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Vitamin A

by Mary Calvagna, MS

salad_spinach_eating_pregnancy 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 Allowance
FemalesMales
1 – 3300 mcg of RAE300 mcg of RAE
4 – 8400 mcg of RAE400 mcg of RAE
9 – 13600 mcg of RAE600 mcg of RAE
14 – 18700 mcg of RAE900 mcg of RAE
14 – 18 Pregnancy750 mcg of RAEn/a
14 – 18 Lactation1,200 mcg of RAEn/a
19+700 mcg of RAE900 mcg of RAE
19+ Pregnancy770 mcg of RAEn/a
19+ Lactation1,300 mcg of RAEn/a

Vitamin A Deficiency    TOP

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    TOP

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    TOP

FoodServing size Vitamin A content
(mcg of RAE)
Beef liver, cooked3 ounces6,582
Milk, fat-free8 ounces149
Whole egg, boiled1 large75
Sockeye 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 whole1,403
Carrots, raw½ cup459
Mango, raw1 whole112
Red bell pepper, raw½ cup117
Cantaloupe, raw½ cup135
Apricots, dried, sulfured10 halves63
Spinach, cooked½ cup573
Tomato juice, canned12 ounces42

Health Implications    TOP

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:    TOP

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
http://www.eatright.org
American Society for Nutrition
http://www.nutrition.org/

CANADIAN RESOURCES:

Dietitians of Canada
http://www.dietitians.ca/
Health Canada Food and Nutrition
http://www.hc-sc.gc.ca/fn-an/index-eng.php

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 by Brian Randall, MD
Last Updated: 2/7/2013