Your Questions Answered,  By Our Patron Roger French


QUESTION:   A friend is taking high doses of vitamin C and is chewing vitamin C tablets frequently throughout the day, the total daily dose being six grams (6,000 mg). She is not, of course, cleaning her teeth after each tablet, nor does she rinse her mouth with water. She has had a lot of tooth decay, which at times has required extractions. Is it likely that the vitamin C is damaging the enamel and contributing to the decay? 


Vitamin C in supplements is usually in its acid form – ascorbic acid – which is capable of damaging tooth enamel.

The professor of oral pathology at Tufts University, Boston USA, Dr. John Giunta, says that chewable vitamin C has the potential to damage teeth. In the Journal of the American Dental Association, Autumn 1983, he explains that chewable vitamin C can make the saliva acidic enough to cause the calcium in tooth enamel to form calcium citrate complexes, leaving the enamel destroyed.

Dr Giunta described the case of a 30-year-old woman who had chewed three tablets of megadose vitamin C every day for three years and had severe enamel erosion. His advice is that safe doses of vitamin C can be taken without using the chewable form.

Another dental opinion is that dental erosion from chewable vitamin C will rarely be a problem if you follow the recommended dosage. On the other hand, if you take very large doses of chewable vitamin C for a long period of time, you might be faced with severe dental erosion. This dentist recommends that we can obtain adequate vitamin C from fruits, vegetables and supplements in pill or powder form.

A wholistic dentist, who I know personally and who uses chewable C himself, believes that it is fine to chew vitamin C once or twice per day provided the mouth is rinsed immediately after with a glass of water.

Further, he says, even if a lot of chewable C is being taken, the immediate rinsing should still prevent problems with the enamel. If there is no rinsing, the enamel could etch, but not enough to cause rampant decay. If there is rampant decay, there are probably other causative factors at work.

The six grams a day that your friend is taking is a huge amount, and she doesn’t do any rinsing. Based on the above opinions, this huge amount might well be the cause of the problem.