Vitamin C also helps in the synthesis of collagen, which holds together tissues and is a structural component of gums and skin. A severe deficiency of vitamin C leads to a health condition called scurvy<\/a>, where the body produces insufficient collagen and can\u2019t hold tissue together. Eventually, the gums cannot hold onto teeth and they fall out, and blood vessels break down, causing internal bleeding.<\/p>\n Humans cannot synthesise vitamin C. We must take it in through our diet<\/a>. Most of our vitamin C comes from vegetables (about 40%), fruits (19%) and from vegetable or fruit juices (29%).<\/p>\n Chemically, the vitamin C in supplements is identical to the vitamin C in food. Your body cannot tell the difference. <\/p>\n Vitamin C in supplements and food are identical. What is missing in supplement forms of vitamin C is the fibre, flavonoids, other vitamins, minerals and phytochemicals that come with food, and that may work together with vitamin C. <\/p>\n These other compounds help with absorption, provide complementary antioxidants, and together with vitamin C, provide health benefits that the vitamin by itself does not. <\/p>\n Historically, sailors<\/a> often had a very limited diet and were often struck down with scurvy. But if you have a balanced diet, you don\u2019t need vitamin C supplements. <\/p>\n What does vitamin C treat and not treat?<\/p>\n Common cold<\/p>\n Vitamin C has been promoted as a way to boost the immune system. It\u2019s widely considered as a way to prevent and treat the common cold and flu. <\/p>\n However, results from a review of all the evidence<\/a> has shown regular supplementation of 200 mg or more vitamin C does not reduce the incidence of the common cold. <\/p>\n Regular vitamin C supplement does reduce the duration, and at doses greater than 1,000 mg or more, could reduce the severity<\/a> of common cold symptoms. <\/p>\n When vitamin C is used for treating common colds and only taken at the start of cold symptoms, it does not affect the duration and severity<\/a>. Some studies have a shown very limited benefit when taken daily before getting sick, but the benefit was very small. Overall, the authors concluded routine supplementation with vitamin C is not worthwhile.<\/p>\n Heart disease and stroke<\/p>\n Research<\/a> has shown vitamin C supplementation does not change the risk of a range of cardiovascular diseases including heart attack (myocardial infraction), stroke or angina.<\/p>\n One study<\/a> found vitamin C supplementation at more than 200 mg daily may lower systolic blood pressure (the top number in a reading) by around 4 mmHg and diastolic blood pressure (the lower number) by around 2 mmHg. These are very small changes. <\/p>\n These effects are comparable to regular aerobic exercise and may not be clinically meaningful compared to treatment with conventional medicine<\/a>, which generally lowers systolic blood pressure by at least 12 mmHg. <\/p>\n Cancer<\/p>\n There are consistent results from multiple studies that show vitamin C supplementation is unable to prevent cancer, including for gastrointestinal<\/a>, lung<\/a>, breast, prostate and colorectal<\/a> cancers. <\/p>\n Is it possible to take too much vitamin C?<\/p>\n The Recommended Daily Intake (RDI) of vitamin C for adults is 45 mg per day<\/a>. You can get that from a single small glass of orange juice<\/a>. <\/p>\n The tolerable upper intake level<\/a> of vitamin C is 2,000 mg daily for adults.<\/p>\n Vitamin C is water-soluble and gets excreted in urine, so the body cannot store it. This means mega-dosing does not provide any benefit, and may in fact cause health problems.<\/p>\n At high doses (above 2,000 mg daily), vitamin C may cause mild to serious side effects<\/a>. Too much is known to cause diarrhoea, nausea and abdominal cramps. It can also contribute to the formation of kidney stones<\/a> in men, but not women. <\/p>\n![\"An](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/03\/file-20260311-72-abi93i.jpg\")
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\n Diana Polekhina\/Unsplash<\/a><\/p>\n