Facts About Vitamin A
What is vitamin A?
“Vitamin A” is the blanket term for retinoids, biologically active compounds that occur naturally in both plant and animal tissues.
The vitamin A that comes from animal sources is fat-soluble, and in the form of retinoic acid, retinal and retinol.
The vitamin A in fruits and vegetables is in the form of “provitamin A” -vitamin A precursors also known as carotenoids, which must be converted by the human body into usable retinoids. They are water-soluble and do not accumulate in the body, so toxicity is rare.
Why is vitamin A necessary?
- Vitamin A plays a vital role in bone growth,reproduction and immune system health
- It also helps the skin and mucous membranes repel bacteria and viruses more effectively.
- It is essential to healthy vision, and may slow declining retinal function in people with retinitis pigmentosa
What are the signs of a deficiency?
Vitamin A deficiency is common in developing countries.
- One of the earliest signs of a deficiency is night blindness. Permanent blindness can result if the deficiency is left unchecked.
- Vitamin A deficiency also allows opportunistic infectious diseases such as measles and pneumonia to become deadly.
How much need?
- About 5000IU(adult)
- About 6000IU(pregnant women)
- About 8000IU(breast feeding mother)
- About 2000-4500Iu(1-12years old children)
How do you get enough vitamin A from foods?
- The richest animal source of retinols is beef liver.
- The best natural sources of carotenoids are fruits and vegetables, including
- butternut squash
- pumpkins and
- pumpkins and
- sweet potatoes.
Are there risks associated with too much vitamin A?
Excessive, chronic intake of some forms of vitamin A can be toxic. Avoid taking supplemental vitamin A as retinol or retinoic acid, and instead use plant-derived vitamin A precursors such as beta-carotene (in addition to other mixed carotenoids). Also avoid concentrated animal sources such as cod liver oil (although some forms of cod liver oil are vitamin A reduced and are safe – check the label). Warning symptoms of overdose include hair loss, confusion, liver damage and bone loss.