Vitamin C
Vitamin C can be found in citrus fruits, melons, and tomatoes; adult males should get 90 milligrams a day, while women should aim for 75 milligrams. Some people take it to protect against the common cold, but a review of 30 clinical trials found no evidence that vitamin C prevents colds. There are some exceptions though: It may reduce the risk in people who live in cold climates or experience extreme physical stress, such as running marathons. Smokers may need extra vitamin C. Still, most people will be better off with these ways to prevent the cold and flu. Studies haven’t backed up claims that high doses of vitamin C can fight cancer and heart disease.
Bottom line: Most people don’t need C supplements.
