preformed Vitamin A

pre·formed Vi·ta·min A

(prē'fōrmd vī'tă-min)
Retinyl esters mainly found in animal sources that are the main storage form of vitamin A.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Adults shouldn't consume more than 10,000 international units of preformed vitamin A daily, the NIH said.
The Mother Load contains a very moderate 450 mcg (1500 IU) of vitamin A (preformed vitamin A as retinyl palmitate), which is less than the recommended daily intake of 600 mcg per day," US Weekly quoted the spokesperson as saying.
* Preformed vitamin A is found in animal products such as meat,fish, poultry and dairy foods
Carrots contain beta-carotene, also known as provitamin A, not preformed vitamin A. Excessive amounts of preformed vitamin A during pregnancy are known to cause birth defects, but the beta-carotene form found in carrots does not.
One popular formula provided 25,000 IU of preformed vitamin A and only 400 IU of vitamin D.
The intake of preformed vitamin A from animal products is not sufficient in portions of the population in the U.S., Europe and Asia.
Avoid getting too much preformed vitamin A, also died retinol, which can block the effects of vitamin D.
The women, who were pregnant at enrollment and followed for a median of 71 months, were randomly assigned to receive daily one of the following: a multivitamin containing vitamins B, C, and E: a vitamin A supplement containing preformed vitamin A and [beta]-carotene; both the multivitamin and vitamin A supplement; or placebo.
The women, who were pregnant at enrollment and followed for a median of 71 months, were randomly assigned to receive daily one of the following: a multivitamin containing vitamins B, C, and E; a vitamin A supplement containing preformed vitamin A and [beta]-carotene; both the multivitamin and vitamin A supplement; or placebo.
Liver, egg yolk and fortified margarines are rich sources of preformed vitamin A (retinol), with exceptionally high levels found in liver.
"Even the nutrients recognized to present some safety concerns, such as preformed vitamin A, are safe within a wide range of intakes."