It’s advice you’ve probably given or received at least once. If someone feels like they’re getting a cold, it seems natural to suggest that they take some vitamin C, whether in the form of an orange, a glass of juice, or a vitamin C supplement. Perhaps, anecdotally, it seems to have worked for you in the past, or maybe it’s just what your family does whenever someone starts to sniffle.
Yet despite what supplement manufacturers would have you think, there is little research-based evidence that vitamin C, even in mega-doses, can prevent or cure the common cold. In most cases, there is no benefit to taking vitamin C after a cold has already begun. Neither the Food and Drug Administration, the American Medical Association, nor the American Dietetic Association recommends vitamin C supplementation to prevent or treat colds.At best, it seems that people who take a large dose of vitamin C as a preventative measure (up to 1000 mg per day) may experience a slightly shorter duration of cold symptoms, and those symptoms may be slightly less severe. A large meta-analysis of 29 placebo-controlled trials found that daily vitamin C supplementation did not significantly reduce the incidence of colds, nor was it an effective treatment method. However, vitamin C did appear to (modestly) reduce their duration by 8% in adults and 14% in children.
Vitamin C supplements owe much of their popularity to the Nobel Prize-winning American chemist Linus Pauling. In the 1960s, Pauling shared his experience of taking large doses of vitamin C, which he said made him feel “livelier and healthier.” He further emphasized his claims in his best-selling book Vitamin C and the Common Cold, first published in 1970, which led to skyrocketing sales of vitamin C supplements.
Yet although there is little reason to view vitamin C as a cure or treatment for the common cold, that doesn’t mean you should stop taking it. In doses up to 1 gram per day (or possibly more), vitamin C is considered safe. The micronutrient is a natural antioxidant that is also critical for tissue growth, collagen synthesis, and wound healing.
More about vitamin C:
- Besides citrus fruits, you’ll find high levels of vitamin C in leafy greens, red and green peppers, strawberries, tomatoes, and watermelon. Eating just one or two foods rich in vitamin C should help you easily meet the recommended daily allowance of around 90 milligrams for men and 75 mg for women.
- Taking too much vitamin C (at least 2 g per day) from supplements may result in an upset stomach. Large doses are not recommended during pregnancy. People with kidney problems should avoid vitamin C supplementation.
- At least one group responds better to vitamin C than others. Daily vitamin C supplementation may help prevent colds among people who experience short periods of strenuous physical stress, such as soldiers and marathon runners.
- Want to stay as healthy as possible this cold season? Sadly, there’s no cure for the common cold, although getting plenty of rest and drinking fluids will help your body fight the virus. For prevention, eating a balanced diet (including getting enough vitamin C) is undoubtedly important, as are drinking enough fluids, getting sufficient sleep, and washing your hands regularly.
