Vitamin A from plant sources is safe," said Eunyoung Cho, the study's senior author.
Healthy food sources of vitamin A include sweet potato, cantaloupe, carrots, black-eyed peas, sweet red peppers, broccoli, spinach, dairy foods, fish and meat, especially liver, according to the U.S.
Chapter 6 is concerned with the stellate cells of the liver where vitamin A is stored.
The review gives many classical references such as the studies of Wolbach & Howe (1925) on the effects of vitamin A and the skin, and deals with the issue from a cosmetic point of view, ignoring the use of retinoids in dermatological treatment (even the use of all-trans-retinoic acid [ATRA] for acne).
After oral vitamin A treatment was successful in a patient with a radiation-induced anal ulcer, Dr.
There were 11 participants in the vitamin A group and 9 in the placebo group.
Cooking increases vitamin A
content, because beta-carotene is released when heat breaks down cell walls.
He explains, "We want to take full advantage of vitamin A's ability to boost our immune system.
Earlier work by Stephensen and others in the 1990s suggested that, although vitamin A enhanced kids' recovery from measles and other infections, it did not help, or perhaps even slowed, their recovery from bacterial pneumonia.
Three reports of vitamin A
's potentiation of liver toxicity by his team appear in the April TOXICOLOGY AND APPLIED PHARMACOLOGY.
All fat-soluble derivatives of vitamin A
are toxic in large doses; water-soluble compounds are less so and thus might be administered more liberally.
Stich and his co-workers report that weekly ingestion of 200,000 international units (IU) of vitamin A
caused leukoplakia shrinkage in 12 of the 21 study participants given the vitamin alone.