As discussed earlier, although vitamin E has been hypothesized to prevent myocardial infarction at the clinical level, only one of the four published large-scale, randomized, double-blind clinical secondary intervention studies that tested the ability of vitamin E to do this has been supportive of that hypothesis. This secondary prevention trial using 400 or 800 international units (IU) (268 or 567 mg)/day of RRR-α-tocopherol, was strongly positive (Stephens et al., 1996). The other three, one carried out in a group of high-risk cigarette smokers and using 50 mg/day of all-rac-α-tocopherol (ATBC Cancer Prevention Study Group, 1994) and two carried with groups of high-risk cardiovascular disease patients and using 300 mg/day of all rac-α-tocopherol (GISSI-Prevenzione Investigators, 1999) or 400 IU (268 mg)/day of RRR-α-tocopherol (HOPE Study Investigators, 2000), were neutral, with respect to coronary heart disease.

The limited clinical trial evidence precludes recommendations for higher vitamin E intakes at this time. Thus, adults ages 51 years and older appear to have the same vitamin E requirement as younger adults.

There is no evidence that the aging process impairs vitamin E absorption or utilization. Therefore, for the age group 51 years and older an EAR of 12 mg (27.9 µmol)/day of α-tocopherol, the same as younger adults, is warranted.

The RDA for vitamin E is set by assuming a coefficient of variation (CV) of 10 percent (see Chapter 1) because information is not available on the standard deviation of the requirement for vitamin E. The RDA is defined as equal to the EAR plus twice the assumed CV to cover the needs of 97 to 98 percent of the individuals in the