Vitamin A
En Español (Spanish Version)


Vitamin A, also called retinol, is a fat-soluble vitamin. Our bodies store fat-soluble vitamins in the liver and fatty tissues. The active form of vitamin A is found in animal tissue. Red, orange, and dark green vegetables and fruits contain precursor forms of vitamin A called carotenoids. Our bodies can convert some of these carotenoids into vitamin A.

Functions
Here are some of vitamin A's functions:

  • Plays an essential role in vision
  • Plays an important role in cell differentiation and cell division
  • Helps in the formation and maintenance of healthy skin and hair
  • Helps with proper bone growth and tooth development
  • Helps the body regulate the immune system
  • Plays an essential role in the reproduction process for both men and women
Recommended Intake:
The recommended daily dietary allowance for vitamin A is measured in micrograms (mcg) of Retinol Activity Equivalents (RAE).

Age Group (in years)Recommended Dietary AllowanceFemalesMales1 – 3300 mcg of RAE300 mcg of RAE4 – 8400 mcg of RAE400 mcg of RAE9 – 13600 mcg of RAE600 mcg of RAE14 – 18700 mcg of RAE900 mcg of RAE14 – 18 Pregnancy750 mcg of RAEn/a14 – 18 Lactation1,200 mcg of RAEn/a19+700 mcg of RAE900 mcg of RAE19+ Pregnancy770 mcg of RAEn/a19+ Lactation1,300 mcg of RAEn/a
Vitamin A Deficiency
Vitamin A deficiency is rare in the US, but it is common in developing countries. Here are some of the symptoms:

  • Night blindness
  • Decreased resistance to infections
  • Decreased growth rate
  • Diarrhea
Vitamin A Toxicity
As a fat-soluble vitamin, vitamin A is stored in the body and not excreted in the urine like most water-soluble vitamins. Therefore, it is possible for vitamin A to accumulate in the body and reach toxic levels. For adults, the tolerable upper intake level (UL) for vitamin A from dietary sources and supplements combined is 3,000 RAE daily. It is less in children. Symptoms of toxicity include the following:

  • Nausea
  • Vomiting
  • Headache
  • Blurred vision
  • Dizziness
  • Poor coordination
Too much vitamin A can cause severe birth defects. Pregnant women, and those who may become pregnant, should not take too much vitamin A from dietary sources and supplements.

Major Food Sources
FoodServing size Vitamin A content (mcg of RAE) Beef liver, cooked3 ounces6,582Milk, fat-free8 ounces149Whole egg, boiled1 large75Sockeye salmon, cooked3 ounces59
The following foods contain carotenoids, which the body converts into vitamin A.

FoodServing size Vitamin A content (mcg of RAE) Sweet potato, baked in skin 1 whole1,403Carrots, raw½ cup459Mango, raw1 whole112Red bell pepper, raw½ cup117Cantaloupe, raw½ cup135Apricots, dried, sulfured10 halves63Spinach, cooked½ cup573Tomato juice, canned12 ounces42
Health Implications
Populations at risk for vitamin A deficiency

The following populations may be at risk for vitamin A deficiency and may require a supplement:

  • People with a reduced ability to absorb dietary fat. Because vitamin A is a fat-soluble vitamin, fat is required for its absorption. Some conditions that can cause fat malabsorption include Crohn's disease, cystic fibrosis, celiac disease, pancreatic enzyme deficiency, and liver disease.
  • Children living in developing countries.
Tips for Increasing Your Vitamin A Intake:
Here are some tips to help increase your intake of vitamin A:

  • Pack cut carrots in your lunch for an afternoon snack.
  • Slice a peach, mango, or apricot on to your breakfast cereal or oatmeal.
  • Substitute a sweet potato for your baked potato.
  • Eat fruits and vegetables raw whenever possible. Vitamin A can be lost during preparation and cooking.
  • Steam vegetables, and braise, bake, or broil meat instead of frying. This will help retain some of the vitamin content.



RESOURCES:
Academy of Nutrition and Dietetics

American Society for Nutrition

CANADIAN RESOURCES:
Dietitians of Canada

Health Canada Food and Nutrition

References:
Dietary Supplement Fact Sheet: Vitamin A. Office of Dietary Supplements website. Available at: http://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/. Updated July 25, 2012. Accessed February 7, 2013.

Fairfield KM, Fletcher RH. Vitamins for chronic disease prevention in adults: scientific review. JAMA. 2002;287(23):3116-26.

Vitamin A deficiency. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what. Updated November 22, 2011. Accessed February 7, 2013.

Vitamin A overdose. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what. Updated June 22, 2010. Accessed February 7, 2013.

Last Reviewed February 2013



Health Information Library content is provided by EBSCO Publishing, fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

 

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

 

To send comments or feedback to EBSCO's Editorial Team regarding the content please e-mail healthlibrarysupport@ebscohost.com.