Vitamin A
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Vitamin A

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 Retinol Activity Equivalents (RAE).

Age Group (in years)Recommended Dietary Allowance
FemalesMales
1 – 3300 RAE300 RAE
4 – 8400 RAE400 RAE
9 – 13600 RAE600 RAE
14 – 18700 RAE900 RAE
14 – 18 Pregnancy750 RAEn/a
14 – 18 Lactation1,200 RAEn/a
19+700 RAE900 RAE
19+ Pregnancy770 RAEn/a
19+ Lactation1,300 RAEn/a

Vitamin A Deficiency

Here are symptoms of vitamin A deficiency (rare in the US):

  • Night blindness
  • Dry skin
  • Dry hair, broken fingernails
  • Follicular keratinosis–hardened, pigmented goose bumps on the arms, legs, and hair follicles
  • Decreased resistance to infections
  • Loss of appetite
  • Decreased growth rate

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 2,800 RAE daily. Symptoms of toxicity include the following:

  • Dry, itchy skin
  • Headache
  • Fatigue
  • Hair loss
  • Loss of appetite
  • Vomiting
  • Bone and muscle pain
  • Liver damage

Vitamin A toxicity can cause severe birth defects. . Pregnant women, and those who may become pregnant, should limit their intake of vitamin A from dietary sources and supplements.

Major Food Sources

FoodServing size Vitamin A content
(RAE)
Beef liver, cooked3.5 ounces8,025
Milk, fat-free8 ounces150
Whole egg, boiled1 large70
Milk, whole8 ounces70

The following foods contain carotenoids, which the body converts into vitamin A.

FoodServing size Vitamin A content
(RAE)
Sweet potato, mashed1/2 cup1,290
Carrots, raw1 medium515
Collards, frozen, boiled½ cup490
Mango1/2 medium40
Red bell pepper, raw½ cup115
Cantaloupe½ cup150
Kale, boiled½ cup445
Apricots3 medium100
Spinach, raw1 cup140
Tomato 1 medium150
Papaya½ medium85
Orange1 medium15

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. Just poke holes in the sweet potato and cook at 350 degrees Fahrenheit for about 45 minutes to an hour (or microwave for 6 to 8 minutes).
  • 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:

American Dietetic Association
http://www.eatright.org

Nutrition.gov
http://nutrition.gov/

CANADIAN RESOURCES:

Canadian Council on Food and Nutrition
www.ccfn.ca

Dietitians of Canada
http://www.dietitians.ca/

References:

Dietary Supplement Fact Sheet: Vitamin A and Carotenoids. Office of Dietary Supplements website. Available at: http://www.ods.od.nih.gov/factsheets/vitamina.asp. Accessed January 2, 2008.

Duyff RL. The American Dietetic Association's Complete Food & Nutrition Guide. 3rd Ed. Hoboken, NJ: John Wiley & Sons, Inc; 2006.

Facts about dietary supplements. National Institutes of Health website. Available at: http://www.nih.gov.

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

Food and nutrition information center. US Department of Agriculture website. Available at: http://www.usda.gov.

The Nutrition Desk Reference. Keats Publishing; 1995.



Last reviewed December 2007 by Maria Adams, MS, MPH, RD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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