Vitamin D deficiency

Vitamin D is a fat-soluble vitamin that plays a vital role in many bodily processes. 

Vitamin D deficiency can occur due to less sun exposure, dark skin, physical blocking of sun rays, diet lacking Vitamin D, obesity, and certain conditions and medications that interfere with Vitamin D absorption.

Symptoms of Vitamin D deficiency may not occur for several months or years. Some of the common symptoms may include fatigue and tiredness, bone and muscle pain, loss of appetite, hair loss. 

This condition is usually managed with supplements. Sun exposure and eating a vitamin D-rich diet, including fatty fish and fortified dairy products also play a vital role.