oil was the result of the antirachitic property of the cod liver oil, and not of the Vitamin A contained in the oil.
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