Everybody knows vitamin C; it can be found organically in the fruits and vegetables we eat, and even in some food of animal origin, although in lower quantities. Vitamin C is one of the most popular supplements. It is commonly used as an immune booster, and has a key role in several biological processes as well. 

Multiple studies have proved that a higher dose of vitamin C can help prevent several illnesses, and, as it turns out, it can aid us in predicaments we would never expect. (1, 2) 

Can vitamin C be really used to treat the common cold? 

Vitamin C has been recommended to treat the common cold and other viral infections for decades, even though there’s a lot of controversy surrounding its efficacy. Linus Pauling argued in his book in the 70s that large doses of vitamin C can prevent infections, and the duration of illness can also be reduced through supplementation. 

Later studies found that while the duration of illness can indeed be reduced through vitamin C supplementation, it only reduces the incidence of the common cold in people who exercise regularly or do physical work – in their case the instances of disease drop by half. (4) Larger doses of vitamin C supplementation, i.e. a daily intake of 1000-2000 mg was better at reducing the duration of the common cold than lower doses. 

Effects on the cardiovascular system 

Vitamin C has several beneficial effects on the cardiovascular system as well. This has been studied for decades. As one of the main antioxidants in the body, vitamin C contributes to the blood vessels’protection against oxidative stress, improves circulation and decreases blood pressure. (5, 6) (7) 

With optimal vitamin C supplies, the risk of several cardiovascular diseases decrease significantly. A study found that stroke was two and a half times more likely in patients with the lowest vitamin C levels, while another study concluded that low (below 50 mmol/l) vitamin C levels increase the prevalence of cardiovascular issues by 77%. (8) 

An especially compelling study found a 30% reduction of the risk of cardiovascular diseases as a result of taking vitamin C food supplements, while high consumption of vegetables and fruits only resulted in a 15% reduction. (1) 

Could it play a role in cancer treatment? 

The anti-cancer qualities of vitamin C have been extensively researched. The majority of observational studies found that higher intakes of vitamin C reduced the risk of several types of cancer by approximately 50%. (9) 

In Linus Pauling’s study, published in the 1970s, a large dose supplement (10 grams) of vitamin C significantly increased the survival rate of patients compared to those who only received traditional therapy. (10) A Japanese study observed similar results: large doses of vitamin C likewise increased survival rates.(11) 

Although later studies have not found similar results, the data of a meta-analysis indicate that large doses of intravenous vitamin C supplementation can complement traditional therapies, since it improves patients’ quality of life, alleviates their symptoms, and in addition, there is mention of several cases where a symptom-free state could be achieved with the help of intravenous vitamin C supplementation in large doses. (12) 

While the everyday use of average doses of vitamin C has more of a preventative effect, a larger dose can be effective due to entirely different mechanisms. In the latter case, vitamin C can increase oxidation in cancerous cells, which blocks the function of an enzyme that has a key role in their metabolism; as a result, the cancerous cells die. (13) Hopefully, further studies of a similar nature will be done in the future that shed more light on the role of vitamin C in cancer treatment. 

Vitamin C accelerates regeneration 

Vitamin C is an indispensable component for injury recovery. It is a well known fact that increased collagen production is necessary to the proper regeneration of injuries; this is impossible without vitamin C. (14) The injured body needs more vitamin C, as increased collagen production and inflammatory processes use up more vitamin C than normal. 

Vitamin C supplementation sped up the recovery process of broken bones, increased collagen production and reduced oxidative stress in multiple studies, with no side effects. (15) 

Bear in mind 

It’s advisable to strive for maintaining a steady supply of vitamin C, as it is necessary for countless biological functions. Several factors influence how much vitamin C the body needs, so supplementation must be done in accordance with one's own needs. Since vitamin C is particularly cheap and safe, its optimal levels can be guaranteed through supplementation regardless of one’s diet.