Cognition and physical functioning in patients with schizophrenia: any role for vitamin D?

ABSTRACT

Aim: The study’s objective was to evaluate the relationship between vitamin D (VD) levels and cognitive performance in patients with schizophrenia.

Methods: A cross-sectional study, conducted between March and July 2016, recruited 196 patients with schizophrenia. The Brief Cognitive Rating Scale (BCRS) and the Morningside Rehabilitation Status Scale (MRSS) were used to measure the severity of cognitive impairment and the level of general functioning in psychiatric patients. Lower scores for both scales indicate a better cognition and functioning respectively. Vitamin D levels of participants were divided into four groups: severe VD deficiency (<10 ng/ml), VD deficiency (10–20 ng/ml), VD insufficiency (20–30 ng/ml), VD sufficiency (>30 ng/ml). Relationships between VD level and cognition and functioning were assessed by analyses of covariance and hierarchical multiple regression, adjusted for age, gender, marital status, education level, sun exposure, physical activity and monthly income.

Results: Severe VD deficiency was found in 22 patients with schizophrenia (11.3%), while 45.6% of patients had VD deficiency. Severe VD deficiency was significantly associated with an increase in MRSS score after adjusting for covariates (Beta = 2.44), however, no significant association was found with the BCRS score.

Conclusion: These findings suggest that severe VD deficiency in patients with schizophrenia might be associated with low general functioning but could not influence cognitive function.

KEYWORDS:

• Vitamin D
• BCRS
• MRSS
• schizophrenia
• cognitive impairment
• general functioning

Acknowledgements

The authors would like to thank Maha Abdel Razzak, Georges Semaha, and Afaf Greij (Masters Students), Dr Sahar Obeid and Miriam Slikhanian for their help in the accomplishment of this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Marouan Zoghbi is an MD and a family medicine specialist. He is a part time faculty member at the Faculty of Medicine at the Saint Joseph University, Beirut, Lebanon.

Chadia Haddad, MPH, is a research assistant at the Psychiatric Hospital of the Cross, Beirut, Lebanon.

Souheil Hallit pursued Pharm.D., MSc, MPH, and PhD. He is an Assistant Professor at the Faculty of Medicine and Medical Sciences, Holy Spirit University (USEK), Jounieh, Lebanon.

Rita Nabout is a Professor at the faculty of sciences, Lebanese university, Fanar, Lebanon.

Myrna Medlej-Hashim is a Professor at the faculty of sciences, Lebanese university, Fanar, Lebanon.

Dory Hachem, MD, is the Head of the psychiatry department at the Psychiatric Hospital of the cross, Beirut, Lebanon. He is a Clinical medical associate at AUBMC, psychiatry department, Beirut, Lebanon.

Jocelyne Azar, MD, is an Assistant Professor at the Faculty of Medicine at the Lebanese American University, Byblos, Lebanon. Azar is a Psychiatrist at the Psychiatric Hospital of the Cross, Beirut, Lebanon.

Additional information

Funding

Special thanks to Pharmaline pharmaceutical company for funding the laboratory tests.