### Patient: Doctor, I have been experiencing stiffness and tightness in my arms and back. Also, my mouth has been feeling dry lately and I have been having infrequent menstruation. What could be the problem?
### Doctor: Based on your symptoms, you might be suffering from Vitamin D deficiency. It is a common condition that causes muscle weakness, bone pain, and fatigue. We can do a blood test to confirm the diagnosis and suggest proper treatment.