Vitamin A

“The Eye Vitamin” – Vitamin A is essential for keen eyesight, especially night vision.

Vitamin A is a fat-soluble vitamin. Comes in 2 forms: Retinol and Beta-carotene:

• Retinol is pre-formed (ready made) vitamin A. Found in animal foods. Toxic in high doses.
• Beta-carotene (pro-vitamin A) is found in many fruits and vegetables. No significant toxicity has been observed. When we consume beta-carotene, and enzyme in our stomach converts it into vitamin A.

Vitamin A plays an important role in several key processes in the body, but the most important role is in vision.

Vitamin A is a constituent of retinal. When combined with a protein called opsin in the eye retina, forms Rhodopsin. Rhodopsin is very important for night vision. A deficiency in Vitamin A can cause night blindness.

Vitamin A is also important in maintaining a healthy cornea (the surface of the eye). Vitamin A deficiency leads to xerophthalmia (a drying of the eye surface). This can lead to cloudiness of the eye, followed by ulcer formation.

Another important benefit of Vitamin A is in the prevention of premature aging of the skin. Sometimes known as the “skin vitamin”. In Europe, many skin creams are made from beta-carotene and vitamin E.

Functions/Benefits
• Anti-oxidant properties.
• Anti-cancer.
• Fights skins disorders and prevents (and reverses) ageing of the skin.
• Treats acne.
• Improves vision and prevents night blindness.
• Boosts immunity.
• Promotes healthy strong bones, hair, teeth & gums.
• Speeds wound healing.

Deficiency symptoms
• Night blindness.
• Persistent headaches.
• Acne.
• Reduced resistance to infections (particularly respiratory related).
• Mouth ulcers.
• Dry scaly skin, skin problems.
• Dry/brittle hair, dandruff.
• Kidney stones.
• Fatigue.
• Loss of energy and vigour.

Food sources
• Retinol: Fish liver oil, meats and animal products. Eggs. Butter. Cheese. Liver.

• Beta-carotene: Bright coloured fruits and vegetables – Carrots (one average-sized carrot provides 5,000 IUs of beta-carotene), sweet potatoes, broccoli, spinach, turnip greens, kale, cantaloupe, winter squash, mustard greens, beet greens, papayas, apricots, water-melons, tomatoes and lettuce.

The bio-availability of Vitamin A and other fat-soluble vitamins is improved with the consumption of fat or oil as well as protein in the same meal. Together with vitamin C & vitamin E in the same meal also helps to ‘protect’ vitamin A and enhance its bio-availability. However, vitamin E in high doses (more than 600 IUs) has been shown to interfere with beta-carotene absorption.

Nutrient Destroyers
Caffeine. Alcohol. Excessive iron. Vitamin D deficiency.

More info >> Nutrient Destroyers

U.S. RDA: 3,000 IUs.
EU RDA: 800 mcg (2,700 IU).
Retinol – DO NOT exceed 15,000 IU
Beta carotene – Up to 25,000 IU is ok.

When to take
Vitamin A (including vitamin D and vitamin E) are fat soluble vitamins. Best taken regularly with food, because they require some oil to or fat to improve their bio-availability, thus improving their absorption and utilization.

There is a general belief that the recommended daily allowances (RDA) is inadequate, and people with special needs (especially following illness) should have more (up to a max of 20,000 IUs for Beta-carotene. Some quarters also recommend up to 15,000 IUs for Retinol, but I strongly recommend against taking any more than the RDA of 3,000 IUs for pre-formed vitamin A (Retinol). Taking Beta-carotene is more advisable, as it is non-toxic. Our bodies will then convert beta-carotene into retinol when needed.

Contraindications
An assistant professor of medicine at Harvard University Medical School, Dr. Diane Feskanich, also explained that high levels of vitamin A (in the form of retinol) may cause bones to breakdown faster than they can rebuild.

Vitamin A as retinol should be consumed as little as possible. It is always better to take beta-carotene.

Toxicity
Toxic levels can cause hair loss, bone ache, nausea, persistent headaches, vomiting, diarrhoea, skin problems, blurred vision, skin lesions/rashes, irregular periods, liver enlargement, and birth defect in babies of women who take vitamin A while pregnant.

Vitamin A as retinol is toxic and should be avoided by pregnant women.
Beta carotene is not toxic and is considered to be safe for adults and children.

Trivia
Our liver is able to store vitamin A. Up to a year's supply can be stored in the liver..