The research published in the Endocrine Societys Journal of Clinical Endocrinology and Metabolism showed that individuals who follow a vegan diet show significant deficits in bone microarchitecture in comparison to omnivores. The study also revealed that resistance training not only improved bone deficits but had a stronger effect on vegans, suggesting that resistance training is an important strategy in maintaining bone health with a vegan diet.

Dr. Robert Wakolbinger-Habel, MD, Ph.D., of St. Vincent Hospital Vienna and the Medical University of Vienna, Austria, stated that they expected better bone structure in both vegans and omnivores who reported resistance training. However, they expected some differences in structure between vegans and omnivores, as previous literature reported higher fracture rates in vegans. 

In the study, when compared with the omnivore group, the vegan group showed significant deficits in 7 of 14 measures of BMI-adjusted trabecular and cortical structure. In comparison to omnivores, vegans who did not perform resistance training showed significant decreases in bone microarchitecture, including radius trabecular BMD, radius trabecular bone volume fraction, and other tibial and cortical bone microarchitecture measures. On the other hand, the findings of the study showed no significant differences in the bone microarchitecture of individuals who exclusively performed aerobic activities and those who reported no sports activities in the vegan or omnivore groups. 

(Source: https://www.medscape.com/viewarticle/979137 )