Other names :: beta-carotene, retinol, antiophthalmic
Vitamin A famed vision-enhancing nutrient was isolated in 1930, the first fat-soluble vitamin to be discovered. The body acquires some of its vitamin A through animal fats or vegetable sources. he animal form is divided between retinol and dehydroretinol whereas the vegetable carotene can be split into four very potent groups – alpha-carotene, beta-carotene, gamma-carotene and crypto-carotene. With enough beta-carotene available in the body, the body can manufacture its own vitamin A.
Actions and benefits of vitamin A
- Vitamin A is required for night vision, and for a healthy skin.
- It boost immune system. Builds resistance to infections.
- Keeps tissue in good health.
- Vitamin A and B2 work together to help keep mucous membranes in the gastrointestinal tract healthy.
Recommended dosage of vitamin A
- 5,000 IU daily for men.
- 4,000 IU daily for women.
Deficiency symptoms of Vitamin A
- Night blindness.
- Dry hair or skin.
- Poor vision.
- Dry itchy eyes that tire easily are normally a warning of too little vitamin A.
When more may be required
More of this vitamin is required when you consume alcohol, on a low-fat diet, or a diet high in polyunsaturated fatty acids, if you smoke or live in a polluted area. It may also be indicated if you suffer from diabetes or have an under-active thyroid gland. Be careful of vitamin A in pregnancy.
Best food sources of vitamin A
Tomatoes, carrots, kale, turnip greens, spinach, broccoli, squash, yams, endive, watermelon, asparagus, apples, apricots, prunes, papaya, avocados, paprika, pumpkin and lemon grass.
How to use vitamin A
Available as:
Liquid: the best form due to its high bio availability and fast absorption. Always choose liquid as your first choice when supplementing your diet.
Tablets: available
Storage:
Heat and/or moisture may alter the vitamin. Refrigeration is recommended.
Useful References
- ClinicalTrials.gov: Vitamin A
- Facts about Vitamin A (University of Florida, Institute of Food and Agricultural Sciences) – PDF