In 1746, James Lind, a British physician, conducted the first nutrition experiment on human beings in an effort to find a cure for scurvy. However, it was not until nearly 200 years later that ascorbic acid, or vitamin C, was discovered. Vitamin C participates in many reactions by donating electrons as hydrogen atoms. In a reducing reaction, the electron in the hydrogen atom donated by vitamin C combines with other participating molecules, making vitamin C a reducing agent, essential to the activity of many enzymes. By neutralizing free radicals, vitamin C may reduce the risk of heart disease, certain forms of cancer, and cataracts.
Vitamin C is needed to form and maintain collagen, a fibrous protein that gives strength to connective tissues in skin, cartilage, bones, teeth, and joints. Collagen is also needed for the healing of wounds. When added to meals, vitamin C increases intestinal absorption of iron from plant-based foods. High concentration of vitamin C in white blood cells enables the immune system to function properly by providing protection against oxidative damage from free radicals generated during their action against bacterial, viral, or fungal infections. Vitamin C also recycles oxidized vitamin E for reuse in cells, and it helps folic acid convert to its active form, (THF). Vitamin C helps synthesize carnitine, adrenaline, epinephrine, the neurotransmitter serotonin, the thyroid hormone thyroxine, bile acids, and steroid hormones.
A deficiency of vitamin C causes widespread connective tissue changes throughout the body. Deficiencies may occur in people who eat few fruits and vegetables, follow restrictive diets, or abuse alcohol and drugs. Smokers also have lower vitamin-C status. Supplementation may be prescribed by physicians to speed the healing of bedsores, skin ulcers, fractures, burns, and after surgery. Research has shown that doses up to 1 gram per day may have small effects on duration and severity of the common cold, but not on the prevention of its occurrence.
Some conditions have been shown to increase vitamin C requirements. They are:
1. environmental stress,
2. use of certain drugs (such as oral contraceptives),
3. tissue healing of wounds,
4. growth (children and pregnant women),
5. fever and infection, and
6. smoking.
Vitamin C also serves as an antioxidant. It works with vitamin E as a free-radical scavenger. Studies suggest that vitamin C may reduce the risk of certain cancers, heart disease and cataracts. Research continues to document the degree of these effects.
Vitamin C can be lost from foods because of its water solubility, and sensitivity to heat, air or oxygen. The addition of alkalis, such as bicarbonate of soda, and the use of copper cookware can also destroy it.
Common food sources | Citrus fruits, strawberries, broccoli, green vegetables and fruit. |
Major functions | Essential for the maintenance of bones, teeth and gums, ligaments and blood vessels. It is also necessary for ensuring a normal immune response to infection. |
Recommended daily intake | Infants: 40 - 50 mg Children: 15 - 25 mg Adolescents: 45 - 75 mg Men: 90 mg Women: 75 mg Pregnant Women: 80 - 85 mg Lactating Women: 115 -120 mg Smokers: + 35 mg. |
Deficiency symptoms | Scurvy: fatigue, poor wound healing, pinpoint hemorrhages around hair follicles on back of arms & legs, bleeding gums & joints. |
Overconsumption symptoms | Megadoses over 2 g/day causes nausea, abdominal cramps, and diarrhea. |
Stability in foods | Vitamin C can be lost from foods because of its water solubility, and sensitivity to heat, air or oxygen. The addition of alkalis, such as bicarbonate of soda, and the use of copper cookware can also destroy it. |
Vitamin C Food Chart
Cereals, Cakes, Biscuits, Desserts | Content(milligram per 100 grams) |
---|
Cheesecake | 2 |
Jam tart | 4 |
Pizza,cheese & tomato | 3 |
Triffle | 1 |
Fish and Seafoods | Content(milligram per 100grams) |
---|
Roe, Cod, fried | 26 |
Meat and Meat Products | Content(milligram per 100 grams) |
---|
Chicken livers, fried | 13 |
Lamb, brain, boiled | 17 |
Lamb, heart, roast | 11 |
Lamb, kidney, fried | 9 |
Lamb, Liver, fried | 12 |
Milk and Milk Products | Content(milligram per 100 grams) |
---|
Milk, cow's,cond,skim,sweet | 2 |
Dried,skimmed | 6 |
Dried,whole | 6 |
Goat's | 2 |
Human | 4 |
Yoghurt | 1 |
Cream | 1 |
Milkshake | 1 |
Vegetables | Content(milligram per 100 grams) |
---|
Mushrooms, raw | 3 |
Broccoli, boiled | 34 |
Cauliflower, raw | 60 |
Cauliflower, boiled | 20 |
Cabbage, raw | 60 |
Cabbage, bolied | 15 |
Carrots, raw | 6 |
Carrots, boiled | 4 |
Beans, French, boiled | 5 |
Asparagus, boiled | 10 |
Bamboo shoots | 4 |
Celery, raw | 7 |
Celery, boiled | 5 |
Cucumber, slices | 8 |
Beet root, slices, boiled | 5 |
Egg plant | 3 |
Lettuce, rawleaves | 15 |
Onions, Raw | 10 |
Onions, boiled | 6 |
Peas, canned | 8 |
Potato baked/boiled | 8/9 |
Parsley, spring | 150 |
Potato chips | 10 |
Pumpkin | 5 |
Radish | 25 |
Spinach leaves | 25 |
Sweet corn | 9 |
Parsnip | 10 |
Fruits | Content(milligram per 100 grams) |
---|
Apple | 6 |
Banana | 10 |
Apricot, dried | 6 |
Avocado pear | 15 |
Blackberries | 20 |
Cherries | 4 |
Currants, black | 200 |
Figs | 2 |
Grapes | 3 |
Guava | 180 |
Grapefruit | 19 |
Lemon slices | 80 |
Juice | 50 |
Lychees | 8 |
Mango | 30 |
Orange | 38 |
Orange juice | 50 |
Papaya | 65 |
Pear | 2 |
Pineapple | 25 |
Plums | 3 |
Peach | 7 |
Sugars, jams and spread | Content(milligram per 100 grams) |
---|
Almond | 0.1 |
Jam fruit | 10 |
Marmalde | 10 |
Sauces and condiments | Content(milligram per 100 grams) |
---|
Chilli sauce | 30 |
tr> Tomato sauce | 10 |
Chutney, tomato | 8 |
Barbecue sauce | 5 |
Tartaric sauce | 3 |
Beverages | Content(milligram per 100 grams) |
---|
Ovaltin | 48 |
Cider,sweet,non-alcoholic | 2 |