Statements on Vitamin C and the Common Cold in Major Infectious Disease Textbooks

This document collected comments on vitamin C for treating the common cold in major textbooks of infections diseases. Serious errors in the Chalmers review (1975) and in the analysis of the Karlowski-Chalmers controlled trial (1975) have been described:https://zenodo.org/records/18377351https://zenodo.org/records/18376955 https://zenodo.org/records/18376995 Several consecutive editions of two major textbooks on infectious diseases referred to the Karlowski trial in no uncertainterms: "Many participants correctly surmised from the taste of the contents of the capsules used whether theywere receiving vitamin C or a placebo" (Gwaltney 1979, 1985, 1990, 1995), and "It is most probable that the reportedbenefits are a result of statistical artifacts and placebo effect due to poor study design rather than specificpharmacologic drug effects" (Cherry 1987, 1992, 1998). The attached extracts demonstrate that the two papers (1975) led to misleading description of vitamin C and the common cold in textbooks for over a decade. Gwaltney In: Mandell, Douglas and Bennett's Principles and Practice of Infectious Diseases, 4th edition (1995) stated, p564-565: The ingestion of large doses of vitamin C has beenwidely used as a preventive or therapeutic measure for colds.In some instances, controlled studies have shown a modest beneficialeffect of vitamin C for colds. However, a careful analysisof the studies had indicated that a placebo effect could no beruled out. In one study, many participants correctly surmisedfrom the taste of the contents of the capsules used whether theywere receiving vitamin C or a placebo [61].Ref: 61. Chalmers TC. Effects of ascorbic acid on the common cold. An evaluation of the evidence. Am J Med. 1975:58:532. Liu In: Infectious Diseases A Modern Treatise of Infectious Processes, by Paul D Hoeprich and M Colin Jordan, 4th edition (1989), p.292-293: There is no proof of any curative value from the many proprietary remedies containing vitamins (including vitamin C), bio-flavinoids, multiple analgesics, or antihistaminics in the treatment of the common cold.Ref: Chalmers TC: Effects of ascrobic acid on the common cold: An evaluation of the evidence. Am J Med 58:532, 1975 Cherry In:Textbook of Pediatric Infectious Diseases Edition 4 Volume 1 (1998), by Ralph D. Feigin and James D. Cherry (1998), p.131: ... during the last 15 years, there have been several large controlled trials inwhich vitamin C and placebo preparations have been usedto prevent and to treat colds.... [66] In some of these studies adegree of benefit was reported, whereas in others noefficacy was noted. It is most probable that the reportedbenefits are a result of statistical artifacts and placebo effectdue to poor study design rather than specific pharmacologicdrug effects.Ref: 66. Karlowski, T. R., Chalmers, T. C, Frenkel, L. D., et al.: Ascorbic acid forthe common cold: A prophylactic and therapeutic trial. J. A. M. A.232:1038-1042, 1975.