What is pro vitamin D3?
What is pro vitamin D3?
provitamin D3 –> 7-dehydrocholesterol. Cholesta-5,7-dien-3b-ol;a zoosterol in skin and other animal tissues that upon activation by ultraviolet light becomes antirachitic and is then referred to as cholecalciferol (vitamin D3). Synonym: provitamin D3.
What is the difference between a provitamin and vitamin?
A provitamin is a substance that may be converted within the body to a vitamin. The term previtamin is a synonym. The term “provitamin” is used when it is desirable to label a substance with little or no vitamin activity, but which can be converted to an active form by normal metabolic processes.
What is provitamin A?
“Provitamin A” is a name for β-carotene, which has only about 1/6 the biological activity of retinol (vitamin A); the body uses an enzyme to convert β-carotene to retinol. In other contexts, both β-carotene and retinol are simply considered to be different forms (vitamers) of vitamin A.
What is vitamin D3 called?
Cholecalciferol (vitamin D3) is in a class of medications called vitamin D analogs. Cholecalciferol is needed by the body for healthy bones, muscles, nerves, and to support the immune system. It works by helping the body to use more of the calcium found in foods or supplements.
Which of the following is pro vitamin?
β-Carotene (pro-vitamin A) belongs to a class of chemicals called carotenoids. It plays an important role in human physiology, and is an excellent antioxidant. There are more than 600 carotenoids in plants and bacteria. β-Carotene is the most abundant form of carotenoid, and it is also a precursor of vitamin A.
What are Antivitamins and examples?
Antivitamins are substances that inactivate or destroy vitamins or inhibit the activity of a vitamin in a metabolic reaction and increase an individual’s need for vitamins. For example, ascorbic acid oxidase, an enzyme found in fruits and vegetables, can oxidize ascorbic acid. Mushrooms contain vitamin B6 antagonists.
Is Pro Vitamin A safe in pregnancy?
During pregnancy, it’s important not to get too much preformed vitamin A, which can cause birth defects and liver toxicity in high doses. (However, it’s safe and beneficial to eat plenty of fruits and vegetables high in carotenoids.)
Where does vitamin D get activated?
Vitamin D from the diet, or from skin synthesis, is biologically inactive. It is activated by two protein enzyme hydroxylation steps, the first in the liver and the second in the kidneys.
