A review of worldwide studies discovered that taking high-dose B-vitamins, such as B6, B8 and B12, alongside treatment, could reduce symptoms of the mental illness more than standard treatments alone.
“We can see that B-vitamins effectively improve outcomes for some patients,” said lead author Joseph Firth, based at the University of Manchester’s Division of Psychology and Mental Health.
“This could be an important advance, given that new treatments for this condition are so desperately needed.”
Schizophrenia affects around 1% of the population and is among the most disabling and costly long-term conditions worldwide, according to experts.
Currently, treatment is based around the administration of antipsychotic drugs.
Although patients typically experience remission of symptoms such as hallucinations and delusions within the first few months of treatment, long-term outcomes are poor and 80% of patients relapse within five years.
For the latest body of research, which was funded by The Medical Research Council and University of Manchester, researchers reviewed randomised clinical trials reporting effects of vitamin or mineral supplements on psychiatric symptoms in people with schizophrenia.
They identified 18 clinical trials with a combined total of 832 patients receiving antipsychotic treatment for schizophrenia.
Vitamin B interventions which used higher dosages or combined several vitamins were consistently effective for reducing psychiatric symptoms, whereas those which used lower doses were ineffective.
Researchers said vitamin B supplements may be most beneficial when implemented early on, as they were most likely to reduce symptoms when used in studies of patients with shorter illness durations.
Firth added: “High-dose B-vitamins may be useful for reducing residual symptoms in people with schizophrenia, although there were significant differences among the findings of the studies we looked at.”
“There is also some indication that these overall effects may be driven by larger benefits among subgroups of patients who have relevant genetic or dietary nutritional deficiencies.”
Co-author Jerome Sarris, Professor of Integrative Mental Health at Western Sydney University, added: “This builds on existing evidence of other food-derived supplements, such as certain amino-acids, been beneficial for people with schizophrenia.
“These new findings also fit with our latest research examining how multi-nutrient treatments can reduce depression and other disorders.”
The research team said more studies are needed to discover how nutrients act on the brain to improve mental health, and to measure effects of nutrient-based treatments on other outcomes such as brain functioning and metabolic health.
The research was published in the journal Psychological Medicine.
Naturally, vitamin B6 is found in a wide variety of foods including: pork, chicken, turkey, fish, bread, whole cereals, eggs, vegetables, soya beans, peanuts, milk and potatoes.
Vitamin B12 is also found in meat and fish (such as salmon and cod), as well as cheese, eggs and some fortified breakfast cereals.