Vitamin C or ascorbic acid was first isolated in 1923 by a Hungarian biochemist and Nobel laureate Szent-Gyorgyi and synthesized by Howarth and Hirst. It is one of the very essential nutrients and thus required for many biochemical and physiological functions of the body.
The human body cannot synthesize Vitamin C so it is required to take daily through the diet or supplement.
Sources of Vitamin C
Vitamin C is found in :
- Citrus fruits – Kiwi, Guava, Lemon, orange, grapefruits.
- Green Peppers
- Indian graspberry and other leafy vegetables
As animal sources are low in Vitamin C content therefore plant sources become highly important.
Vitamin C Bioavailability
Vitamin C is absorbed by the small intestine in our body. Generally from the circulatory system, ascorbic acid is reabsorbed through the renal tube in the kidney. Together, with renal excretion and intestinal absorption controls the serum level of vitamin C and thus bioavailability.
Low bioavailability is seen in the cases like stress, alcohol intake, smoking, fever, viral illnesses, usage of antibiotics, pain killers, exposure to petroleum products or carbon monoxide, heavy and metals toxicity.
Biochemical Functions of Vitamin C
Vitamin C helps in the synthesis of collagen, carnitine, neurotransmitter.
Collagen is the main structural protein that provides support to bones, tendons, skin, cartilage, blood vessels, heart valves, intervertebral discs, cornea, and eye lens.
Therefore it is very crucial to maintain Vitamin C which represents about one-third of the total body proteins.
Carnitine is a chemical that helps our body to generate energy from fatty acids.
It is also involved in the synthesis of several neurotransmitters. These chemicals are important for signaling in the nervous system.
Vitamin C helps in cell growth.
Vitamin C catalyzes the conversion of the neurotransmitter dopamine to norepinephrine and hence essential for the synthesis of catecholamines. Further Vitamin C is vital for maximal activity of hormones oxytocin, vasopressin, cholecystokinin, and alpha-melanotropin. It is also involved in the transformation of cholesterol to bile acids.
Vitamin C and Common Cold
The most widely known health benefits of Vitamin C is in the prevention and relief of common cold.
Attenuation of immunity in the common cold is well known. Ascorbic Acid stimulates the immune system by enhancing T-cell proliferation in response to infection. It helps in neutralizing pathogens and synthesize immunoglobulins to control inflammatory reactions.
Vitamin C and Tissue Healing
Vit C helps in healing wounds and repairing bones as it stimulates collagen synthesis. Adequate supplies of AA are necessary for normal healing process especially for post-operative patients because there is rapid utilization of ascorbic acid for the synthesis of collagen at the site of wound/ burns during postoperative period hence, administration of 500 mg to 1.0 g/day of AA is recommended to accelerate the healing process. In the cases of combined injury situation ascorbic acid pretreatment was beneﬁcial in the healing of irradiated wounds and suggested a vitamin C related therapeutic strategy to accelerate wound repair.
Vitamin C And Iron
Consuming food rich in Vitamin C can increase iron consumption. Iron is essential for the transfer of oxygen all over our bodies. Vitamin C protects against anemia due to iron deﬁciency.
Vitamin C And Infertility
Vitamin C has been used in the management of male infertility particularly in the presence of nonspeciﬁc seminal infections. Ascorbic acid as the principal antioxidant in seminal plasma of fertile men contributes up to 65 % of its total chain-breaking antioxidant capacity. Vitamin C supplementation in men may improve sperm quality.
Vitamin C and Atherosclerosis
Inadequate intake of Vitamin C may lead to problems of Atherosclerosis. Vitamin C can lower the cholesterol level by the administration of ascorbic acid in hypercholesterolemic patients. vitamin C helps in bile acid synthesis. Ascorbic Acid lowers blood cholesterol, triglycerides, lipid peroxidation, and increases HDL cholesterol. According to the study report, vitamin C leads to enhanced accumulation of cholesterol in thoracic aorta along with pathomorphological changes in blood vessels. Vitamin C administration causes a signiﬁcant reduction in LDL and an increase in HDL and thereby protects against Coronary artery disease. High intake of ascorbic acid was associated with a reduced risk of death from coronary heart disease in women than in men. Vitamin C protects against different types of oxidative stress including metal-induced oxidative stress.
Vitamin C and Cancer
Vitamin C may also help in preventing cancer by reducing oxidative stress. Free radicals are produced in our bodies because of the metabolic process but these free radicals damage the cells and cause cell death. Vitamin C acts as an antioxidant protecting the cell from free radical damage.
Vitamin C and Diabetes
Vitamin C has been associated with a decreased risk of developing diabetes mellitus (DM). In diabetic retinopathy, Vitamin C has a significant role.
Vitamin C and Immunity
Vitamin C appears to play a prominent role in boosting the human immune system. It plays a role in cell-mediated and humoral mediated immunity. Vitamin C inhibits the excessive activation of the immune system to prevent tissue damage. It also supports antibacterial activity, stimulates natural killer (NK) cells.
Vitamin C and Neurodegenerative Disorders
In different studies, it has been reported that Vitamin C is helpful in the treatment of schizophrenia.