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Thursday, October 14
 



Vitamin C
By Sharon Howard, R.D., M.S., C.D.E. FADA

Vitamin C is a popular vitamin and widely used supplement. Also named ascorbic acid, vitamin C is currently being studied for its anti-oxidant effects that may prevent certain diseases.

Deficiencies of vitamin C are rare in the United States today because foods rich in vitamin C are widely available. A severe deficiency can lead to scurvy, a disease that causes loose teeth, excessive bleeding and swollen gums. Wound healing can be reduced. The current Recommended Dietary Allowances are 60 mg a day, but researchers are suggesting an increase to 200 mg a day.

What Does Vitamin C Do?

  • Helps form the protein collagen. Collagen is the connective tissue that holds together muscles, bones, teeth, skin, cartilage and scar tissue.
  • Helps keep capillary walls and blood vessels firm, protecting you from bruising.
  • Iron from plant sources is more readily absorbed when vitamin C is present.
  • Keeps gums healthy.
  • Helps wounds heal quickly.
  • Improves immune system health.
  • Involved in the synthesis of neurotransmitters in the brain..
  • It is an important antioxidant in prevention of heart disease, cancer and cataracts. Vitamin C attacks free radicals in body fluids, not fat tissue, since it is a water-soluble vitamin.
  • May interfere with the oxidation of LDL cholesterol and reduce atherosclerosis.
  • May reduce the severity and duration of a cold. Contrary to popular knowledge of Linus Pauling's megadosing strategies, researchers in 12 well-designed studies were unable to prove and preventive effect of vitamin C on the common cold.

Vitamin C in Our Food

The current RDA is 60 mg and can easily be obtained through diet. Rich sources are citrus fruits, broccoli, cantaloupe, Brussels sprouts and strawberries. Many drinks are now fortified with vitamin C. Vitamin C is most exclusively found in plants with a small amount found in milk. Vitamin C is delicate, and the content of the vitamin in a food can be enhanced with the following tips:

  • Store food in a cool, moist place.
  • Use as soon as possible.
  • Vegetables lose vitamin C during long storage, but not the root vegetables.
  • Harvest at the peak of maturity.
  • Limit exposure to air and sunlight.
  • Avoid soaking the food in water for long periods.
  • Cook food in minimal amounts of water.
  • Microwave cooking preserves the vitamin C because water is not added.
  • Cook food in largest pieces possible.
  • Heat reduces some of the content of vitamin C in food.
  • Freeze-drying of fruit cues minimal loss of Vitamin C.
  • Frozen and canned foods, picked at the prime and optimally processed, may have more vitamin C than fresh produce that has been stored for a long time with poor temperature and humidity conditions.

Vitamin C Content of Selected Foods
FoodMg Vitamin C
Papaya (1)187
Cantaloupe (1/2) 113
Fresh orange juice (3/4 cup) 93
Orange (1) 70
Grapefruit juice (3/4 cup) 71
Sweet red pepper (1/2 cup) 95
Green pepper (1/2 cup) 66
Broccoli, cooked (1/2 cup) 58
Brussels sprouts, cooked (1/2 cup) 48
Grapefruit (1/2) 47

Watermelon (1-inch slice)

46

Strawberries (1/2 cup)

42
Cauliflower, cooked (1/2 cup) 27
Cabbage, raw (1 cup) 22
Baked potato (1) 26

Fortified foods

100 to 200

Supplementation

Many people believe in the benefits of supplementation of vitamin C, sometimes as high as 3000 mg a day. Large amounts of vitamin C can cause nausea, abdominal cramps, diarrhea and nose bleeds. Is it your cold or vitamin C making you feel this way?

Researchers disagree as to whether large doses of vitamin C cause kidney stones. People with hemchromatoses (iron overload) are cautioned not to take vitamin C supplements, but this recommendation is challenged in research studies.

Vitamin C supplementation is recommended for groups with special considerations because the vitamin C is depleted in fighting the free radicals. Smokers, people with poor dietary intake, oral and other surgery patients, pregnant women, children with poor diets, elderly people, and people with inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease should consider taking supplements. If 2000 mg of vitamin C is taken one hour before exercise, it can reduce lung discomfort and wheezing in people with asthma.

Dr. Losonszy at the National Institute for Aging found that older persons taking supplements of vitamin C and E have half the risk of dying a premature death. Dr. Mark Levine at the National Institute of Health has studied the saturation level of vitamin C and has determined that 200 mg a day saturates the body's tissues. Additional intake causes a rise in urinary excretion.

It appears that an optimal daily goal for vitamin C intake from diet and supplements (if diet is lacking) is between 60 and 200 mg a day. No harmful effects have been indicated for levels of 500 to 1000 mg a day. Research continues to evaluate any pro-oxidant as well as anti-oxidant effects vitamin C may have on our health.


Disclaimer:
The information, including opinions and recommendations, contained in this website is for educational purposes only. Such information is not intended to be a substitute for professional medical advice, diagnosis or treatment. No one should act upon any information provided in this website without first seeking medical advice from a qualified medical physician.






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