{"id":23831,"date":"2026-08-20T10:44:40","date_gmt":"2026-08-20T06:44:40","guid":{"rendered":"https:\/\/medscriptum.org\/?p=23831"},"modified":"2026-08-20T10:51:54","modified_gmt":"2026-08-20T06:51:54","slug":"is-vitamin-c-really-effective-for-colds-what-science-says-about-the-popular-myth","status":"publish","type":"post","link":"https:\/\/medscriptum.org\/en\/is-vitamin-c-really-effective-for-colds-what-science-says-about-the-popular-myth\/","title":{"rendered":"Is Vitamin C really effective for colds? What science says about the popular myth"},"content":{"rendered":"

As winter approaches,<\/span> aggressive marketing of vitamin C begins in pharmacies and supermarkets as a shield against colds.<\/span> Although taking high doses of vitamin C during virus season is a deeply entrenched practice among the public,<\/span> modern scientific research shows that its real efficacy is far more modest.<\/span><\/p>\n

This popular belief traces its roots back to 1970,<\/span> when American chemist and two-time Nobel laureate Linus Pauling published a dedicated book.<\/span> Despite the fact that Pauling was neither a nutritionist nor an infectious disease specialist,<\/span> he advised the public to take between 1,<\/span>000 and 2,<\/span>000 milligrams of vitamin C daily to maintain health and prevent colds.<\/span> His claim relied on a placebo-controlled study conducted on children in the Swiss Alps,<\/span> which scientists today consider methodologically flawed.<\/span> Nevertheless,<\/span> the book boosted vitamin C sales to unprecedented levels.<\/span><\/p>\n

Do megadoses actually work?<\/span> Large-scale meta-analyses conducted in 2013 and 2023,<\/span> combining data from thousands of individuals,<\/span> revealed that vitamin C does not reduce the risk of developing a cold.<\/span> Furthermore,<\/span> starting to take it after cold symptoms appear yields no therapeutic benefit whatsoever.<\/span> The only minor benefit is observed when a person takes the vitamin regularly,<\/span> even prior to illness \u2014 in this scenario,<\/span> the duration of severe symptoms is reduced by an average of 10\u201315% (for instance,<\/span> a 5-day severe cold might be shortened by 12 hours),<\/span> though it has no effect on mild symptoms at all.<\/span> The sole exceptions are professional athletes and military personnel,<\/span> in whom the supplement showed a small positive effect.<\/span><\/p>\n

Regarding dosage,<\/span> the daily requirement for an adult in most countries is approximately 45 milligrams,<\/span> which can easily be obtained from half an orange or a few pieces of broccoli.<\/span> Long-term intake of more than 1,<\/span>000 milligrams of vitamin C per day increases the risk of side effects such as:<\/span> gastrointestinal issues (diarrhea,<\/span> nausea),<\/span> kidney stone formation,<\/span> and excessive iron absorption (which is particularly dangerous for individuals with undiagnosed hemochromatosis).<\/span> Additionally,<\/span> high doses may interfere with chemotherapy and cholesterol-lowering medications (statins).<\/span><\/p>\n

Consequently,<\/span> doctors advise avoiding self-prescribed supplements and consulting a specialist regarding dosages,<\/span> especially given that severe vitamin C deficiency affects a very small portion of the population (less than 4%) in the developed world.<\/span><\/p>\n

MedicalXpress<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

As winter approaches, aggressive marketing of vitamin C begins in pharmacies and supermarkets as a shield against colds. Although taking high doses of vitamin C during virus season is a deeply entrenched practice among the public, modern scientific research shows that its real efficacy is far more modest. This popular belief traces its roots back […]<\/p>\n","protected":false},"author":2,"featured_media":23830,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1594,1665,1587,1657],"tags":[6808],"class_list":["post-23831","post","type-post","status-publish","format-standard","has-post-thumbnail","category-news","category-public-health","category-research","category-science","tag-vitamin-c"],"acf":[],"_links":{"self":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts\/23831","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/comments?post=23831"}],"version-history":[{"count":1,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts\/23831\/revisions"}],"predecessor-version":[{"id":23834,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/posts\/23831\/revisions\/23834"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/media\/23830"}],"wp:attachment":[{"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/media?parent=23831"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/categories?post=23831"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/medscriptum.org\/en\/wp-json\/wp\/v2\/tags?post=23831"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}