Vitamin E : Health Benefits, Part 2

by MedlinePlus

(Page 2 of 5)

Colon cancer prevention

There is not sufficient scientific evidence to determine if vitamin E prevents colon cancer. In patients with previous colon cancer, a combination of vitamins A, C, and E has been reported to reduce the risk of developing a new colon cancer. Preventive benefits have also been suggested in those with no prior colon cancer when vitamin E is used in a multivitamin, but not when used alone. Recent results of the Women's Health Study report no overall reduction in cancer risk with daily use of vitamin E, although this study was not large enough to look at colon cancer specifically. Additional research is necessary in this area before a firm conclusion can be reached.

Dementia / Alzheimer's disease

Vitamin E has been proposed and evaluated for the prevention or slowing of dementia (including Alzheimer's type), based on antioxidant properties and findings of low vitamin E levels in some individuals with dementia. There is some evidence that all-rac-alpha-tocopherol (synthetic vitamin E) 2000 IU/day is similar in efficacy to selegiline (Eldepryl) and superior to placebo for slowing cognitive function decline in patients with moderately severe Alzheimer's disease, but no additive effect was observed when used in combination with selegiline. Retrospective data suggests that long-term combination therapy with donepezil (Aricept) 5mg and vitamin E 1000 IU/day may help slow cognitive decline in patients with Alzheimer's disease. Overall, the evidence remains inconclusive in his area.Other research suggests that vitamin E from dietary sources or supplements does not affect the risk of developing Alzheimer's disease or vascular dementia.

Diabetes mellitus

Vitamin E has been proposed for the prevention of types I or II diabetes; for the improvement of abnormal sugar control in diabetes; for prevention of platelet dysfunction and atherosclerosis in diabetes; for the correction of vitamin E deficiency in diabetic patients; and for the prevention of diabetic complications of the eye, kidneys, and nervous system (neuropathy, retinopathy, nephropathy). It is not clear that vitamin E is beneficial in any of these areas, and further evidence is necessary before a clear conclusion can be drawn.

Dysmenorrhea

There is preliminary evidence of possible benefits of vitamin E supplementation to reduce chronic menstrual pain, although additional research is necessary in this area before a firm conclusion can be reached.

G6PD deficiency

Vitamin E supplementation has been studied for the inherited disorder G6PD deficiency with conflicting evidence. Additional research is necessary before a clear conclusion can be drawn.

Glomerulosclerosis (kidney disease)

It has been suggested that proteinuria (protein in the urine) may be reduced with the use of vitamin E in patients with focal segmental glomerulosclerosis which is refractory to standard medical management. However, further research is necessary before a clear conclusion can be drawn.

Healing after photorefractive keratectomy

High-dose vitamin E plus vitamin A (taken by mouth) may improve healing of the cornea and improve visual acuity (sharpness) following laser surgery for vision correction. Animal research suggests that topical vitamin E on the eye may be helpful. Additional research is necessary before this use of vitamin E can be concluded as being safe or effective.

High cholesterol

The effects if vitamin E on cholesterol levels and atherosclerosis have been studied in numerous laboratory, population, and clinical trials. It remains unclear if there are clinically meaningful benefits, and it is not known what the effects of vitamin E are compared to (or in combination with) other agents which have been clearly demonstrated as beneficial for lowering lipids. Further research is warranted before a clear conclusion can be drawn.

Immune system function

Studies of the effects of vitamin E supplementation on immune system function have yielded mixed results. There are results suggesting enhancement of lymphocyte proliferation, decreased production of immunosuppressive prostaglandin E2, and decreased levels of immunosuppressive serum lipid peroxides. Further research is needed before a clear conclusion can be drawn.

Intermittent claudication

Multiple studies have evaluated the use of vitamin E in patients with peripheral vascular disease, to improve exercise tolerance and intermittent claudication (pain in the legs with walking due to cholesterol buildup in blood vessels). Although some results have been promising, most studies have been small and poorly designed. It remains unclear if vitamin E is beneficial in this condition.

Macular degeneration

Like other antioxidants, vitamin E has been suggested to prevent, slow progression, or improve macular degeneration. The scientific evidence in this area is not conclusive, although there is some suggestion that alone vitamin E may not be beneficial. In combination with beta-carotene and vitamin C it may similarly not be significantly beneficial. Additional research is necessary before a clear conclusion can be drawn.

Parkinson's disease

The scientific evidence is inconclusive in this area.

Premenstrual syndrome

The scientific evidence is inconclusive in this area.

Prostate cancer prevention

The role of vitamin E supplementation for prevention of prostate cancer is controversial. There are numerous laboratory studies which support possible anti-cancer properties. However, the results of population research and human research have been mixed, with some studies reporting benefits and others finding no effects. There is ongoing research in this area, including a very large well-designed study of vitamin E and selenium, the "SELECT" trial.

Respiratory infection prevention

Daily supplementation with oral vitamin E 200 IU does not appear to affect the incidence, duration, or severity of pneumonia (lower respiratory tract infections) in elderly nursing home residents or alter patterns of antibiotic use, although there may be a protective effect against colds (upper respiratory tract infections). Additional research is warranted before a recommendation can be made.

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