Bochen, Florian Vitamin D deficiency in head and neck cancer patients - prevalence, prognostic value and impact on immune function. [electronic resource] - Oncoimmunology - e1476817 p. digital Publication Type: Journal Article; Research Support, Non-U.S. Gov't ISSN: 2162-4011 Standard No.: 10.1080/2162402X.2018.1476817 doi