In the new Dietary Reference Intakes for Calcium and Vitamin D developed by the National Academy of Science, published in 2011 by the National Academies Press, the VRG website www.vrg.org is identified as the source of information on how many people in the U.S. are vegetarian (page 420). The American Dietetic Association position paper on vegetarianism co-authored by Reed Mangels is also cited. See http://books.nap.edu/openbook.php?record_id=13050&page=420