Vitamin A

Vitamin A is a vitamin, a group of organic chemicals including retinal and several carotenoids. The human body does not make these chemicals, and must take them from food. Egg yolks and liver are both rich in vitamin A. Many parts of the body need vitamin A. For example, vitamin A helps sight and is good for the immune system. It is also important for a growing embryo.

β-carotene, a provitamin found in foods like carrots can be converted to vitamin A.^[1] The efficiency of the conversion depends on genetics and fat consumption.

Too little vitamin A is dangerous to health.^[2] People who do not get enough of the vitamin may lose the ability to see in poor light and suffer from a weakened immune system. They may also have problems with memory, because vitamin A is important for the brain. People with malnutrition often have too little vitamin A. This is common in poor countries.

1. ↑ Chichili, Gurunadh Reddy; Nohr, Donatus; Schäffer, Michael; Lintig, Johannes von; Biesalski, Hans K. (2005-10-01). "β-Carotene Conversion into Vitamin A in Human Retinal Pigment Epithelial Cells". Investigative Ophthalmology & Visual Science. 46 (10): 3562–3569. doi:10.1167/iovs.05-0089. ISSN 1552-5783. PMID 16186334.
2. ↑ "Dietary Supplement Fact Sheet: Vitamin A and Carotenoids". Ods.od.nih.gov. 2006-04-23. Archived from the original on 2010-08-08. Retrieved 2010-08-20.