What Causes Vertigo, Nausea And Imbalance While On Treatment For Osteoporosis?

My mother aged 60, is having right shoulder osteoporosis, she has consulted orthopedician and taking medicines for that. But she is having severe vertigo, nausea, imbalance problems. This happens usually in morning time. She does not have Diabetes. Doctors have adviced to consult neurologists. What do you think the reason this disease, Can you explain the severity of this disease?