Vitamin A is primarily a large number of related compounds. Retinal, an aldehyde, and retinol, an alcohol, are some of the commonly preformed vitamin A. Some of the major vitamin A rich foods include carrots, broccoli, spinach and liver.
Retinoic acid, which is the vitamin A form that can affect gene transcription, is formed when the body converted retinal into retinol. Retinal, retinol, and retinoic acid are compounds referred to as retinoids.
Carotenoids such as beta-carotene can be formed into retinol by the body and called as provitamin A carotenoids.
Vitamin A is essential for maintaining and forming healthy skin, mucus membranes, teeth, and skeletal and soft tissue. Due to the fact that it is responsible in producing the retina’s pigments in the eye, it is also known as retinol. It aids in promoting good vision particularly in low light and it is also required during lactation and reproduction. Retinol, the active form of vitamin A, is found in whole milk, animal liver and fortified foods.
Vitamin A RDA
The Food and Nutrition Board (FNB) of the Institute of Medicine revised the Recommended Dietary Allowances (RDA) for vitamin A in 2001. The recent RDA is dependent on the amount needed to guarantee there is an adequate store of vitamin A in the body for four consecutive months to support normal immune function, reproductive function, gene expression and vision.
FEMALE: mcg/day (IU/day)
MALE: mcg/day (IU/day)
|0 to 6 months||400 (1,333 IU)||400 (1,333 IU)|
|7 to 12 month||500 (1,667 IU)||500 (1,667 IU)|
|1 to 3 years||300 (1,000 IU)||300 (1,000 IU)|
|4 to 8 years||400 (1,333 IU)||400 (1,333 IU)|
|9 to 13 years||600 (2,000 IU)||600 (2,000 IU)|
|14 to 18 years||700 (2,333 IU)||900 (3,000 IU)|
|19 years and older||700 (2,333 IU)||900 (3,000 IU)|
|Pregnancy 18 years and younger||750 (2,500 IU)||–|
|Pregnancy 19 years and older||770 (2,567 IU)||–|
|Lactating 18 years and younger||1,200 (4,000 IU)||–|
|Lactating 19 years and older||1,300 (4,333 IU)||–|
Children who have vitamin A deficiency are more likely to develop night blindness or impaired dark adaptation. Prolonged or severe vitamin deficit causes dry eye or xerophthalmia, while Bitot’s spots – changes in the corner of the eye (conjunctiva) results to having mild vitamin A deficiency.
Vitamin A Rich Foods
Consuming a variety of vitamin A rich foods are the best way to have sufficient amount, wherein there is no need to rely on supplements. Since vitamin A is a fat-soluble vitamin, too much intake can be toxic. Some of the healthy selections that contain vitamin A include carrots, apricots, spinach, turnip green, kale, mango, sweet potato, cod liver oil, fortified foods such as cereals and whole grains, squash, pumpkin, collards, eggs, Swiss chards, peas, papayas, honeydew melons, cantaloupes, and dairy products such as milk and yogurt. Further information on Vitamin A sources, and an in-depth list here.