“Vitamin C prevents or cures the common cold.”

The widespread belief that regularly taking vitamin C can prevent or cure the common cold largely stems from the advocacy of Nobel Prize-winning chemist Linus Pauling. In 1970, Pauling published "Vitamin C and the Common Cold," a book that popularized the idea that high doses of vitamin C could significantly reduce the incidence and severity of colds. His influential claims, based on his personal experiences and interpretations of some studies, led to a dramatic increase in public consumption of vitamin C supplements, establishing a deeply entrenched misconception.

Despite Pauling's assertions, extensive scientific research has consistently shown that routine vitamin C supplementation does not prevent the common cold in the general population. Multiple studies and meta-analyses have found that taking vitamin C daily does not reduce the likelihood of catching a cold. While some evidence suggests that regular intake might modestly shorten the duration of cold symptoms by about 8% in adults and 14% in children, or slightly lessen their severity, it is not a cure and offers no benefit if taken only after symptoms have begun. An exception exists for individuals under extreme physical stress, such as marathon runners, where vitamin C may reduce the risk of catching a cold by about half.

The enduring popularity of this myth can be attributed to several factors. Beyond Pauling's celebrity status, vitamin C is indeed an essential nutrient vital for overall health and proper immune function, supporting tissue repair, collagen production, and acting as an antioxidant. This fundamental role in immunity leads many to assume that higher doses will provide greater protection against illness. However, the human body can only absorb a certain amount of vitamin C, and any excess is typically flushed out, meaning expensive supplements often result in "very expensive urine" rather than enhanced cold protection.