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Facts About Vitamin A and Carotenoids |
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Part 2: What
foods provide vitamin A, and how much do you need?
What foods provide vitamin A?
Whole eggs, whole milk, and liver are among the few foods that naturally contain vitamin A. Vitamin A is present in the fat portion of whole milk, so
it is not found in fat-free milk. Most fat-free milk and dried nonfat milk solids
sold in the US are fortified with vitamin A (17). There are many other fortified
foods such as breakfast cereals that also provide vitamin A. The tables of selected food sources of vitamin A suggest animal sources of vitamin A and plant sources of provitamin A carotenoids (18).
It is important for you to regularly eat foods that provide
vitamin A or beta-carotene even though your body can store vitamin A in the
liver (1). Stored vitamin A will help meet your needs when intake of provitamin
A carotenoids or vitamin A is low (19, 20).
What is the Recommended Dietary Allowance for vitamin A for adults?
The Recommended Dietary Allowance (RDA) is the average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97-98%)
healthy individuals in each life-stage and gender
group (13). The 1989 RDAs (21) for vitamin A for adults and children are:
| Age |
Children |
Men |
Women |
Pregnancy |
Lactation |
| Ages 1-3 |
400 RE or
2000 IU* |
|
|
|
|
| Ages 4-6 |
500 RE or
2500 IU |
|
|
|
|
| Ages
7-10 |
700
RE or 3,500 IU |
|
x
|
x
|
x
|
| Ages 11-18 |
|
1000 RE or
5000 IU |
800 RE or
4000 IU |
800 RE or
4000 IU |
800 RE or
4000 IU |
| Ages 19
+ |
|
1000 RE or
5000 IU |
800 RE or
4000 IU |
800 RE or
4000 IU |
800 RE or
4000 IU |
|
*Food labels list vitamin
A in International Units (IU).
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Results of the third National Health and Nutrition Examination survey (NHANES III 1988-91) (22) suggested that the dietary intake of some Americans does not meet recommended levels. The Continuing Survey of Food Intakes of Individuals (CSFII 1994) (23) suggested that diets of many Americans provide less than 75% of recommended intake levels. These surveys highlight the importance of encouraging Americans to include dietary sources of vitamin A in their daily diets.
There is no separate RDA for beta-carotene or other carotenoids. The Institute of Medicine (IOM) report suggests that consuming 3 to 6 mg of beta-carotene daily will maintain plasma B-carotene blood levels in the range associated with a lower risk of chronic diseases (13). This concentration can be achieved by a diet that provides five or more servings of fruits and vegetables per day.
Next page > Who is at risk for deficiency, and what are the symptoms? > Page 1, 2, 3, 4, 5, 6
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