Vitamin A for Eye Health
Some of our living styles would use up Vitamin A at a faster rate. for example, many of us spend time working till late at night, or watch too much TV.
If you feel that you have difficulty seeing at night, or that driving in the dusky light of sunset is inconvenient, you may be suffering from deficiency in Vitamin A. Other early symptoms of vitamin A deficiency include burning, itching and inflamed eyes, a feel that one has sand in the eyes. The condition is called conjunctivitis.
If the vitamin A deficiency worsens, it can lead to extremely dry eyes (xerosis), followed by wrinkling, progressive cloudiness, and increasing softening of the corneas (i.e., keratomalacia) and night-blindness.
With advancing vitamin A deficiency, dry, "foamy," silver-gray deposits (Bitot spots) may appear on the delicate membranes covering the whites of the eyes. Without adequate treatment, increasing softening of the corneas may lead to corneal infection, rupture (perforation), and degenerative tissue changes, resulting in blindness. In addition, in some cases, vitamin A deficiency may have additional effects, particularly during infancy and childhood.
In some developing countries, vitamin A deficiency in the diet and associated keratomalacia are a major cause of childhood blindness. In such regions, vitamin A deficiency often occurs as part of nonselective general malnutrition in infants and young children. Although rare in developed countries, vitamin A deficiency and keratomalacia may occur secondary to conditions associated with impaired absorption, storage, or transport of vitamin A, such as celiac disease, ulcerative colitis, cystic fibrosis, liver disease, or intestinal bypass surgery and any condition that affects absorption of fat-soluble vitamins.
|The beta-carotene in leafy vegetables such as spinach can be converted into retinol in the body|
Good sources of this nutrition
Vitamin A is fat-soluble. Some good sources of this nutrition for eye health include cod liver oil, halibut liver oil, milk, eggs and butter.
|Bring some dried apricot to school or work|
Carrots, mangoes, papaya, cabbage and green leafy vegetables contain a substance called carotene, from which the body can make its own vitamin A. However, do note that carotene is extremely sensitive to oxygen in the air. Within twenty minutes of peeling, cutting vegetables, most of the vitamin A is lost. Therefore, you should try to consume the fruits and vegetable immediately after cutting or peeling them.
Our body can use Vitamin A immediately or store it in the liver for future use.
What if you are low on this nutrition?
The symptoms of deficiency will occur when you do not have sufficient vitamin A over a long period of time. Some of the symptoms are:
- dry, itchy eyes that tire easily.
- poor vision in low light and adjust slowly when going from light to dark.
- ulceration of tge cornea and eventual blindness in severe deficiency.
- Infections such as colds and sinus may be more frequent.
- dry and bumpy skin, especially on the back of the arms
- lustreless hair, dry scalp
When extra may be needed?
The World Bank's World Development Report has declared that the vitamin A supplementation discovery now represents one of the most cost effective of all known health interventions.
- For child during rapid teeth growth or for elderly with small appetites
- If you consume moderate of large amount of alcohol
- If you have heavy or painful periods, or pre-menstrual syndrome
- If you are a smoker or live in a polluted area
- If you are stressed, especially from illness
- If you have diabetes or an under-active thyroid gland
- During pregnancy and when breast feeding
Vitamin A Toxicity Warning
Vitamin A can be toxic at abnormally high dosages. While vitamin A supplementation can be beneficial, never take unusually high dosages without supervision or direction from a medical doctor. Williams Textbook of Endocrinology 10th ed (2003) says bone loss and defects are among the many symptoms that can occur with development of hypercalcemia, a condition that can result when vitamin A supplementation is 10 times higher than the recommended daily requirement of 5000 I/U.