Vitamin C is an essential nutrient which has long been known to prevent and treat scurvy. It is also known to boost our immunity and was the first chemically produced Vitamin. Since the discovery of Vitamin C in the early 20th century, there has been considerable interest in its role to prevent chronic diseases such as cancer and cardiovascular diseases . A pertinent question which comes to our mind is at what dosage would Vitamin C be effective in tackling chronic diseases and if so does natural sources such as fruits and vegetables suffice or is supplementation required? It should be noted that most animals are able to synthesize Vitamin C in their own body, unfortunately humans cannot, hence Vitamin C must be consumed externally , either through the diet or supplementation. In this article we will try to answer the questions related to the dosage of Vitamin C and explore its role in preventing chronic diseases .
Role of Vitamin C as an Antioxidant
Vitamin C is one of the best antioxidants available in nature. While the food and health industry has used antioxidant as a buzzword for marketing their products it is important to understand the role antioxidants play in reducing the oxidative stress on our body. Oxygen in our body splits into atoms with unpaired electrons known as free radicals. Electrons prefer to be in pairs, hence free radicals are always looking out for electrons from other atoms. They target the DNA, proteins and cells causing damage. Free radicals have been associated with chronic diseases such as cardiovascular diseases, cancer and neurodegenerative disorders such as Alzheimer’s . Free radicals are generated within our body as well as found in our food and the water we drink , additionally they also enter our body through environmental exposure and through pesticides.
As the free radicals move in our body scavenging electrons from cells,DNA and protein antioxidants come into the picture and as shown in Figure 1 donate their electrons to the free radical thus neutralizing their harmful effect. The free radical can no longer damage healthy atoms as now they have a pair of electrons, thus becoming stable. This reduces the oxidative stress on our body.
Vitamin C and Chronic Diseases
Nobel Prize winning scientist Linus Pauling was a staunch advocate of Vitamin C for tackling chronic illnesses. Pauling believed that Vitamin C could not only cure the common cold but would also prevent heart diseases, cancer and neurodegenerative disorders. However , this recommendation by Pauling since the 1970s and despite two decades of research published by him, is still under discussion.
“By proper intake of Vitamins and other nutrients and by following a few other healthful practises from youth to middle age on, you can I believe extend your life and years of well being by twenty five even thirty five years” – Linus Pauling
The recommended daily allowance (RDA) of Vitamin C has varied across nations and population groups with women who are pregnant and lactating being recommended as high as (250-400 mg) per day while normal healthy individuals being recommended (75-100 mg/day). One argument that is used by critics of Vitamin C is the fact that Vitamin C is water soluble. Hence doses beyond the amount the body can use at any given time will be excreted away and not necessarily stored for later usage. This begs the question at what doses does Vitamin C help cancer patients? The discussion on Vitamin C and cancer prevention has been complicated by the following factors
1. Conflicting research, some studies showed megadosing Vitamin C fails to prevent breast cancer, while other studies suggested Vitamin C increased the chances of survival of those affected
2. The debate between effectiveness of orally administered Vitamin C and intravenously administered Vitamin C in terms of effectiveness in tackling cancer.
It is worth listening to the findings from New York University’s Langone Health Center’s researchers who seem to have made promising findings regarding usage of Vitamin C to kill blood cancer cells.
Research has also shown that high dosage of Vitamin C also helps improve endothelial function which is associated (poorer the endothelial function higher the risk) with increased risk of cardiovascular diseases.
Are megadoses of Vitamin C safe?
The most common question that comes to one’s mind is whether higher doses of Vitamin C are safe or not. As mentioned earlier in this article Vitamin C is a water soluble Vitamin so most of it is excreted, hence very little risk exists for higher dosage. There was a misconception among the medical community that Vitamin C increases risk of kidney stones , however population studies proved otherwise and no such risk has been established so far. Vitamin C definitely has shown great potential in preventing cancer and cardiometabolic diseases even if there is a fair amount of debate on this topic. It’s role in reducing oxidative stress is well established hence regular consumption of Vitamin C beyond the RDA may not be such a bad idea. Consult with your nutritionist or physician for advice regarding the same.