Vitamin A is a fat-soluble vitamin.
Alternative NamesRetinol; Carotenoids
FunctionVitamin A helps form and maintain healthy teeth, skeletal and soft tissue, mucous membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye.
Vitamin A promotes good vision, especially in low light. It may also be needed for reproduction and breast-feeding.
Retinol is an active form of vitamin A. It is found in animal liver, whole milk, and some fortified foods.
Carotenoids are dark colored dyes found in plant foods that can turn into a form of vitamin A. One such carotenoid is beta-carotene. Beta-carotene is an antioxidant. Antioxidants protect cells from damage caused by unstable substances called free radicals. Free radicals are believed to contribute to certain chronic diseases and play a role in the degenerative processes seen in aging.
Food SourcesVitamin A comes from animal sources, such as eggs, meat, milk, cheese, cream, liver, kidney, cod, and halibut fish oil. However, all of these sources -- except for skim milk that has been fortified with Vitamin A -- are high in saturated fat and cholesterol.
Sources of beta-carotene are carrots, pumpkin, sweet potatoes, winter squashes, cantaloupe, pink grapefruit, apricots, broccoli, spinach, and most dark green, leafy vegetables. The more intense the color of a fruit or vegetable, the higher the beta-carotene content. These vegetable sources of beta-carotene are free of fat and cholesterol.
Side EffectsIf you don't get enough vitamin A, you are more susceptible to Infectious Diseases and vision problems.
If you get too much vitamin A, you can become sick. Large doses of vitamin A can also cause birth defects. Acute vitamin A poisoning usually occurs when an adult takes several hundred thousand IU. Symptoms of chronic vitamin A poisoning may occur in adults who regularly take more than 25,000 IU a day. Babies and children are more sensitive and can become sick after taking smaller doses of vitamin A or vitamin A-containing products such as retinol (found in skin creams).
See also: Hypervitaminosis A.
Increased amounts of beta-carotene can turn the color of skin to yellow or orange. The skin color returns to normal once the increased intake of beta-carotene is reduced.
RecommendationsThe best way to get the daily requirement of essential vitamins is to eat a balanced diet that contains a variety of foods from the food guide pyramid.
The Food and Nutrition Board at the Institute of Medicine recommends the following:
Infants
Children
Adolescents and Adults
Specific recommendations depend on age, gender, and other factors (such as pregnancy). Women who are pregnant or producing breast milk (lactating) need higher amounts. Ask your doctor what dose is best for you.
ReferencesHamrick I, Counts SH. Vitamin and mineral supplements. Wellness and Prevention. December 2008:35(4);729-747.
Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 237.
Anderson RA. Prescribing antioxidants. In: Rakel D, ed. Integrative Medicine. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 103.
Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academy Press, Washington, DC, 2001.
Vitamin A is a fat-soluble vitamin.
Alternative NamesRetinol; Retinal; Retinoic acid; Carotenoids
FunctionVitamin A helps form and maintain healthy skin, teeth, skeletal and soft tissue, mucus membranes, and skin. It is also known as retinol because it produces the pigments in the retina of the eye.
Vitamin A promotes good vision, especially in low light. It may also be needed for reproduction and breast-feeding.
Retinol is an active form of vitamin A. It is found in animal liver, whole milk, and some fortified foods.
Carotenoids are dark-colored dyes (pigments) found in plant foods that can turn into a form of vitamin A. There are more than 500 known carotenoids. One such carotenoid is beta-carotene.
Vitamin A comes from animal sources, such as eggs, meat, fortified milk, cheese, cream, liver, kidney, cod, and halibut fish oil. However, all of these sources -- except for skim milk that has been fortified with Vitamin A -- are high in saturated fat and cholesterol.
Sources of beta-carotene include:
The more intense the color of a fruit or vegetable, the higher the beta-carotene content. Vegetable sources of beta-carotene are fat- and cholesterol-free.
Side EffectsIf you don't get enough vitamin A, you are more likely to get infectious diseases and vision problems.
If you get too much vitamin A, you can become sick. Large doses of vitamin A can also cause birth defects.
Acute vitamin A poisoning usually occurs when an adult takes several hundred thousand IUs of vitamin A. Symptoms of chronic vitamin A poisoning may occur in adults who regularly take more than 25,000 IU a day. Babies and children are more sensitive to vitamin A, and can become sick after taking smaller doses of vitamin A or vitamin A-containing products such as retinol (found in skin creams).
See also: Hypervitaminosis A
Large amounts of beta-carotene will not make you sick. However, increased amounts of beta-carotene can turn the skin yellow or orange. The skin color will return to normal once you reduce your intake of beta-carotene.
RecommendationsThe best way to get the daily requirement of essential vitamins is to eat a wide variety of fruits, vegetables, fortified dairy foods, legumes (dried beans), lentils, and whole grains.
The Food and Nutrition Board of the Institute of Medicine -- Dietary Reference Intakes (DRIs) Recommended Intakes for Individuals of Vitamin A:
Infants (average intake)
The Recommended Dietary Allowance (RDA) for vitamins is how much of each vitamin most people should get each day. The RDA for vitamins may be used as goals for each person.
Children (RDA)
Adolescents and Adults (RDA)
How much of each vitamin you need depends on your age and gender. Other factors, such as pregnancy and your health, are also important. Ask your doctor what dose is best for you.
ReferencesSarubin Fragaakis A, Thomson C. The Health Professional's Guide to Popular Dietary Supplements. 3rd ed. Chicago, IL: American Dietetic Association, 2007.
Hamrick I, Counts SH. Vitamin and mineral supplements. Wellness and Prevention. December 2008:35(4);729-747.
Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 237.
Reviewed ByReview Date: 02/08/2011
Alison Evert, MS, RD, CDE, Nutritionist, University of Washington Medical Center Diabetes Care Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Vitamin A, Vitamin B12, Vitamin D, Folic Acid, Vitamin K, Vitamin E, Pyridoxine, Riboflavin
vitamin B and vitamin c
Vitamin a, Vitamin b, vitamin c.
Some examples of vitamins include Vitamin C (ascorbic acid), Vitamin D (calciferol), Vitamin B12 (cyanocobalamin), and Vitamin A (retinol). Each vitamin plays a specific role in maintaining overall health and proper body function.
it is a vitamin.
It's a vitamin.
vitamin E helps to protect vitamin A and fats in the body.
There are 8 types of Vitamin B: Vitamin B1 (thiamine) Vitamin B2 (riboflavin) Vitamin B3 (niacin) Vitamin B5 (pantothenic acid) Vitamin B6 (pyridoxine) Vitamin B7 (biotin) Vitamin B9 (folic acid) Vitamin B12 (cyanocobalamin
Vitamin A, Vitamin C, Folate, Vitamin E, Vitamin K, Thiamin, Riboflavin and Vitamin B6.
Vitamin A,Vitamin B6,Folic Acid,Riboflavin,Vitamin C,Vitamin E,Vitamin K
A, B, C, D, E, K Vitamin A (Retinol), Vitamin B1 (Thiamine), Vitamin B2 (Riboflavin), Vitamin B3 (Niacin), Vitamin B5 (Pantothenic Acid), Vitamin B6 (Pyridoxide), Vitamin B7 (Biotin), Vitamin B9 (Folic Acid), Vitamin B12 (Cobalamins), Vitamin C (Asorbic Acid), Vitamin D2 (Ergocalciferol), Vitamin D3 (Chloecalciferol), Vitamin D4 (Dihydroergocalciferol), Vitamin D5 (Dihydrotachysterol), Vitamin E (Tocopherol) Vitamin K1 (Phylloguinone), K2 (Menatetrenone), K3 (Menadione), K4 (Menadiol)
Orange's vitamins include: Vitamin A Vitamin B1 (thiamine) Vitamin B2 (riboflavin) Vitamin B3 (Niacin) Vitamin B5 (Pantothenic Acid) Vitamin B6 Vitamin C Vitamin E Folate