Title: Plant Foods As Sources of Pro-Vitamin A: Application of a Stable Isotope Approach to Determine Vitamin a Activity Author
Submitted to: Trees for Life Journal
Publication Type: Review Article
Publication Acceptance Date: October 25, 2005
Publication Date: December 1, 2005
Citation: Grusak, M.A. 2005. Plant foods as sources of vitamin A: Application of a stable isotope approach to determine vitamin A activity. Trees for Life Journal. 1:4. Technical Abstract: Vitamin A deficiency is a serious nutritional problem throughout much of the developing world, especially among poor populations where the consumption of animal products is minimal and the diet is composed predominantly of plant-derived foods. Vitamin A is not found in plants; however, green and other colored vegetables do contain significant concentrations of pro-vitamin A carotenoids, such as beta-carotene, which can be converted to vitamin A in the human body. At present, we do not fully understand how beta-carotene is absorbed in the human gut, especially when it is consumed in a plant source, nor do we know with certainty how much of the vegetable-derived beta-carotene from most foods is converted to vitamin A (also known as that food’s vitamin A activity). Our group at the USDA/ARS Children's Nutrition Research Center at Baylor College of Medicine in Houston, Texas, along with collaborators at the USDA/ARS Human Nutrition Research Center on Aging at Tufts University in Boston, Massachusetts, have utilized a stable isotope method that allows us to directly measure beta-carotene absorption from specific vegetables or fruit, and to determine the extent to which this beta-carotene is converted to vitamin A in the body. The information gained through this methodology is important, because it helps us understand the potential of various foods to provide dietary vitamin A. It also provides a scientific basis for establishing food-based, dietary recommendations to assist people in meeting their daily vitamin A requirements.