While there are many useful applications for vitamin E in clinical nutrition, it acquired a reputation many years ago as a sexual aid which it did not deserve.
More important relationships between vitamin E and human disease exist in the realms of circulatory, inflammatory, and degenerative diseases. In these conditions, successful treatment and even prevention may depend upon vitamin E intake well above dietary levels. Research in this area typically utilizes doses of 100-600 IU or more of vitamin E compared to the RDA of 10 IU/day.
Cardiovascular disease was an early focus of clinical practitioners such as the Shute brothers, medical doctors in Canada who popularized vitamin E for heart disease in the 1950s. Lack of controlled studies plagued the reputation of vitamin E for these conditions until recently. Now it appears that vitamin E may help prevent atherosclerosis by inhibiting pathological oxidative changes in the low-density lipoprotein (LDL) particle. This is vital information for the majority of patients, since atherosclerotic heart disease is still the number one cause of age-related death in the Western world. In some studies, vitamin E has also raised HDL cholesterol levels and reduced excessive clot formation in the blood.
It is still unclear, nonetheless, what role vitamin E can play in the treatment of existing cardiovascular disease. The best evidence appears to be for the peripheral vascular condition known as intermittent claudication. Several studies have shown a beneficial effect on walking ability using 300-1600 IU/day of vitamin E.
The effect of vitamin E on inflammatory conditions such as arthritis and cystic breast disease appears to stem from its ability to modify prostaglandin formation in the tissues. Osteoarthritis researchers, using either 400 or 600 IU/day, showed vitamin E to be effective in two placebo-controlled studies. In a recent study using 1620 IU/day, vitamin E gave significant relief to 81 percent of rheumatoid arthritis patients, which was superior to the effects of anti-arthritic drug used for comparison. Promising case reports have also been published suggesting that vitamin E may be useful in various other autoimmune disorders.
Many pathological aspects of aging seem to be connected with the production of free radicals, which are formed when the body's antioxidant defense mechanisms are inhibited. Because of its high antioxidant activity, vitamin E may have an important protective role against such degenerative conditions as cataracts, cancer, and, as mentioned above, atherosclerotic vascular disease. The damaging effects of air pollution and smoking have been studied recently suggesting that vitamin E may reduce free radical activity related to these factors.
With the large number of patients suffering from or at risk for many of the above conditions, I believe a general recommendation of at least 100 IU/day of vitamin E to most patients is well justified. Following, I will discuss how to select a vitamin E supplement and comment on potential contraindications to high-dose vitamin E therapy:
Many patients are already interested in taking vitamin E and want to know how much to take, what form to choose, and what side effects, if any, can be expected. What advice would you give?
Vitamin E is actually a mixture of eight different isomers, each having a different potency. D-alpha tocopherol is the most potent and is the standard by which vitamin E activity is measured. This is not to say that the other natural isomers (beta, delta, gamma, etc.) are not useful; they also contribute to antioxidant activity in the body. The entire spectrum of isomers may be obtained by using a mixed tocopherol supplement, which actually has more antioxidant activity per labeled dose than standard d-alpha tocopherol.
Synthetic vitamin E is identified by the letters dl in the name dl-alpha tocopherol. While many practitioners feel that synthetic vitamins are less desirable, most vitamins used today are, in fact, synthesized from various raw materials. Moreover, most research studies have used synthetic vitamin E in demonstrating positive effects on the many conditions we discussed earlier. Finally, by law, a vitamin E supplement must possess the activity printed on the label, so a 400 IU supplement has the same measurable potency whether synthetic or natural (more synthetic E is put into the capsule to bring it up to labeled potency).
Notwithstanding the above considerations, I still find it difficult to recommend synthetic vitamin E as a general rule. There is an unsettled issue regarding the as yet unknown fate of 1-alpha tocopherol in human metabolism. Until long-term studies prove the safety of this unnatural isomer, I only recommend dl-alpha tocopherol to patients who cannot afford natural vitamin E.
Still another choice to be made among vitamin E supplements is esterified versus unesterified vitamin E. Esterification serves to extend the shelf-life of the vitamin and is indicated when either of the terms acetate or succinate is added to the name tocopherol on the label. The only drawback to this modification is that the supplement must be digested for the vitamin E to become active. Thus, this form would not be effective when used topically or in food preservation. It is alarming how many vitamin E skin products use this inactive form. For external use, a mixed tocopherol product would be a good unesterified choice.
Even natural vitamins may exhibit side effects when taken in large doses, and some reports or opinions about vitamin E have been made in this regard. Temporary gastric upsets and delayed wound healing have been reported. Patients with coagulation deficiencies or who take anticoagulant medications should be monitored for increased bleeding tendencies. Some cardiologists recommend against high-dose vitamin E in patients with diseases of the heart valves due to possible increases in leakage. Finally, hypertensive patients should take vitamin E in small doses initially with gradual increases while monitoring blood pressure for sudden elevations.
Vitamin E may well be the most important supplement for your patient to take. Proper attention to specific health risk factors, supplement forms, and possible contraindications will ensure the best professional use of this valuable nutrient.
References
Bendich A, Machlin LJ: Safety of oral intake of vitamin E. Am. J. Clin. Nutr., 48:612-619, 1988.
Esterbauer H, et al: Role of vitamin E in preventing the oxidation of low-density lipoprotein. Am. J. Clin. Nutr., 53:314S-321S, 1991.
Gerber JM: Handbook of Preventive and Therapeutic Nutrition. Gaithersburg: Aspen Pubs, 1993.
Kolarz G, et al: High dose vitamin E and rheumatoid arthritis. Akt. Rheumatol., 15:233-237, 1990.
Packer L: Protective role of vitamin E in biological systems. Am. J. Clin. Nutr., 53:105S-115S, 1991.
James M. Gerber, MS, DC
Portland, Oregon