Fatigue is one of the most prevalent symptoms of vitamin D deficiency. Chronic daytime drowsiness can have a negative impact on an individual's quality of life, and low blood levels can cause myopathy and skeletal muscle fatigue. Cancer patients, in particular, have shown an increase in exhaustion. Another symptom of vitamin D deficiency is sleep apnea, sudden jerking body movements while sleeping, and intermittently waking up at night. A study on women found those with low levels of vitamin D complained of exhaustion more than those with normal levels. Lower vitamin D is also linked with lower hemoglobin and anemia. Those who are anemic are prone to experience chronic drowsiness.
Keep going for more on what to watch for in vitamin D deficiencies.