Vitamin C, or ascorbic acid is an essential micronutrient and a water-soluble vitamin well known for its function to support a healthy immune system, biosynthesis of collagen and a co-factor in the biosynthesis many important physiological functions in human biology.

In fact, Vitamin C is also potentially involved in cancer and cardiovascular diseases prevention.

The lack of vitamin C causes scurvy, a pathological condition leading to blood vessel fragility and connective tissue damage due to failure in producing collagen, and, finally, to death as result of a general collapse. 

Vitamin C accumulates in phagocytic cells, such as neutrophils, and it enhances chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing to support a healthy immune system.

In addition, it promotes the growth and spread of lymphocytes, a type of immune cell that increases your circulating antibodies, proteins that can attack foreign or harmful substances in your blood. It is shown to shorten the duration and severity of colds. 

Vitamin C may also function as a cancer cell killer due to its pro-oxidant capacity. Indeed, high-dose of vitamin C has been found to increase the average survival of advanced cancer patients and for a small group of responders, survival was increased to up to 20 times longer than that of controls. It also helps to prevent DNA mutation induced by oxidation. 

The effect of Vitamin C on cardiovascular diseases are also significant. Vitamin C enhances Nitric Oxide synthase activity and Nitric Oxide production resulting in relaxation of vascular smooth muscle cells to dilate the vessels. 

Variety of fruits and vegetables actually have Vitamin C content but because of prolonged storage or different cooking techniques, these Vitamin C content may be reduced.

Another way to ensure you get enough Vitamin C is to add it as a supplement to incorporate into your personal wellness routine.

References :

1. Carr, A. and Maggini, S., 2017. Vitamin C and Immune Function. Nutrients, 9(11), p.1211.

2. Bei, R., 2013. Effects of Vitamin C on health: a review of evidence. Frontiers in Bioscience, 18(3), p.1017.

3. E. Cameron, L. Pauling: Supplemental ascorbate in the supportive treatment of cancer: Prolongation of survival times in terminal human cancer. Proc Natl Acad Sci U S A 73, 3685-3689 

4. E. Cameron, L. Pauling: Supplemental ascorbate in the supportive treatment of cancer: reevaluation of prolongation of survival times in terminal human cancer. Proc Natl Acad Sci U S A 75, 4538-4542 

5. E. Cameron, A. Campbell: Innovation vs. quality control: an 'unpublishable' clinical trial of supplemental ascorbate in incurable cancer. Med Hypotheses 36, 185-189 

6. N. Gokce, J.F. Keaney, Jr., B. Frei, M. Holbrook, M. Olesiak, B.J. Zachariah, C. Leeuwenburgh, J.W. Heinecke, J.A. Vita: Long-term ascorbic acid administration reverses endothelial vasomotor dysfunction in patients with coronary artery disease. Circulation 99, 3234-3240