Nutrient deficiencies linked to mental ill health: Review

By Will Chu

- Last updated on GMT

Patients with the long-term mental disorder schizophrenia have low levels of folate and vitamins B12, C, E and D, according to a review, which could not determine a definitive cause and effect relationship.

The research team found the low levels of these nutrients appeared to exist from the onset of illness and were associated with worsening symptoms of the disease.

“Right away, as soon as they are presenting with psychotic symptoms, they have low folate – which is really important for brain health – and low vitamin D, which is also a neuroprotective nutrient; both key factors in people's mood and energy levels,"​ said study lead author, postdoctoral research fellow Joseph Firth​.

"The patients with the lower levels of these nutrients also had the worst mental health. Even if you've got psychosis, people with high levels of these nutrients had better mental health."

The review points to dietary interventions that further emphasise the importance of consuming a good quality diet containing adequate nutrients.

This not only applies to mental health but cardiovascular mortality as the team noted with large-scale studies show linking low levels of both vitamin D and folate to heart-related conditions.

Additionally, multi-ingredient nutraceuticals, which combine various beneficial nutrients to target specific nutritional deficits and neurological processes implicated in psychiatric disorders, may also provide safe and effective adjunctive treatments for first-episode psychosis (FEP).

Genetic role to play?

Through a meta-analysis of 28 study articles, a team from the University of Manchester, Belgium’s KU Leuven University and the University of Western Sydney, were able to show nutrient deficiencies not only exist in long-standing psychosis but also at the onset of FEP.

In the 2612 participants (1221 with FEP and 1391 controls), significant reductions in folate, vitamin D, and vitamin C in people with first-episode psychosis were found when compared with controls.

The team observed that the difference in vitamin D levels between first-episode psychosis and controls was the most pronounced of all nutrients.

Studies of particular note included one that found differences in folate levels resulted from genetic differences in folate metabolism rather than any dietary influences.

Only two studies with small sample sizes found large deficits of vitamin C in first-episode psychosis.

“This is concordant with data suggesting low fruit and vegetable intake in this population,”​ the study said.

“Additionally, a single randomised control trial (RCT) in patients undergoing first antipsychotic treatment has shown 500 milligrams (mg) of vitamin C per day significantly reduces psychiatric symptoms.”

Implications for routine screening

As the review shows, nutritional deficiencies, arising from insufficient intake or absorption of nutrients are now recognised as a risk factor for psychiatric conditions.

Recent attention has focused on patient food intake with folate (B9) and B12 often deficient in schizophrenia patients, where worsening symptom severity were also noted.

In addition, B-vitamin supplementation may significantly reduce symptoms of schizophrenia and reverse some neurological deficits associated with the disorder.

Antioxidant vitamins C and E are also reduced in long-term schizophrenia, potentially contributing to the elevated oxidative stress observed in this population.

“Given the marked reductions in vitamin D and folate observed in FEP compared to nonpsychiatric samples, future research should examine what proportion of individuals with FEP reach clinical thresholds for nutritional deficiencies in comparison to established reference values,” ​the review concluded.

“This in turn could have implications for routine screening of nutritional deficiencies in FEP.“

Source: Schizophrenia Bulletin
Published online ahead of print:
“Nutritional Deficiencies and Clinical Correlates in First-Episode Psychosis: A Systematic Review and Meta-analysis.”
Authors: Joseph Firth, Rebekah Carney, Brendon Stubbs, Scott B Teasdale, Davy Vancampfort, Philip B Ward, Michael Berk, Jerome Sarris

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