"Cross-sectional and longitudinal population-based studies published within the past 2 decades suggest no differences in bone mineral density (BMD), for both trabecular and cortical bone, between omnivores and lactoovovegetarians (40). More recent studies with postmenopausal Asian women showed spine or hip BMD was significantly lower in long-term vegans (41, 42). Those Asian women, who were vegetarian for religious reasons, had low intakes of protein and calcium. An inadequate protein and low calcium intake has been shown to be associated with bone loss and fractures at the hip and spine in the elderly (43, 44). Adequate calcium intake may be a problem for vegans. Although lactoovovegetarians generally consume adequate amounts of calcium, vegans typically fall short of the recommended daily intake for calcium (8, 45, 46). Results from the EPIC-Oxford study provide good evidence that the risk of bone fractures for vegetarians was similar to that of omnivores (46). The higher risk of bone fracture seen in vegans appears to be a consequence of a lower mean calcium intake. No difference was observed between the fracture rates of the vegans who consumed >525 mg calcium/d and the omnivore fracture rates (46)." From the article
