Feeling tired and fatigued can be caused by vitamin D deficiency but it's often missed, as fatigue and tiredness can be attributed to so many other conditions that are more easily identified. There have been studies done that have conclusively shown a link between fatigue and low blood levels of vitamin D. Some researchers think they are just closely related or just one of many factors. For instance, a disease caused by vitamin D deficiency, osteomalacia, has muscle weakness among its common symptoms, and this symptom can in turn, lead to extreme tiredness. Cases of chronic fatigue can sometimes affect your quality of life. Energy levels can be impacted negatively even when blood levels aren't extremely low. The consumption of vitamin D supplements may increase energy levels and resolve symptoms.Next