Correction of Low Vitamin D Improves Fatigue: Effect of Correction of Low Vitamin D in Fatigue Study (EViDiF Study)

Fatigue is a common presenting complaint of patients in the primary care offices. Low levels of vitamin D have been associated with fatigue in cancer patients. Normalization of vitamin D level improves their fatigue. Whether low vitamin D plays a role in fatigue in medically stable patients is not known. This prospective non-randomized therapeutic study observed the prevalence of low vitamin D in fatigue and the effect of normalization of vitamin D on fatigue. One hundred and seventy four adult patients, who presented in our primary care office with fatigue and stable chronic medical conditions,completed fatigue assessment questionnaires. Patients with low vitamin D levels received ergocalciferol therapy for 5 weeks. Scores of pre- and post-treatment fatigue assessment questionnaires were compared. Prevalence of low vitamin D was 77.2% in patients who presented with fatigue. After normalization of vitamin D levels fatigue symptom scores improved significantly (P < 0.001) in all five subscale categories of fatigue assessment questionnaires. The prevalence of low vitamin D is high in patients who present with fatigue and stable chronic medical conditions, if any. Normalization of vitamin D levels with ergocalciferol therapy significantly improves the severity of their fatigue symptoms.