The vegetarian who could not sleep: a case report

Sleep disorders are not unusual presentations to family medicine clinicians. Similarly, patients may have diets that can render them susceptible to vitamin deficiencies. Although not a commonly considered risk factor for sleep disorders, vitamin B12 is involved in the production of melatonin, a hormone regulating the sleep-wake cycle, and supplementation of vitamin B12 has been used to treat sleep disorders. This case study described a patient who presented with a sleep disorder and who was a vegetarian. Although he lacked obvious manifestations of vitamin B12 deficiency, his serum level was almost half the lower limit of normal, and with vitamin B12 supplementation, his sleep improved