Selenium disease/disorder effects

The interrelations between vitamin E and selenium in cattle and sheep are undoubtedly as complex as they are in other species. It seems reasonable to state that vitamin E, in combatting the toxicity of unsaturated fat, acts as an antioxidant, for its effect can be duplicated by many other antioxidants and redox dyestuffs. Similarly it is indisputable that selenium is a dietar essential for ruminants and that its absence from their diet results in muscular disease. Both unsaturated fat excess and selenium deficiency must produce primary disturbances in the muscle cells. These disturbances need not be common to both, for muscle reacts similarly to a variety of biochemical insult. In the presence of selenium and the absence of unsaturated fat, vitamin E requirements of ruminants appear to be extremely small. The failure to produce reproductive disorders in ruminants by experimental vitamin E deficiency, and the failure to produce muscular disease on fat-free diets deficient in vitamin E but likely to have been adequate in selenium content is evidence of this contention. How vitamin E acts in preventing muscular disease due to selenium deficiency, however, is not known, and this aspect needs elucidation. 

Heart disease and selenium—A review of the effects of selenium deficiency reveals a repetitious undercurrent of vascular-type lesions suggesting a heart involvement in selenium disorders. Sudden death associated with selenium deficiency in newborn or rapidly growing lambs and calves apparently results from weakening of the heart muscle, commonly called white muscle disease. Selenium-deficient monkeys also have heart lesions. This disorder is characterized by white streaks in muscles, and in some cases, by abnormal electrocardiograms. Often, the animals affected with this diseeise die suddenly when they are subjected to moderate stresses. 

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