Vitamin C
Written by: Jonine Moller, M.Sc. in Sports Science
Vitamin C, or ascorbic acid, is an important antioxidant and water-soluble vitamin [1].
Vasco da Gama and Christopher Columbus will be able to tell you all about vitamin C deficiency. These sailors will motivate you to eat enough fresh produce. This is because they know what you could experience if you don’t. Scurvy - the most well-known result of a vitamin C deficiency.
Scurvy is commonly used as motivation for children to eat their fruits and vegetables. Parents will typically tell their children that their teeth will fall out or that they’ll get bleeding gums and sores if they don’t eat their fruits and vegetables. Other symptoms of vitamin C deficiency may include cork-like hair, dry skin, fatigue, and depression [2].
The early sailors did not know that a vitamin C deficiency was the actual cause of their disease. What they did realize was that a severe lack of fresh fruits and vegetables was to blame [1]. We now know that insufficient levels of vitamin C weaken our immune system. A very severe deficiency can even lead to death [3].
A vitamin C deficiency will also increase your chances for infections, in general. This is because it is involved in the production of numerous immune cells. You’ll more easily catch the flu, illnesses affecting the lungs, and other common infections [3].
Of particular interest for 2020 onwards: vitamin C has specific antiviral effects, amongst its other immune benefits. It can thus even aid in the protection against and management of the COVID-19 disease [4].
Not only is vitamin C crucial for the protection against becoming ill, but it also aids in the fight against illness. Studies have found that giving vitamin C to sick patients helped them to recover from infections [2].
Outside of the immune system, the skin needs vitamin C as well. It plays a part in stabilizing the skin’s collagen structure [3]. It is also essential for wound healing and protection against reactive oxygen species (ROS) (free radicals) that form in the body.
In short, ROS are highly reactive chemicals that damage cells. The presence of ROS is referred to as oxidative stress. Environmental toxins, as well as natural processes within the body, are sources of oxidative stress. Without vitamin C, amongst other antioxidants, the body cannot adequately control and get rid of it. As a result, various cells may be damaged, leading to illnesses such as lung diseases [3].
Furthermore, vitamin C even has anti-inflammatory mediating roles [3]. A vitamin C deficiency can worsen conditions, such as type 2 diabetes, characterized by increased inflammation levels [3]. In accordance, the risk for death due to heart disease decreases with increasing levels of vitamin C [2].
Our bodies cannot produce vitamin C. It must therefore be acquired through our diets. The recommended daily intake of vitamin C is 200 mg. It is possible to reach this amount without supplementation.
Make sure you eat at least five servings of fruits and vegetables each day. Also, make sure that at least one to two of these fruits or vegetables are high in vitamin C [5].
Good sources include green and pepper, kale, broccoli, guava, blackcurrant, kiwifruit, papaya, strawberries, and citrus fruit [5]. Vitamin C supplements can, however, aid in increasing intakes and also seem to be effective in managing infections [5, 6].
Important to note: certain conditions may increase your body’s vitamin C usage. Subsequently, your needs will increase. Such conditions are related to the causes of increased ROS production. This includes suffering from an infection of any sort or being exposed to a lot of pollution [5, 7].
Illness is subsequently one of the risk factors for becoming deficient and increases the need for higher intakes. Being very physically active also increases the body’s need for vitamin C [7].
Your genes may further place you at risk for developing a vitamin C deficiency. Having a genetic predisposition towards a deficit involves the proteins: SVCT1 and SVCT2. These proteins function as vitamin C transporters. They are responsible for the uptake and travel of this vitamin into the different target organs and cells [8].
Certain variations within the genes that code for SVCT1 and SVCT2 are associated with several diseases. These include chronic diseases such as heart disease and cancers. Altered vitamin C concentrations are ultimately the link to the increased disease risk [9].
Your daily vitamin C needs may be higher than the recommended intake, depending on your genes [9]. Your genetic makeup may thus determine how much attention you should give to your vitamin C intake. The only way to know whether you have a higher genetic need for vitamin C is to have your genes tested. Fortunately, testing your genetic susceptibility has become a much more affordable and available service!
References:
[1] Magiorkinis, E., Beloukas, A., & Diamantis, A. (2011). Scurvy: Past, present and future. European Journal of Internal Medicine, 22(2), 147–152. https://doi.org/10.1016/j.ejim.2010.10.006
[2] Schlueter, A. K., & Johnston, C. S. (2011). Vitamin C: Overview and update. Complementary Health Practice Review, 16(1), 49–57. https://doi.org/10.1177/1533210110392951
[3] Carr, A. C., & Maggini, S. (2017). Vitamin C and immune function. Nutrients, 9(11), 1–25. https://doi.org/10.3390/nu9111211
[4] Abobaker, A., Alzwi, A., & Alraied, A. H. A. (2020). Overview of the possible role of vitamin C in management of COVID-19. Pharmacological Reports, 72(6), 1517–1528. https://doi.org/10.1007/s43440-020-00176-1
[5] Rowe, S., & Carr, A. C. (2020). Global vitamin c status and prevalence of deficiency: A cause for concern? Nutrients, 12(7), 1–20. https://doi.org/10.3390/nu12072008
[6] Schloss, J., Lauche, R., Harnett, J., Hannan, N., Brown, D., Greenfield, T., & Steel, A. (2020). Efficacy and safety of vitamin C in the management of acute respiratory infection and disease: A rapid review. Advances in Integrative Medicine, 7(4), 187–191. https://doi.org/10.1016/j.aimed.2020.07.008
[7] Hemilä, H. (2017). Vitamin C and infections. Nutrients, 9(4). https://doi.org/10.3390/nu9040339
[8] Savini, I., Rossi, A., Pierro, C., Avigliano, L., & Catani, M. V. (2008). SVCT1 and SVCT2: Key proteins for vitamin C uptake. Amino Acids, 34(3), 347–355. https://doi.org/10.1007/s00726-007-0555-7
[9] Shaghaghi, M. A., Kloss, O., & Eck, P. (2016). Genetic variation in human vitamin C transporter genes in common complex diseases. Advances in Nutrition, 7(2), 287–298. https://doi.org/10.3945/an.115.009225