Dietary Retinol—A Double-edged Sword
- Margo A. Denke, MD
- Author Affiliation: Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas.
Since this article does not have an abstract, we have provided the first 150 words of the full text.
In this issue of THE JOURNAL, Feskanich and colleagues1 report that women enrolled in the Nurses' Health Study (NHS) who had the highest intake of vitamin A and, specifically, retinol had higher rates of nontraumatic hip fracture than women with the lowest intake. This association raises important questions on the safety of long-term ingestion of dietary retinol. But should these observations alter recommendations for retinol or provitamin A intake from foods, fortified foods, and supplements? To answer, the sources and functions of dietary vitamin A must be considered.
The term vitamin A refers to a family of essential, fat-soluble dietary compounds required for vision, growth, reproduction, cell proliferation, cell differentiation, and the integrity of the immune system.2 The most potent vitamin A compound, all-trans retinol, is capable of reversing signs and symptoms of vitamin A deficiency. Although all-trans retinol has been retained as the standard against …
