Vitamin A (Retinol)
HYG-5551-05
This fact sheet is one in a series containing information to help you select
foods that provide adequate daily amounts of vitamins, minerals, and dietary
fiber. The Dietary Guidelines Advisory Committee just released the Dietary
Guidelines for Americans 2005 that convey the following nine major messages
concerning these topics:
Adequate nutrients within calorie needs
Weight management
Physical activity
Food groups to encourage: fruits and vegetables, whole grains, and nonfat or
low-fat milk and milk products
Fat
Carbohydrates
Sodium and potassium
Alcoholic beverages
Food safety
What is the importance of vitamin A?
Vitamin A, a fat-soluble vitamin, plays essential roles in vision, growth,
and development; the development and maintenance of healthy skin, hair, and
mucous membranes; immune functions; and reproduction.
How much do you need?
Vitamin A is also called retinol. Measurement of the amount of vitamin A is
taken in retinol activity equivalents (RAE). Carotene, an orange pigment found
in food, is split by the body to become two active units of vitamin A. This is
also important when calculating the amount of vitamin A in the body.
The U.S. Recommended Daily Allowance (RDA) for vitamin A is 700 RAE per day
for women and 900 RAE per day for men. The U.S. RDA given is for adults and
changes for women who are pregnant or lactating; therefore, please consult your
healthcare provider for differences.
A good source of vitamin A contains substantial amounts of vitamin A and/or
carotene in relation to its calorie content and contributes at least 10% of the
U.S. RDA for vitamin A in a serving.
Do Americans get enough vitamin A?
According to recent surveys by the U.S. Department of Agriculture (USDA), the
average intake of vitamin A (and carotene) by an American adult is adequate.
How to get enough vitamin A.
Eating a variety of foods that contain vitamin A (and carotene) is the best
way to get an adequate amount. Healthy individuals who eat a balanced diet
rarely need supplements. In fact, too much vitamin A can be toxic. Select foods
that contain excellent to good sources of vitamin A each day.
Vitamin A can be lost from foods during preparation, cooking, or storage. To
prevent loss of vitamin A:
Use raw fruits and vegetables whenever possible.
Keep vegetables (except sweet potatoes and winter squash) and fruits covered
and refrigerated during storage.
Steam vegetables and braise, bake, or broil meats instead of frying. Some of
the vitamin A is lost in the fat during frying.
What about fortified foods?
Low-fat and skim milk are often fortified with vitamin A because it is lost
during processing. Margarine is fortified to make its vitamin A content the same
as butter.
Most ready-to-eat and instant prepared cereals are fortified with vitamin A.
Fortified ready-to-eat cereals usually contain at least 25% of the U.S. RDA for
vitamin A. Cereals vary, so check the label on the package for the vitamin A
content for that cereal.
What is a serving?
The amount of vitamin A in a serving depends on the weight of the serving.
For example, ½ cup of a cooked vegetable contains more vitamin A than ½ cup of
the same vegetable raw, because the cooked vegetable weighs more. Therefore, the
cooked vegetable provides vitamin A, just not enough in a ½-cup serving to be
considered a good source.
Food companies label their products according to regulations set by the Food
and Drug Administration (FDA). Terms to define a serving of food that has 20% or
more of the RDA include: “high,” “rich in,” or “excellent source of” vitamin A.
Terms to define a serving of food that contains 10% or more of the RDA include:
“good,” “contains or provides” vitamin A. Terms to define a serving of food that
contains less then 10% of the RDA include: “enriched,” “fortified,” or “added”
vitamin A.
References
Browne, M. B. 1993. Label Facts for Healthful Eating. Mazer
Corporation, Dayton, OH.
Federation of American Societies for Experimental Biology, Life Sciences
Research Office. Prepared for the Interagency Board for Nutrition Monitoring and
Related Research, 1995. Third Report on Nutrition Monitoring in the United
States: Volumes 1 and 2. U.S. Government Printing Office, Washington, DC.
Subcommittee on the 10th Edition of the RDAs, Food and Nutrition Board,
Commission on Life Sciences, National Research Council. 1987. Recommended
Dietary Allowances, 10th ed. Academy Press, Washington, DC.
U.S. Department of Agriculture, U.S. Department of Health and Human
Services. Your Health: Dietary Guidelines for Americans, 4th ed. Home
and Garden Bulletin No. 232. U.S. Government Printing Office, Washington, DC.
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