Vitamin A

Vitamin A is a fat-soluble vitamin necessary for healthy immune functioning, good vision, particularly when light is dim or it is dark, and reproduction.

 

In addition, vitamin A is vital for forming and maintaining healthy skin, mucous membranes, teeth, skeletal and soft tissue, heart, lungs, kidneys and other organs.

 

What Foods Contain Vitamin A?

The active form of vitamin A, retinol, is found in animal-based foods including:

  • Eggs
  • Meat
  • Liver
  • Cheese and cream
  • Some fortified foods, such as milk

See more foods that contain vitamin A >

 

Vitamin A and Carotenoids

In addition, many plant foods are rich in dark pigments called carotenoids, which can turn into a form of vitamin A in the body. Though over 600 carotenoids are found in nature, only about 40 are found in the human diet. The majority of these carotenoids have antioxidant activity and therefore, they help protect the body from damage caused by free radicals.

 

What is Beta-Carotene?

geritol-vitamin-AOne of the most well recognized carotenoids is beta-carotene. Beta-carotene is found in bright yellow and orange produce including carrots, pumpkin, sweet potatoes, winter squash, cantaloupe and apricots. Fruits and vegetables with brighter, more intense hues of orange and yellow have more beta-carotene than their counterparts.

 

Health Benefits of Beta-Carotene

In addition to its important role as an antioxidant, beta-carotene is beneficial for eye health.

 

Vitamin A Deficiency

Though true vitamin A deficiency is rare in the United States, people with cystic fibrosis have an increased risk of vitamin A inadequacy. Insufficient intake of vitamin A can increase risk of developing an infectious disease and vision problems. And though vitamin A deficiency is not common in the U.S., nationwide dietary survey data (NHANES 2007-2008) show average vitamin A intake for both men and women, from both vitamin A and provitamin A carotenoids, is below the Recommended Dietary Allowance. Geritol® multivitamin contains 100% of the Daily Value of vitamin A in the form of beta-carotene.

 

Mega-dosing on Vitamin A

Too much vitamin A, or well in excess of the recommended dietary allowance (RDA), consumed on a regular basis can make adults sick.

Symptoms of vitamin A toxicity include: hair loss, greater sensitivity to sunlight, oily skin and hair, yellow skin, itching or peeling skin, bone pain or swelling, blurred vision, decreased appetite, dizziness, headache and nausea.


 

SOURCES:

Vitamin A. Medline Plus, NIH. Retrieved from: http://www.nlm.nih.gov/medlineplus/ency/article/002400.htm February 26, 2013.

Dietary Supplement Fact Sheet: Vitamin A. Office of Dietary Supplements, NIH. Retrieved from: http://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/ February 26, 2013.

Palva SA, Russell RM. Beta-carotene and other carotenoids as antioxidants. J Am Coll Nutr 1999;18(50:426-33. Retrieved from: http://www.jacn.org/content/18/5/426.long February 26, 2013.

Hypervitaminosis A. Medline Plus, NIH. Retrieved from: http://www.nlm.nih.gov/medlineplus/ency/article/000350.htm February 26, 2013.

What is Angina. National Heart, Lung, and Blood Institute, NIH. Retrieved from: http://www.nhlbi.nih.gov/health/health-topics/topics/angina/ February 26, 2013.

Chapter 17. Dietary antioxidants: a consideration of factors influencing requirements. Food and Agriculture Organization of the United Nations. Retrieved from: http://www.fao.org/docrep/004/Y2809E/y2809e0n.htm February 26, 2013.