|Vitamin E |
Vitamin E was identified in 1922 as an essential nutrient in the diet. Vitamin E is one of the more potent biological antioxidants that protect cell membranes and other fat-containing parts of the body against damage from free radicals, peroxides and various pollutants.* Vitamin E became known as the “anti-sterility vitamin” because it was found to be necessary in normal reproduction.* Tocopherol, which means “to bear offspring” in Greek, was the name given to the isolate of wheat germ oil that contains vitamin E.
Vitamin E interacts extensively with other antioxidants, especially vitamin C and selenium.*1 These nutrients enhance each others’ effects. Vitamin E also improves the use of vitamin A, and may be necessary in the conversion of vitamin B12 to its most active form.*2 The recommended Dietary Allowance (RDA) for vitamin E is 30 IU per day. Nature’s Life offers a wide variety of forms and potencies, depending on your individual needs.
Vitamin E functions primarily as an antioxidant in protecting against damage to all cell membranes in the body.* It is actually incorporated into the lipid (fatty) protein of the cell membrane, where it acts to protect against the body’s natural free-radical metabolites, heavy metals such as lead and mercury, toxic chemicals and radiation.* Human studies also suggest that vitamin E may help inhibit the formation of abnormal cells.*3,4
Vitamin E’s protection against the oxidation of low-density lipoprotein (LDL or “bad” cholesterol) has been shown in recent studies to help maintain a healthy heart.* Two large studies show that both men and women who supplement with at least 100 IU of vitamin E per day, for at least two years, have a 37-41% better chance of maintaining a healthy heart.*5,6 Even more impressive are the results from a double blind study of 2,002 people taking 400 to 800 IU of vitamain E daily. The results indicated a 77% improvement in heart health.*7 Researchers in the above studies concluded that supplementation of vitamin E at higher levels than those achievable by diet alone may be needed to reduce oxidation of LDL cholesterol.*
Several large-population studies have demonstrated that vitamin E levels in the blood may be a better indicator of heart health than levels of total cholesterol. In one study, high blood cholesterol was predictive of poor heart health 29% of the time, high blood pressure was predictive 25% of the time and low levels of vitamin E was predictive almost 70% of the time.*8 Although amounts as low as 30 IU (the RDA) are effective at offering some protection, supplements greater than 400 IU a day are required to produce clinically significant effects.*9
Those with elevated blood sugar levels appear to have an increased requirement for vitamin E for a number of reasons, probably because oxidative stress is a major factor in raising blood sugar levels.*10 Vitamin E improves insulin action and exerts a number of beneficial effects that may aid in maintaining healthy blood sugar levels.*10,11,12
A Finnish study of 7,526 healthy people published in 1999 found a protective effect of vitamin E in maintaining healthy blood sugar levels.*11 Another study found that 800 IU of vitamin E per day diminished platelet aggregation (helping to maintain a healthy cardiovascular system) for those with elevated levels of blood sugar.*12 Further, several studies have shown that supplementing with high amounts (1,350 IU per day) of vitamin E improves glucose tolerance and sensitivity to insulin thus helping to normalize blood sugar levels.*10
Vitamin E is also critically important for immune function.* It protects the immune system from damage during times of oxidative stress and in the presence of abnormal cells.* In a study of healthy elderly subjects, supplementation of 800 IU of vitamin E for 30 days improved immune responsiveness, especially cell-mediated immunity, which otherwise tends to decline in function as we age.*13 Natural vs. Synthetic Vitamin E
The names of all forms of vitamin E begin with either “d” (the natural form) or “dl” (the synthetic form), referring to differences in chemical structure. The natural form is more absorbable (“bioavailable”) so less is required to be taken as a supplement than the synthetic form. All vitamin E supplements from Nature’s Life are the natural “d” form, which has been shown in recent studies on human subjects to have 50% or greater potency.14,15 Vitamin E potency is indicated by International Units (IU) which measure the biological value of vitamin E.
d-alpha-tocopherol (pure, unesterified) *
d-alpha-tocopheryl acetate (esterified) *
d-alpha-tocopheryl succinate (esterified)
dl-alpha-tocopheryl acetate *
Greater bioavailability of natural Vitamin E means that it is absorbed faster and more completely into the blood stream, and is retained longer.* More recent evidence demonstrates that the ratio of natural versus synthetic vitamin E bioavailability is 2:1 in the human liver and 4:1 across the human placenta.16,17,18 This finding is significant for pregnant women looking for the optimal form of vitamin E in their prenatal supplementation, as in Nature’s Life Prenatal Multiple formula. Most prenatal vitamins use the less well absorbed synthetic vitamin E.
Natural Vitamin E, moreover, has many other functions and benefits in human health, including inhibiting platelet aggregation, enhancing immune function and stabilizing membranes.*3,10,12 It is not yet clear whether synthetic vitamin E performs these functions as well as the natural form.
d-Alpha vs. other Tocopherols
Another important aspect of vitamin E involves its chemical structure. Synthetic vitamin E is only prepared in the alpha form, as in dl-alpha-tocopherol. Natural vitamin E can be found in alpha or in combination with other tocopherols, including beta, gamma and delta. The combination form is labeled “mixed” as in “natural mixed tocopherols.” The bulk of the research to date strongly suggests that the alpha form, whether synthetic or natural, is instrumental in supporting heart health.*19
Nearly all research showing positive health effects from Vitamin E supplementation have been done with the alpha tocopherol form. A group of researchers compared the gamma tocopherol form, the principal type found in the American diet, with alpha, the major type used in supplements. The researchers found that gamma tocopherol is necessary for the efficient antioxidant functioning of the alpha form.20 The researchers suggest that the current practice of supplementing only alpha tocopherol should be reconsidered.
Considering that this research is based only on a laboratory study, the issue of alpha versus gamma requires much more research before it can be fully understood. Until more is known, those that desire the gamma form can opt for vitamin E supplements containing significant amounts of gamma, beta and delta tocopherols, such as Nature’s Life Mega E 400.
The amount of vitamin E in the diet is largely dependent on the amount of polyunsaturated fats in the diet. These fats are found in vegetable oils, seeds, nuts, whole grains and fish. These fats are susceptible to oxidative damage in the body, and vitamin E is protective against this damage.* Fortunately, these foods contain substantial amounts of vitamin E themselves. Sunflower seeds, almonds, sweet potatoes, flax oil, spinach, and other green vegetables also contain significant amounts of vitamin E and all grains and legumes contain some. The gamma form is the most common tocopherol found in foods. Much vitamin E research shows that positive results require hundreds of units of total tocopherols per day (about 400 IU on average) - an amount impractical to obtain from food.*21
The Safe Supplement
All forms of vitamin E have an excellent safety record. A review of the literature concerning the safety of oral intake of vitamin E indicated that toxicity is extremely low and that even at doses as high as 3,200 IU/day, few side effects (and none serious) were reported.*22
Nature’s Life Natural Source Vitamin E
Although originally extracted from wheat, most natural vitamin E is now derived from soybeans. Nature’s Life primarily uses unesterified d-alpha tocopherol, the finest natural vitamin E available. Esterification is a chemical process that stabilizes the vitamin E to allow for different forms, such as Dry E. This process helps remove traces of the original source (soy). The shelf life is longer for esterified products, but some people prefer the more natural, unadulterated product.
Vitamin E supplements from Nature’s Life, with naturally-occurring mixed tocopherols, are available in 100 IU, 200 IU, 400 IU, 800 IU and 1,000 IU potencies. In addition, the following specialty products are offered:
- Super E Complex 200 IU: a combination of vitamin E, Lecithin and Wheat Germ Oil for added essential fatty acids to maintain a healthy cardiovascular system*
- Mega E 400 IU Complex: 400 IU d-alpha with 67 mg of added gamma, beta and delta tocopherols
- Dry E 400 IU: Dry, esterified and water-soluble for those sensitive to oil forms
- Pure E 400 IU: 100% natural Vitamin E with no soy oil or other filler.
National Research Council, Vitamin E Function & Metabolism Recommended Dietary Allowances, 1989;100. 2.
Garrison Jr. R, Somer E. Vitamin E Function, The Nutrition Desk Reference, 1995;84.
Knecht P, et al. Vitamin E in cancer prevention. Am J clin Nutr 1991;53(Suppl. 1):283S-286S.
Knecht P. Vitamin E and cancer; epidemiology. In: Sauberlich HE, Machlin LJ, eds. Beyond deficiency New York; NY Academy of Sciences 1992: p.269.
Stampfer MJ, Hennekens CH, Manson JE, Colditz GA, et al. Vitamin E consumption and the risk of coronary disease in women. N Engl J Med 1993;328:1444-9.
Rimm EB, Stampfer MJ, Ascherio A, Giovannucci E, et al. Vitamin E consumption and the risk of coronary heart disease in men. N Engl J Med 1993;328:1450-6.
Stephens NG, Parsons A, Scofield PM, et al. Randomised controlled trial of vitamin E in patients with coronary disease: Cambridge Heart Antioxidant Study (CHAOS). Lancet 1996;347:781-6.
Gey KF, et al. Inverse correlation between plasma vitamin E and mortality from ischemic heart disease in cross-cultural epidemiology. Am J Clin Nutr 1991;53:3263-3343.
Princen HMG, et al. Supplementation with low doses of vitamin E protects LDL from lipid peroxidation in men and women. Arterioscler Thromb Vasc Biol 1995;15:325-333.
Paolisso G, et al. Chronic intake of pharmacological doses of vitamin E might be useful in the therapy of elderly patients with coronary heart disease. Am J Clin Nutr 1995;61:848-852.
Knekt P, Reunanen A, Marniemi J, et al. Low vitamin E status is a potential risk factor for insulin-dependent diabetes mellitus. J Intern Med 1999;245:99-102.
Collette C, Pares-Herbute N, Monnier LH, Cartry E. Platelet function in type I diabetes: effects of supplementation with large doses of vitamin E. Am J Clin Nutr 1988;47:256-61.
Meydani SN, Barklund MP, Liu S, et al. Vitamin E supplementation enhances cell-mediated immunity in healthy elderly adults. Am J Clin Nutr 1990;52:557-63.
Acuff RV, Thedford SS, Hidiroglou NH, et al. Relative bioavailabity of RRR- and all-rac-alpha-tocopheryl acetate in humans: studies using deuterated compounds. Am J Clin Nutr 1994;60:397-402.
Cheng SC, Burton GW, Ingold KU, Foster DO. Chiral discrimination in the exchange of alpha-tocopherol stereoisomers between plasma and red blood cells. Lipids 1987;22:469-473.
Kiyose C, Muramatsu R, et al. Biodiscrimination of alpha-tocopherol stereoisomers in humans after oral administration. Am J Clin Nutr 1997;65:785-9.
Acuff RV, Dunworth RG, et al. Transport of deuterium-labeled tocopherols during pregnancy. Am J Clin Nutr 1998;67:459.
Gorden MJ, Campbell FM, Dutta-Roy AK. Alpha- tocopherol-binding protein in the cytosol of the human placenta. Biochem Soc Trans 1996;24:2025.
Reaven PD, Witztum JL. Comparison of supplementation of RRR-alpha-tocopherol and racemic alpha-tocopherol in humans. Thrombosis 1993:13:601-8.
Christen S, Woodall AA, Shigenaga MK, et al. Gamma-tocopherol traps mutagenic electrophiles such as NO(X) and complements alpha-tocopherol: physiological implications. Proc Natl Acad Sci 1997;94:3217-22.
Horwitt M. Data supporting supplementation of humans with vitamin E. J of Nutr 1991;121:424-9.
Bendich A and Machlin LJ. Safety of oral intake of vitamin E. Am J Clin Nutr 1988;48:612-9.