Dear Dr. Walt,
Doesn’t vitamin C help prevent cataracts?
—Supplement Supporter in Connecticut
Dear Ascorbic Acid Advocate,
Studies have shown that Vitamin C from foods does help.
One study found that those with the highest intakes were 19% less likely to have nuclear cataracts and were 33% less likely to experience progression of cataracts over the next 10 years.
As far as Vitamin C supplements, most but not all studies suggest that vitamin C from supplements also helps prevent cataracts, but only if taken long-term (10 years or more).
Studies shorter than 10 years have shown no benefit.
Other researchers have discovered that the daily intake of vitamin C needed to saturate the eye is about 150 mg to 250 mg per day.
And, they’ve established that not only is higher-dose vitamin C NOT helpful, the higher doses may be harmful, even increasing your risk of a cataract.
The experts at ConsumerLab.com say that the bottom line is this: Vitamin C may reduce the risk of developing cataracts if taken for more than 10 years at a moderate dose of 60 to 250 mg a day, but more than this is potentially harmful.
And, I always recommend food sources over supplements. Fruits with the highest sources of vitamin C include:
- citrus fruits and
- juices, such as
- orange and
- cranberries, and
© Copyright Walter L. Larimore, M.D. 2016. This blog provides a wide variety of general health information only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment from your regular physician. If you are concerned about your health, take what you learn from this blog and meet with your personal doctor to discuss your concerns.