Beta-Carotene
Other name(s)
vitamin A, b-carotene, provitamin A
General
Beta-carotene is a type of substance called a carotenoid. Carotenoids give plants,
such as carrots, sweet potatoes, and apricots, their reddish-violet colors.
Beta-carotene is a provitamin. This means it's used by your body to make vitamin A.
Provitamin A is only found in plants. Vitamin A is also found in foods from animals.
Vitamin A from animal sources is called preformed vitamin A. This means it is in a
form your body can use directly. It's found in dairy products, fish oils, eggs, and
meat (especially liver). The vitamin A your body makes from beta-carotene doesn’t
build up in your body to toxic levels. But vitamin A from animal sources can.
Vitamin A is available in multivitamins. It's also available as a stand-alone supplement.
Vitamin A supplements can contain only beta-carotene, only preformed vitamin A, or
a combination of both types of vitamin A.
If your body doesn't use all the beta-carotene you eat to make vitamin A, the beta-carotene
that remains circulates in your body. Beta-carotene is also an antioxidant. It helps
keep cells healthy.
Main functions
Beta-carotene and vitamin A play a vital part in the reproductive process. They also
help keep skin, eyes, and the immune system healthy.
Demonstrated uses
Beta-carotene and other carotenoids help reduce free radical damage in your body.
Taking beta-carotene supplements can help you get enough vitamin A. These supplements
are considered safe.
Reasons for increased need
Poor nutrition is a leading cause of beta-carotene and vitamin A deficiency. These
problems can keep you from getting enough vitamin A:
-
Lactose intolerance
-
Celiac disease (Sprue)
-
Cystic fibrosis
Women who are pregnant or breastfeeding may need to take supplements. Be sure to talk
to your healthcare provider before doing this.
Claims
Beta-carotene may reduce the risk of some types of cancer, such as prostate cancer.
But more research is needed to know the effects of vitamin A on other types of cancer.
It may reduce the risk of heart disease and stroke. But studies seem to show that
neither beta-carotene nor vitamin A help prevent coronary heart disease.
One study found a higher risk of lung cancer in smokers and workers exposed to asbestos
when they had more beta-carotene.
Recommended intake
There are no Dietary Reference Intakes for beta-carotene. The Recommended Dietary
Allowances for vitamin A are noted below. They’re noted in micrograms (mcg) of retinol
activity equivalents (RAE). They’re also noted in International Units (IUs).
Age
(years)
|
Children
(mcg RAE)
|
Males
(mcg RAE)
|
Females
(mcg RAE)
|
Pregnancy
(mcg RAE)
|
Lactation
(mcg RAE)
|
1-3
|
300 (1,000 IU)
|
|
|
|
|
4-8
|
400 (1,321 IU)
|
|
|
|
|
9-13
|
600 (2,000 IU)
|
|
|
|
|
14-18
|
|
900 (3,000 IU)
|
700 (2,310 IU)
|
750 (2,500 IU)
|
1,200 (4,000 IU)
|
19+
|
|
900 (3,000 IU)
|
700 (2,310 IU)
|
770 (2,565 IU)
|
1,300 (4,300 IU)
|
Age (months)
|
Males and Females (mcg RAE)
|
0-6
|
400 (1,320 IU)
|
7-12
|
500 (1,650 IU)
|
Food sources
This table notes the IU of vitamin A in foods. It also notes the percentage of your
daily value of vitamin A that the food meets.
Food
|
Vitamin A (mcg RAE)
|
% DV
|
Sweet potato, baked in skin, 1 whole
|
1,403
|
156
|
Spinach, frozen, boiled, ½ cup
|
573
|
64
|
Carrots, raw, ½ cup
|
459
|
51
|
Cantaloupe, raw, ½ cup
|
135
|
15
|
Black-eyed peas (cowpeas), boiled, 1 cup
|
66
|
7
|
Apricots, dried, sulfured, 10 halves
|
63
|
7
|
Eating more fruits and vegetables can help you get more beta-carotene. Red, orange,
deep yellow, and dark green produce tends to be high in carotenoids.
Signs of deficiency
Vitamin A deficiency can cause symptoms. These include:
-
Night blindness
-
Fatigue
-
Skin issues
-
Weakened immune system
Severe vitamin A problems can lead to blindness. This is a leading cause of blindness
in some parts of the world.
Toxicity
Beta-carotene doesn’t seem to be toxic in large doses. But high doses over a long
time can lead to carotenemia. This causes your skin to become yellowish orange.
Too much beta-carotene is a problem for some people. This includes people who can't
convert beta-carotene to vitamin A. This can happen to people who have hypothyroidism.
Higher doses of vitamin A may increase the risk for fractures in both women past menopause,
and in men.
High dose supplements with preformed vitamin A are not advised during pregnancy. Too
much may cause birth defects or miscarriage.
Interactions
Orlistat, a medicine for weight loss, decreases fat absorption in the body. Because
of this, it may also reduce absorption of beta-carotene and vitamin A. Vitamin A is
a fat-soluble vitamin.
Don't use vitamin A or beta-carotene supplements if you take any of these medicines.
This is because they contain derivatives of vitamin A:
-
Isotretinoin
-
Acitretin
-
Etretinate