International research led by NICM Health Research Institute at Western Sydney University for the first time systematically reviewed evidence examining nutritional deficiencies in people being treated for psychotic disorders.
Previous research had shown a strong correlation between long-term schizophrenia and various nutritional deficiencies, including vitamins B, C, D and E. However, until now, no one had assessed the full range of nutritional deficiencies, which may be present during the first episode of psychosis.
The researchers assessed 28 studies examining the blood levels of six vitamins and 10 minerals in 2,612 individuals.
All participants were assessed either immediately after presenting with psychotic disorders (such as schizophrenia) for the first time, either prior to antipsychotic treatment or within the early stages of treatment.
The research, published in Schizophrenia Bulletin, found that early psychosis is associated with large deficits in blood levels of critical nutrients, with particularly low levels of vitamin B9 (folate) and vitamin D.
Furthermore, these nutritional deficiencies were found to be associated with worse mental health in young people with early psychosis.
The paper noted: "Deficits in vitamin D and folate previously observed in long-term schizophrenia appear to exist from illness onset, and are associated with worse symptomology. Further research must examine the direction and nature of these relationships (i.e., mediator, moderator, or marker) with clinical status. Future trials assessing efficacy of nutrient supplementation should consider targeting and stratifying for baseline deficiency."
Although the review found no significant differences for other vitamins and minerals, the researchers said that due to a small number of studies that examined these nutrients, they could not be ruled out, and further study was needed to determine their importance.
Nutritional interventions
Schizophrenia affects more than 21 million people worldwide and people with the disorder die 15 to 20 years earlier than the general population. Early detection and treatment of psychotic disorders, such as schizophrenia, is thought to be critical for maximising recovery.
Lead author, NICM postdoctoral research fellow Joseph Firth, said these findings could ultimately contribute to nutritional interventions being added to standard treatment of early psychosis.
"Although just one of many factors, it is important to recognise that nutritional deficiencies could certainly be contributing to the poor physical and mental health outcomes often observed in young people with psychosis," Firth said.
"Our research has found vitamin D and folate deficiencies, previously observed in long-term schizophrenia, exist right from illness onset, and are associated with worse symptoms among young people with psychosis.
"Since both of these nutrients are vital for physical and psychological well-being, this finding emphasises the importance of promoting a healthy diet for young people with psychosis, and potentially suggests adding targeted nutritional supplementation to standard treatment could improve recovery — although this theory has yet to be tested."
Source: Schizophrenia Bulletin
https://doi.org/10.1093/schbul/sbx162
"Nutritional Deficiencies and Clinical Correlates in First-Episode Psychosis: A Systematic Review and Meta-analysis"
Authors: Joseph Firth, et al.