Steve Bui, M.S.
I think it is safe to say we have all heard it at some point in our lives. I remember as a child, my mother telling me on several occasions. In fact, whenever I had the slightest cough, she would squeeze lime juice into everything I ate. Whether it is your loving family, friend, television advertisement, or newspaper, the general consensus has always been that if you are feeling sick, or have flu-like symptoms, increasing your vitamin C intake will help you recover faster and prevent future cases… Is that so?
Let’s start with a basic review of Vitamin C, also known as ascorbic acid. Vitamin C can be found in a variety of foods, including citrus fruits, broccoli, and tomatoes. Vitamin C plays many roles in the human body such as growth and repair of tissues, production of collagen, repairing and maintaining bones, and simply as a natural antioxidant. Vitamin C has also been shown to help increase dietary absorption of iron which plays an important role in red blood function. The recommended dietary allowance of vitamin C is approximately 75-90 mg for adults. Vitamin C deficiencies are generally very rare and even less so in developed countries.
Now that we understand a bit about vitamin C, it would be important to understand how vitamin C became the go-to remedy for common colds. In 1970, a well renown scientist (winner of two Nobel Prizes) named Linus Pauling published a book reporting that vitamin C prevents and alleviates common colds. He supported his claims with several conducted studies, which now are considered somewhat flawed. More recent studies show vitamin C has little or no effect in preventing the common cold, and any effects it has are due to nonspecific effects on the immune system. It must also be noted that in most studies the supplementation dose of vitamin C is in the 1-2 gram range, which means that subjects were ingesting approximately ten times the amount of the daily dose but still the results were inconclusive.
It would seem at this point, it is difficult to say with 100 percent conviction that vitamin C plays absolutely no role in the prevention of the common cold without more detailed studies; however, it is safe to say it is not as effective as many believe.
- Hemila H. (1997) “Vitamin C Supplementation and the Common Cold Was Linus Pauling Right or Wrong?” Internat. J. Vit. Nutr. Res. 67, 329-335.
- Tyrrell, D.A.J., Craig,J.W., Meade T.W., and White t. (1977) “A trail of ascorbic acid in the treatment of the common cold.” Br. J. Prev. Soc. Med. 31, 189-191.