The relationship between 25-hydroxy vitamin D serum level and memory in patients with a first episode of schizophrenia spectrum disorder.

Abstract

The relationship between vitamin D levels and cognition in young patients with schizophrenia remains incompletely understood. We explored the association between serum 25-hydroxy vitamin D concentration and long-term memory (i.e., 30-minute delayed recall in the Rey Auditory Verbal Learning Test) in patients with first-episode schizophrenia. The body mass index was measured due to the accumulation of vitamin D in fat. Forty six male participants aged 20.9±2.3 years old with first-episode schizophrenia spectrum disorder were recruited. The median body mass index was 24.1, 25-hydroxy vitamin D was 39.3 nmol/L. The mean delayed recall was 7.6±3.4 words. Serum 25-hydroxy vitamin D concentration and memory performance were below the normative values for healthy adults. 25-hydroxy vitamin D concentrations and ten clinical variables were included as independent variables and delayed recall values were included as dependent variables in the multiple regression analysis. Regression analysis revealed a statistically significant link between 25-hydroxy vitamin D concentration, benzodiazepine use and delayed recall, but not for other clinical variables. We found a positive association between 25-hydroxy vitamin D serum concentration and delayed recall in patients with first-episode schizophrenia, supporting a need for interventional study investigating vitamin D supplementation for the cognition of patients with schizophrenia. A negative association between benzodiazepine intake and memory performance calls for attention to minimalize benzodiazepine use.