Vitamin A
Vitamin A represents a number of related compounds: retinol, retinal, retinoic acid, and a vitamin A precursor beta (b)-carotene. Vitamin A is important for night vision, for fighting infection (body immunity), and for regulating the genes to ensure their proper functioning.
![Vitamin A Vitamin A](https://images.medindia.net/patientinfo/950_400/vitamina.gif)
Dietary sources
Orange and yellow vegetables such as carrots, cod liver oil, fortified cereal, cantaloupe, whole milk, spinach, and eggs are examples of vitamin A rich foods.
Vitamin A Deficiency aftermath
Early vitamin A deficiency leads to impaired night vision, and advanced vitamin A deficiency can lead to corneal ulcers and scarring and blindness. In developing countries, vitamin A deficiency is an important cause of blindness among children. These children are also more likely to develop diarrhea and respiratory infections
![Vitamin A: Respiratory infections Vitamin A: Respiratory infections](https://images.medindia.net/patientinfo/950_400/calcium-vitamin-supplements-respiratory.jpg)
Why are supplements beneficial?
There is NO evidence that taking vitamin A supplements can prevent cancer or heart attacks. In the ATBC trial, subjects given beta-carotene had higher incidence of lung cancer than subjects not given beta-carotene.
Toxicity
Vitamin A can be toxic in high doses (Usually 10 times RDA). Symptoms of vitamin A toxicity include nausea, dry itchy skin, headache, and loss of appetite, bone and joint pain. High doses of vitamin A can also cause liver toxicity. Elderly people and people who drink alcohol heavily are more susceptible to vitamin A toxicity.
![Vitamin A: Joint pain Vitamin A: Joint pain](https://images.medindia.net/patientinfo/950_400/calcium-vitamin-supplements-joint-pain.jpg)
Tips for supplements
Eat a balanced diet and take one multivitamin daily. (Most multivitamins contain 5000 IU of vitamin A, generally in the form of beta-carotene). Additional vitamin A supplements are currently NOT recommended. Pregnant women should not take additional vitamin A supplements without medical supervision. Pregnant women should also avoid skin acne medications derived from natural and synthetic retinoids such as tretinoin (Retin-a), isotretinoin (Accutane), and psoriasis medications such as etretinate and acitretin.
![Vitamin A: Pregnancy Vitamin A: Pregnancy](https://images.medindia.net/patientinfo/950_400/calcium-vitamin-supplements-pragnancy.jpg)