An estimated 70 percent of the U.S. population uses dietary supplements
at least occasionally and 40 percent use supplements on a regular
basis. Vitamin E and vitamin C are among the most commonly used
supplements.
Contrary to the belief some have, there are many studies that show
vitamins E and C are safe for the general population. Why? Because
these nutrients supply antioxidants for the protection against free
radical damage. Thus, in light of these supposed benefits, many
consume quantities of both vitamins E and C far beyond the recommended
daily allowances (RDA).
Researchers tend to support the consensus of published studies
that it is safe to consume:
- Vitamin E doses up to 1,000 mg/d
- Vitamin C doses up to 2,000 mg/d
Moreover, compared with the previous RDA, new recommendations for
vitamin E have increased by 50 percent for men and almost 100 percent
for women, while recommendations for vitamin C have increased by
25 percent for women and 50 percent for men.
Low Intakes of Vitamins E and C
Low intakes of these antioxidants, however, may increase the risk
of certain chronic diseases and accelerate several indicators of
the aging process. Such effects may be partially due to inadequate
protection of tissues against oxidative damage from free radicals.
On the other hand, researchers have not found any consistent pattern
of evidence to support concerns over serious adverse effects of
taking quantities of vitamins E and C well above what is recommended.
So Are These Vitamins Really Safe?
Vitamin E and C supplements are widely used in the United States
(and other industrialized countries). In relation to dosage concerns
and the health implications of such, it is important to understand
that the upper limits for using these vitamins were designed to
protect the most sensitive individuals in the general population;
upper limits were not intended to apply
to the most sensitive persons, but rather the healthy general population.
Additionally, healthy people are not recommended to "routinely"
take vitamin E and C in amounts beyond the upper limits.
American
Journal of Clinical Nutrition, April 2005;89(4)4: 736-745
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