I have been suffering from severe joint pain for years. Doctors and specialist put this down to arthritis, but they were wrong. The cause was Omeperazole causing Vitamin B12 deficiency. It was easily corrected by taking a high dose of Vitamin B12. Within a week, pains in foot, back, hips, shoulders, and hands have nearly disappeared. Furthermore, swelling in leg has greatly reduced. Omeprazole has been dumped, and I am back on Losec 10 mg.