Vitamin C and Eye Health
Vitamin C is important for healthy lens of the eyes. Very low levels of vitamin C in the lens would cause glucoma and cataracts.
There is some evidence that vitamin C may be effective in treating glaucoma (a dreadful condition in which the pressure of the flid inside the eye rise abnormally), and prevent cataract.
This antioxidant joins forces with vitamin E and beta-carotene to squelch free radicals and prevent oxidation of cholesterol particles.
Vitamin C is essential for the-production of collagen, which is a structural protein that holds the body together and is essential for the healing of wounds. Vitamin C is vital for a healthy skin and helps to delay the onset of wrinkles, as well as other age-related disorders such as arthritis. It boosts the immune system, alleviates allergic conditions and enhances the production of several hormones. It is probably the vitamin that is most frequently taken as a supplement.
You would need much more vitamin C when you are sick or stressed. If you can take 2000 mg of vitamin C daily, you may be able to tolerate 10,000 mg when you are sick.
Good food sources
Vitamin C is found mainly in fresh fruit and vegetables, including citrus fruits, tomatoes, melons, green leafy vegetables and papayas.
Very little vitamin C is stored in the body and, as it cannot be manufactured in humans, foods containing it should be eaten every day, preferably at every meal. It is easily lost from food in cooking. Vitamin C is easily destroyed by heat and long storage. Therefore, it is better to eat them raw and fresh.
What happen if your intake is too low?
A wide range of medical problems has been associated with insufficient vitamin C, including increased susceptibility to infections of all types, poor wound-healing and easy bruising, anaemia, asthma, heart disease and psychological problems such as anxiety and depression. Severe deficiency causes the bleeding gums, painful joints, muscle fatigue and dry scaly skin of scurvy, which is fortunately rare nowadays. However, some of these symptoms may occur if you suddenly stop taking high doses of vitamin C supplements: they should be reduced gradually to give the body time to adjust.
When extra may be needed
- During times of stress, or when you are exposed to heavy pollution
- When you have an infection, especially if you are on antibiotics
- After surgery, or if you have a wound that is slow to heal, such as a leg ulcer
- If you smoke or regularly consume moderate or large amounts of alcohol. Smoking one cigarette would destroy about 25 mg of vitamin C.
- When taking the birth-control pill, anti-histamine medication for allergies, steroids, or receiving hormone replacement therapy
(Pregnant and breast-feeding women should consult a doctor, midwife or qualified nutritional therapist bifare taking any vitamin ar mineral supplement.)
Can too much be toxic?
When taken as a supplement, vitamin C can cause diarrhoea, nausea, burning urination or skin sensitivities. Reduce the dose if any of these should occur.
Excess vitamin C is rapidly excreted in the urine, and it is unlikely that food sources alone will cause toxicity. Women who take the minipill (progesterone only) birth-control pill should not take more than 2g of vitamin C a day as this can reduce the effectiveness of the pill. You should consult your doctor about taking high dose vitamin C supplements for long periods if you, or a close relation, have had kidney stones.
Using a supplement
Some nutritional experts believe that the basic requirement for adults is at least 500mg a day, but others disagree. Supplements are best taken in two or three doses. They are available as tablets, powders, liquid or effervescent preparations. Pure ascorbic acid can cause discomfort in the stomach and 'buffered' preparations are often better tolerated. Other formulations include sodium, calcium and magnesium ascorbate, and many contain vitamin P.