Many people use dietary supplements to improve their physical and mental well-being and their general health, but do not know if they really have any benefit. To our knowledge, little has been published on their use in the clinical environment, so we evaluated the evidence for their benefits in people whose work is physically and mentally challenging. Studies on nutrition and supplementation in athletes and military personnel have clearly shown that several compounds improve cognition, mental well-being, and physical performance. Based on this evidence, and with the many pressures faced by healthcare workers, as well as the need for concentration and endurance, some dietary supplements might be beneficial. Supplementation of a balanced diet with omega-3 fatty acids, vitamin B3, vitamin C and associated antioxidants, vitamin D, and protein, may improve a clinician's physical and mental health and their performance at work. Specific research is, however, needed to evaluate this more fully.