Calculating Antioxidants?

Exactly how many antioxidants should be consumed daily to get the full benefit of them? Is it based on age, weight, height, etc? If so, how do I figure out how much I need?

– November 11, 2014

Originally published March 24, 2009. Updated November 11, 2014.

There is no simple formula you can use to individualize the amount of supplemental antioxidants you need based on such considerations as age, weight, height or other characteristics. However, many good quality multivitamin products provide adequate antioxidants for most people. Here are my general recommendations:

  • Vitamin C: 250 mg daily. This amount is more than adequate to saturate the body’s tissues and provide protection against cancer, heart disease and other chronic illnesses. You can take up to 1,000 mg extra C a day if you have additional oxidative stress in your life, such as an illness, or if you are exposed to a lot of pollution or secondhand smoke.
  • Vitamin E: 400 IUs a day of mixed natural tocopherols, or at least 80 mg of mixed tocopherol and tocotrienols. Always choose natural vitamin E (d-alpha tocopherol with mixed tocopherols) and avoid the synthetic form (dl-alpha-tocopherol). The best brands will also include mixed tocotrienols, the other components of natural vitamin E. I take vitamin E at lunch or dinner.
  • Selenium: 80-200 micrograms (mcg) a day. This trace mineral has antioxidant and anticancer properties. Because selenium and vitamin E facilitate each other’s absorption, I recommend taking them together. Doses above 400 mcg of selenium a day may not be healthy.
  • Vitamin A or mixed carotenes: 15,000 IUs a day. Use natural forms of mixed carotenoids such as alpha- and gamma-carotene along with beta-carotene, which are easily found in health food stores. Read the label to make sure products contain lycopene, the red pigment in tomatoes that helps prevent prostate cancer, and lutein, which protects against cataracts and macular degeneration. Better brands will include other important carotenoids such as astaxanthin, zeaxanthin, phytoene and phytofluene.

Always take supplements with meals to enhance absorption and reduce the risk of stomach upset. Just bear in mind that the antioxidant supplements I recommend are your backstops and insurance against falling short of these same nutrients in your daily diet, and are not a substitute for good nutrition. Be sure to eat a variety of organic fruits and vegetables across the color spectrum to get a full complement of antioxidants. As you get older, if you are exposed to toxins or if your diet isn’t as good as it should be, strive to get additional antioxidants from foods. To learn more about your specific needs, or if you have a new health concern, weight change or some other variation in your physical status, consult my Vitamin Advisor.

Andrew Weil, M.D.

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