Vitamin A: Benefits, Sources,
RDA, Deficiency

When most people think about vitamin A, they think first of good eyesight. After all, carrots are a rich source of vitamin A, and everyone has heard that carrots are good for the eyes. In addition to its eyesight benefits, however, vitamin A is also important to the proper function of the immune system and to maintaining healthy skin. In addition, recent clinical trials have suggested that vitamin A may provide protection against pollutants found in the environment, and that it has strong antioxidant properties as well.

Dietary Sources of Vitamin A:

Diet is vital to getting plenty of vitamin A, and while supplements can help, the key to proper nutrition should always be a healthy and balanced diet. Rich sources of dietary vitamin A include milk, eggs and liver, as well as carrots, bananas and lemons.

Recommended Daily Intake of Vitamin A:

The recommended daily intake of vitamin A is 5000IU (or one gram).

Vitamin A Supplements:

Vitamin A is most often taken as part of a quality multivitamin, and it combines well with calcium, phosphorous and zinc, as well as B-complex vitamins, vitamin C, vitamin D and vitamin E.

Side Effects and Toxicity of Vitamin A:

Some toxic effects have been seen when vitamin A intake exceeds 15000IU, and signs of toxicity can include nausea and vomiting, hair loss, dizziness, bone pain and muscle aches. In addition, high lipid levels caused by excessive consumption of vitamin A can lead to liver and spleen damage.

Symptoms of Vitamin A Deficiency:

The most common symptoms of vitamin A deficiency include problems with the vision. Those suffering from vitamin A deficiency may experience dry eyes and problems with night vision. Severe vitamin A deficiency can even cause ulceration of the cornea, and that ulceration can lead to blindness.

Other symptoms of vitamin A deficiency can include frequent colds, respiratory infections, skin problems and scalp dryness.