Vitamin E is unique among vitamins for the variety of undesirable manifestations observed when it is absent from the animal diet.
Muscle degeneration is a universal symptom, but in some species other systems are affected first. In cockerels and young pigs, testicular atrophy occurs early. Laying fowls show the effect of vitamin E deficiency by producing eggs with low hatchability, due to weak and deformed embryo. Capillary fragility, plasma protein changes, and other abnormalities in the blood vessels occur in chickens, characterised by subcutaneous haemorrhages and oedema (exudative diathesis). The central nervous system is affected in chicks (encephalomalacia or "crazy chick disease") and the adipose tissues in pigs, cats and mink ("yellow fat disease" or steatitis). In all other species, the muscle system is affected first. For example, leg weakness in puppies, "Stiff lamb disease" and "White muscle disease"; as well as involvement of the heart muscles in calves.
Physiological stresses, which cause a drain on metabolic reserves, increase the need for vitamin E (Harris & Quaife-1952). The rapid growth of chicks induced by the feeding of high energy feeds, fish oils, antibiotics, incompletely balanced proteins, environmental stresses, drugs, athletics, are examples.
Some fodders are low in effective tocopherol (vitamin E) content, and the vitamin E content of pastures varies in different seasons and at different times of the year. In cattle and poultry the use of cod liver oil precipitates vitamin E deficiency signs, and it has been estimated that the use of small quantities of oil raises the tocopherol requirement many times; "at least fifty-fold in cattle". It is possible that "yellow fat disease" in mink may be due to vitamin E deficiency induced by the presence in the diet of fish scraps and other substances rich in rancid or unsaturated fats.
"In general vitamin E is effective whenever there is a deficiency of oxygen or of blood supply or where better utilisation of oxygen in tissues is desirable. It is the 'antithrombin' in the blood stream, and as such has the important job of preventing clotting while not interfering with the clotting mechanism in wounds. It increases the auxiliary circulation around damaged areas, wound healing and produces small non-contracted scars." (W. E. Shute).
It is thought that vitamin E may be a co-enzyme in protein metabolism and in this role may be needed for creative formation (Backman, 1955). It is thought also to facilitate intracellular phosphorylation by reducing the oxygen requirement (Vannotti, 1955).
Data from various independent sources combine to indicate a fundamental role of vitamin E in processes concerned in protein metabolism and thus in the maintenance of cell and enzyme integrity. Through its influence on the hormonal system vitamin E creates a feeling of well-being in the animal; it eats more heartily and the metabolic systems will convert the intake of feed to the maximum caloric values. Vitamin A and all vitamins and minerals are better absorbed into the tissues, and better preserved by the oxygen effects of vitamin E. Strong healthy growth is promoted in young animals; maximum fertility attained in older animals.
"Bloodmares not given Alpha-tocopherol bred to stallions not taking Alpha-tocopherol had a pregnancy percentage of 63%. The corresponding figure when both animals were taking Alpha-tocopherol was 87%." Darlington-Chassels, D.V.M. (The Summary, 1957).
"Stallions work at optimum when taking natural Alpha-tocopherol. The quality of the sperm is improved. Their feeding habits are excellent. Nervous horses can become 'normal' individuals. It is possible for stallions to give additional services if required." (The Summary, 1956).
Whether vitamin E is used in supplementary feeding or in therapy, first-class results may be obtained only by adequate dosage, with a first-class product.
Leading clinical authorities claim that "d-Alpha" tocopherol has a much greater "biological potency" than "dl-Alpha" tocopherol: (1) It is absorbed better and tolerated more easily: (2) Large doses do not cause stomach upsets.
(1) Curti, G. M., University of Milan, Italy—A comparison of Biological Activity of the Dextra-Rotary and Racemis Type of Alpha Tocopherol Acetate (to be published in the Biochemistry Journal in Italy).
(2) "In this connection, I should like to point out that my own observations and experience with vitamin E therapy have abundantly shown over the course of years that it becomes much more active when it is thoroughly masticated and mixed with saliva. It appears that ptyalin and diastise enzymes of the saliva in their turn activate the vitamin E, too, to a kind of enzymic state by creating a vitamin E in statu nascendi. This significant physiological process explains, too, why natural vitamin E is probably much more active biologically than the synthetic one, which does not lend itself readily to these changes." L SCHMIDT, M.D., Consultant to the Central Coal Board, London, England. "The Summary", December, 1955.