National Institutes of Health
Office of Dietary Supplements: Vitamin a and Carotenoids
This fact sheet on vitamin A answers questions such as "What foods provide vitamin A?" and "When can vitamin A deficiency occur?" Learn how vitamin A, though a necessary for health, can hurt the human body when overconsumed. Tables...
US National Library of Medicine
Medline Plus: Vitamin A
This encyclopedia article is organized into the following sections: Illustrations, Alternative Names, Definition, Function, Food Sources, Side Effects, and Recommendations. Click the thumbnails in Illustrations to pull up two charts, one...