Does vitamin D deficiency cause finger stiffness and joint pain?

Yes, vitamin D deficiency can cause stiffness and joint pain in the fingers. This occurs because vitamin D is essential for bone mineralization, which helps provide strength and stability to joints. When there isn’t enough of this vitamin in the body, bones may become weak or brittle, leading to painful symptoms such as finger stiffness and joint pain. Furthermore, Vitamin D plays an important role in regulating calcium levels that help build strong bones. Therefore if you don't get enough of this essential nutrient from food sources or your exposure to sunlight is not sufficient (which can happen during long winters), then your body will struggle to absorb calcium which affects bone formation causing the symptoms you mentioned above.
If you think you might be suffering from a Vitamin D deficiency it is best to visit a healthcare professional who can advise on what treatment would be most suitable for your condition.