Study Suggests Going Heavier on Vitamin C

Some 200 milligrams of vitamin C a day, about three times the current recommended daily allowance, seems to be the most healthful dose for men, according to new research by National Institutes of Health.

The study, reported Tuesday in the Proceedings of the National Academy of Sciences, involved just seven patients. But it was the first that measured the body’s absorption, distribution and excretion of multiple doses of vitamin C in healthy people who were hospitalized so doctors could control everything they ate.

“Eating five fruits and vegetables a day will easily provide 200 milligrams,” said study author Dr. Mark Levine. And the message for doctors: “They should ask patients who complain of fatigue or irritability what they eat. If their diet is all fast food, they may be deficient in vitamin C.”

Levine hospitalized seven healthy men ages 20 to 26 for up to six months, restricting the vitamin C in their diets but providing different doses in pills.

When patients ate just 30 milligrams, they felt tired and irritable. At 200 milligrams, their tissues were completely saturated with the important vitamin. Doses of 500 milligrams and higher were completely excreted in urine. At 1,000 milligrams, some patients experienced side effects, including high levels of uric acid that can lead to kidney stones.

The National Academy of Sciences sets the RDAs of nutrients and picked 60 milligrams many years ago as enough to prevent people from getting scurvy, a nutritional disease now seldom seen in this country. Scientists have not announced plans to change the RDA.