Origin of provitamin A
First recorded in 1950–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Any of the carotenoids that are precursors of vitamin A and exhibit qualitatively the biological activity of beta-carotene; they are present in fish-liver oils, egg yolk, milk products, green-leaf or yellow vegetables, and fruits.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.