Vitamin C or ascorbic acid is an essential nutrient that occurs naturally in numerous fruits and vegetables. It plays an important role in the growth and repair of body tissues. As a natural antioxidant, it protects the body from diseases and conditions related to oxidative stress such as cardiovascular diseases, arthritis and cancer.
What is Vitamin C
Vitamin C or ascorbic acid is a water-soluble nutrient. It cannot be synthesized naturally in the human body. Our daily vitamin C requirement is met primarily through dietary sources. Supplementation may be needed to prevent deficiency of this essential nutrient. Vitamin C is a powerful natural antioxidant.It plays an important role in suppressing the scavenging activities of free radicals. Moreover, it is essential for several metabolic and enzymatic reactions.
Food Sources of Vitamin C
Foods rich in vitamin C are abundant in nature. Citrus fruits such as lemon, lime, oranges and grapefruits are among the richest sources of ascorbic acid. Other vitamin C rich fruits include pineapple, mango, watermelon, cranberries, raspberries, cantaloupe, pear, guava, plum, apricot, avocado, strawberries, blueberries, kiwifruit, papaya, grapes, apple and banana.
Vitamin C is also found in a large number of common vegetables such as bell peppers, broccoli, cauliflower, kale, cabbage, Brussels Sprouts, parsley, mustard greens, turnip greens, romaine lettuce, collard greens, spinach, tomatoes, fennel, green beans, squash, basil, leeks, celery, onion, cucumber, peas, garlic, potato, sweet potato, yam and eggplant.
Functions of Vitamin C
Growth and Maintenance of Tissues
Vitamin C is needed for the growth and maintenance of all the body tissues. It is needed for the growth, repair and maintenance of collagen, a fibrous protein, which is the main structural component in bones, ligaments, tendons and blood vessels. It accelerates the wound healing process.
By strengthening the immune system, vitamin C reduces the risk of infections and boosts the ability of the immune system to fight invading microorganisms. It is essential for the health of the immune system. There is sufficient evidence to suggest the effectiveness of vitamin C in preventing cold and flu related complications such as lung infections and pneumonia. It can strengthen the immune system weakened by oxidative stress.
Vitamin C is one of the most popular natural antioxidants. Even small amounts of this nutrient can significantly enhance the antioxidant level in the human body. It protects fats, proteins, carbohydrates and the genetic materials from the reactive oxygen species or free radicals. Free radicals are produced naturally in the human body as by products of respiration and other metabolism processes.
Exposure to pollutants and toxic substances further increase the free radical levels in the body. Too much free radical in the body boosts the risk of heart diseases, stroke, arthritis, and cancer. In addition to its antioxidant property, vitamin C also aids regeneration of other antioxidant nutrients.
Absorption Of Nutrients
It is needed for aiding absorption of vitamin E, the most powerful antioxidant in nature. Vitamin C is also necessary for increasing absorption of iron from foods.
Synthesis of Norepinephrine and Carnitine
Vitamin C is needed for the synthesis of the neurotransmitter norepinephrine. Carnitine, a hydrophilic amino acid derivative, that transports fats to the mitochondria in the cells for energy production, is manufactured from amino acids methionine and lysine with the help of vitamin C.
Recent researches have documented several important functions of vitamin C. Some studies suggest that high concentration of vitamin C in the blood can reduce the risk of strokes. This essential vitamin can delay skin aging, reduce skin dryness and improve the overall appearance of the skin. In several scientific studies, researchers have observed the beneficial role of vitamin C is reducing inflammation, bringing down the risk of developing cardiovascular diseases and cancer and preventing macular degeneration.
Vitamin C promotes dilation of blood vessels. This property of vitamin C is considered beneficial for people suffering from coronary heart disease, congestive heart failure, angina pectoris, hypertension and diabetes.
Children between 1 and 3 years of age need 15 mg of vitamin C per day. The daily vitamin C requirement of children from 4 to 8 years of age and 9 to 13 years of age is 25 mg and 45 mg respectively.Adolescent boys need 75 mg of vitamin C each day; the recommended daily dose of vitamin C for adolescent girls is 65 mg.
Adult males need 90 mg of vitamin per day, and adult females require 75 mg of vitamin C daily. During pregnancy and breastfeeding, the daily vitamin C requirement in women rises to 85 mg and 120 mg per day. Smokers should consume 35 mg more vitamin C than the recommended daily allowance of vitamin C for non-smokers.
Vitamin C is a water-soluble vitamin. Therefore, it cannot be stored in the body. Excess vitamin C is eliminated through urine. To replenish the depleted vitamin C reserve, sufficient vitamin C rich foods needs to be consumed daily.
Deficiency Symptoms Of Vitamin C
The deficiency symptoms of vitamin C have been documented for several centuries. Gum bleeding or gingivitis, anemia, joint pain, inflammation of the joint, bruising, skin discoloration, hair loss and teeth loss are common symptoms of severe vitamin C deficiency. These symptoms are signs of impaired collagen synthesis that occurs when the vitamin C level in the blood is abysmally low.
Inadequate collagen synthesis weakens the blood vessels that rupture easily. However, most of the aforementioned symptoms of vitamin C can be prevented by consuming very small amounts of vitamin C daily, about 10 mg per day.Poor wound healing is another symptom of vitamin C deficiency.Fatigue occurs when diminished level of vitamin C reduces synthesis of carnitine and the neurotransmitter norepinephrine. Slow down in the metabolism rate due to poor carnitine synthesis inhibits metabolism of fats, leading to weight gain.Susceptibility to coughs, cold, flu and other respiratory infections are linked to vitamin C deficiency. Since vitamin C helps in maintaining the health of the lining of the respiratory tract, deficiency of this nutrient worsens lung related conditions and increases the risk of respiratory infections.
Vitamin C Deficiency
Severe vitamin C deficiency causes scurvy, which usually occurs in malnourished adults. Vitamin C deficiency may be responsible for anemia, dry hair, poor immunity, joint inflammation and weak tooth enamel.
Overdose Of Vitamin C
Consuming 5 or more grams of vitamin C causes diarrhea. Consuming large amounts of vitamin C boosts the uric acid level in the blood, which may increase the risk of developing uric acid stones in the kidney and gout.
How to Store Vitamin C
Vitamin C is highly vulnerable to temperature, water and air. To restore vitamin C in fruits and vegetables, the vitamin C rich foods should not be stored and refrigerated for a long time.