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.
References in periodicals archive ?
Preformed vitamin A is found in animal products such as meat,fish, poultry and dairy foods
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.
Even today the average amount of preformed vitamin A in most multi-nutrient formulas is far too high in relation to vitamin D content.
The intake of preformed vitamin A from animal products is not sufficient in portions of the population in the U.
Avoid getting too much preformed vitamin A, also died retinol, which can block the effects of vitamin D.
A few companies are making supplements that replace most of the preformed vitamin A with beta carotene and contain adequate doses 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.
Preformed vitamin A is active retinol as opposed to beta-carotene that can convert to retinol in the body.