I have presented the case of a 77-year-old woman with SSS who was treated unsuccessfully with antiarrhythmic drugs for 5 years. During the fifth year, she developed chronic atrial fibrillation. Two years later she started to take vitamin D for unrelated reasons, and first regained regular sinus rhythm and later stopped having episodes of atrial fibrillation. The patient has been now asymptomatic for over 2 years.