Deficiency Symptoms
Bone pain, frequent bone fractures, and softening of the bones can all be symptoms of vitamin D deficiency. So can muscle aches and muscle weakness since vitamin D helps to regulate muscle composition and prevent too much fat accumulation alongside of muscle tissue. In this context, especially in older persons, frequent falls can point to deficiency of this vitamin. The key role of vitamin D in regulation of immune response means that lowered immunity can be a symptom of vitamin D deficiency, as can the presence of any autoimmune disorder. In older persons, cognitive problems (disturbances in thought processes) and depression can be symptomatic of vitamin D deficiency, and in children, stunted growth and severe asthma have also been shown to have vitamin D deficiency as potential causes.

