Vitamin C and common cold.

To the Editor.—My book, Vitamin C and the Common Cold was reviewed in THE JOURNAL by Franklin C. Bing (215:1506, 1971). I do not object to the expression by the reviewer of his opinions, However, it is essential that the several untrue and thoroughly misleading statements that he makes be corrected. I do not state that ascorbic acid is a completely harmless chemical. I describe it as natural, essential food that is nontoxic, and has far fewer side reactions than aspirin and other common cold medicines. I do not recommend doses of from 1 to 10 gm daily throughout life. Instead, I say that there is evidence that some people remain in very good health, including freedom from the common cold, year after year through the ingestion of only 250 mg of ascorbic acid per day, that the requirements of a few people for ascorbic acid may be expected to be even smaller', and for others larger. I present in my book a careful analysis of the controlled trials of ascorbic acid that have been published, and point out that several of these investigations have shown, with statistical significance at the confidence level of 95% or higher, that ascorbic acid has value in decreasing both the incidence and the severity of the common cold. I emphasize that I stated in my book that no large-scale study has been carried out to show to what extent the regular ingestion of ascorbic acid in large amounts is effective. The reviewer misquoted me, by omitting the statement about regular ingestion in large amounts. In fact, large-scale studies involving the regular ingestion of ascorbic acid in small amounts have been carried out, and have given statistically significant results, showing that even these small amounts are effective in preventing and ameliorating the common cold and associated infections. A correct review would have included mention of the fact that several good controlled studies have been made of the effect of ascorbic acid in amounts of about 200 mg/ day or 1,000 mg/day administered regularly to subjects beginning before they had contracted colds, with other subjects receiving a placebo. It has been found that the subjects given ascorbic acid had fewer colds than the placebo subjects, that the severity of individual colds was less, and that these results were statistically significant. The reviewer's statement that the efficacy of ascorbic acid in any dosage form has not been proved is false. Results with high statistical significance obtained by reliable medical investigators in several carefully controlled studies have proved the efficacy of ascorbic acid administered over a period of time to subjects exposed to cold viruses in the normal way in decreasing the incidence and severity of the common cold. These results have not been contradicted by statistically significant negative results in a single controlled test carried out under similar circumstances. The review of my book misrepresents the facts completely. LINUS PAULING, PnD Stanford, Calif