A team of researchers from the University of Newcastle (Australia) has found that increased or decreased levels of vitamin A or retinol may be linked to changes in neural connections in the brain in schizophrenia and some other mental disorders.

The results of the respective study were published in the journal Nature.

Vitamin A is the collective name for chemically similar substances, which include retinol (vitamin A1, axerophthol) and several other retinoids with similar biological activity.

As the authors of the study noted, vitamin A plays an important role in the differentiation, maturation, and synaptic activity of brain cells.

The links between neurons in the brain are thought to be altered in people with schizophrenia and other mental disorders.

The researchers have speculated that this may be due to different levels of vitamin A in the body. In their study, they combined summary statistics from thousands of individual genomes to determine which genetic factors regulate retinol levels in the blood, as well as its absorption and transport.

The scientists then processed the information obtained to identify genomic loci—i.e. participants in the location of specific genes on chromosomes—associated with maintaining high concentrations of retinol in the body; these genes included GCKR and FOXP2.

In addition, genetically predicted MLXIPL mRNA—i.e. messenger RNA—expression in adipose tissue, pancreas, and mammary gland was inversely associated with circulating retinol levels.

According to the authors of this study, this approach enables identifying a greater number of factors in the pathogenesis of mental disorders.

The researchers have suggested that retinol may have neuroprotective effects; this explains its use as a potential adjunct to antipsychotic drugs to treat schizophrenia.