Introduction

The Antioxidant Panel of the Food and Nutrition Board, Institute of Medicine, National Academy of Sciences (NAS), announced in 2000 the new recommended dietary allowances (RDA) for Vitamin C and E. For Vitamin E, the new RDA for both men and women has been raised to 15 mg, up from 8 mg for men and 6.4 mg for women. The newly established upper level, assuming the source is from supplementation, is as high as 1,000 mg of Vitamin E (alpha-tocopherol per day). This is equivalent to roughly 1,500 IU of "d-alpha-tocopherol." For Vitamin C, the new RDA is 90 mg for men and 75 mg for women, up from 65 mg. The newly established upper limit for Vitamin C is 2,000 mg per day.


Vitamin E

In view of the mounting evidence that Vitamin E is a powerful antioxidant with significant health benefits, the NAS panel virtually doubled their old recommendation to 15 mg of d-alpha-tocopherol (the natural form of Vitamin E and the basis for the new RDAs) per day for both men and women. 

The old RDA had rated natural Vitamin E as being only 36% more active than the synthetic form. This report confirms that the difference is much greater. In fact, the NAS panel has determined that natural Vitamin E is twice as potent as the synthetic version.

The form of Vitamin E that is best used and retained by the body is the RRR-tocopherol (alpha). In the process of making synthetic Vitamin E from petroleum chemicals, fully one half of synthetic Vitamin E is in the form of tocotrienols, and beta-, gamma- and delta-tocopherol, all of which the body does not recognize and preferentially excretes. On the other hand, 100% of natural-source Vitamin E, purified from plant sources, is in the RRR-tocopherol (alpha) form recognized and used by the body.

Another highlight of the report for Vitamin E includes the establishment of an upper intake level (UL). This UL for Vitamin E is 1,000 milligrams daily. This is equivalent to approximately 1,500 international units of natural-source Vitamin E or 1,100 IU of synthetic Vitamin E. The difference in limits for natural-source and synthetic forms of Vitamin E underscores the importance of the NAS finding that synthetic Vitamin E contains compounds with no Vitamin E activity. The UL also establishes that Vitamin E is safe in amounts much greater (67 times) than even the new RDAs.

There have been many studies showing the benefits of Vitamin E. The following two will demonstrate some of them, as well as give you some insight into the reasons on which the NAS based their decision to increase the RDA and establish such a high upper limit.

In our first study, which was published in Lancet in 1996, 2002 patients with angiographically proven coronary atherosclerosis were enrolled in a Vitamin E supplementation program and followed for a median of 510 days. These patients were given alpha-tocopherol capsules containing 800 IU a day for the first 546 days and 400 IU daily for the remainder. Results showed that alpha-tocopherol treatment substantially reduced the rate of non-fatal MI (heart attacks), with beneficial effects apparent after 1 year of treatment. 

In the second study, published in Journal of the American Medical Association (JAMA), in 1995, 156 men aged 40-59 with previous coronary artery bypass graft surgery were supplemented with 100 IU of Vitamin E per day and compared to those men whose intake was less than 100 IU per day. After the treatment, subjects receiving 100 IU demonstrated less coronary artery lesion progression than did subjects with intake of less than 100 IU per day, as determined by angiography.

Studies determining the efficacy between various forms of Vitamin E are less clear, especially as it relates to alpha- vs. gamma -Tocopherol. Some studies have suggested that gamma-Tocopherol is more effective, while others show that a mixed blend of alpha- and gamma- appears to be the best. Until more research is available, it is clear that the standard form of Tocopherol should be alpha-Tocopherol. Studies have already determined that Vitamin E derived from natural source ("d"form) is better than synthetic form ("dl"form).