Too Much of This Vitamin Could Make You Really Sick

But it’s advertised as a miracle cure
Vitamin C


Can you have too much of a good thing?

“Take your vitamins” is an age-old adage that a generation of mothers has ingrained into our collective psyche, and with over 50 percent of Americans taking some kind of supplement, it looks like most of us are heeding mom’s advice. But when it comes to vitamins, it’s possible to have too much of a good thing, especially when talking about everyone’s favorite nutrient — vitamin C.

Naturally found in everything from orange juice to broccoli, vitamin C — the recommended daily allowance for which is about 60 milligrams for adults (the amount in a half-cup of orange juice) — fortifies the immune system, protects against cardiovascular and skin disease, and also battles against inflammatory free radicals. Since vitamin C is easily attainable through the food we eat, only six percent of Americans are deficient, but despite this fact, vitamin C tablets, powders, and fruit chews line the walls of pharmacies and supplement stores.    

America’s obsession with vitamin C is no accident. Linus Pauling, a recipient of the Nobel Prize in chemistry, introduced mainstream culture to the wonders of vitamin C in 1966 after he received a letter from biochemist Irwin Stone arguing that if Pauling (who was then 65) took 3,000 milligrams of vitamin C he would, “live not only 25 years longer, but probably more.” Pauling took Stone’s advice, felt better, and eventually upped his intake to 18,000 milligrams a day — more than 300 times the recommended daily intake. In 1970 Pauling published a paper that recommended taking 3,000 milligrams of vitamin C a day (or 50 times the RDA) to eliminate the common cold and increase longevity. Later in his career, Pauling even claimed that vitamin C would reduce risks of cancer. (He died of prostate cancer at the age of 93.)

Countless studies have contrasted Pauling’s claims that vitamin C can reduce risks of cancer and instances of the common cold, saying that any quantity above 200 milligrams is excreted through urine, but research now argues that too much vitamin C is not only ineffective, but can be detrimental to health. A 1998 article in The New York Times cited evidence that as little as 500 milligrams of vitamin C a day could have pro-oxidant effect, damaging genetic material and DNA. Dr. Victor Herbert, professor of medicine at the Mount Sinai School of Medicine in New York, was quoted in the article saying that, “The vitamin C in supplements mobilizes harmless ferric iron stored in the body and converts it to harmful ferrous iron, which induces damage to the heart and other organs.” A more recently published study in JAMA Internal Medicine details a strong connection between kidney stone formation and use of vitamin C supplements.


While there are few side effects from eating foods naturally rich in vitamin C, taking thousands of milligrams worth of supplements may have some adverse effects.