Calcium deficiency does not usually cause morning stiffness in the fingers. Morning stiffness in the fingers is usually caused by inflammatory joint pathologies, such as rheumatoid arthritis and osteoarthritis, and is not directly related to calcium deficiency as an immune disease. Some diseases that cause morning stiffness may also be associated with calcium deficiency, so in some patients, calcium deficiency and morning stiffness may occur together, but they are not directly related.