Little is known about the vitamin D status of patients with severe psychiatric disorders, a potential contributing factor to elevated rates of morbidity and mortality. This descriptive study assessed serum 25-hydroxyvitamin D [25(OH)D] levels in hospital patients with schizophrenia-spectrum disorder, compared to a non-patient control group.Assessment of serum 25(OH)D levels in 20 acute care (≤60 days), 20 long-stay (≥6 months) adult public psychiatric hospital inpatients with schizophrenia-spectrum disorders, compared to 20 normal controls.High rates of hypovitaminosis D were found in all three groups with no significant differences in levels between groups: mean±SD 25(OH)D levels acute care patients 19.1±9.8ng/ml, long-stay patients 20.0±8.9ng/ml, normal controls 22.7±13.0ng/ml. Over half of all subjects (32 out of 60) had deficient levels (<20ng/ml). Younger subjects (<50 years old) had significantly lower mean 25(OH)D levels than older subjects (18.5±8.6ng/ml and 24.8±13.1ng/ml respectively, p=0.03).: Our data provide additional evidence for high prevalence rates of vitamin D deficiency in the general population, including patients with schizophrenia-spectrum disorders regardless of acute care or long-stay inpatient status.