Researchers from the National Institute of Mental Health and Neuroscience (NIMHANS) in India and the Harvard Medical School in the US looked at the serum vitamin D levels and the brain of 35 schizophrenia patients with an average age of 32.
They found 34 of the patients had sub-optimal levels of serum vitamin D - 83% of which equated to deficiency and 14% insufficiency.
A “significant positive correlation” was also seen between vitamin D and regional grey matter volume in the right hippocampus.
Previous research had suggested vitamin D supplementation may reduce the risk of schizophrenia in infants while another paper linked deficient serum levels with first-episode psychosis.
However this latest paper was the first to look at serum vitamin D levels and hippocampal volume in schizophrenia.
The hippocampus is one of the brain regions with maximum concentrations of vitamin D receptors and the vitamin has been shown to play a critical role in hippocampal cell survival through its neuroprotective effects.
They said the relationship could be due to vitamin D’s impact on neuron-supporting neurotrophin proteins, the nervous system’s interaction with the immune system and the excretion of amino acids.
“Since deficient brain-derived neurotrophic factor and increased oxidative stress have been associated with schizophrenia, these effects mediated by vitamin D through vitamin D receptors could be critical in this disorder,” the wrote in Psychiatry Research: Neuroimaging.
The hippocampus - named after its resemblance to a seahorse - is thought to play a key role in emotions and memory.
Source: Psychiatry Research: Neuroimaging
Vol. 233, Iss. 2, pp. 175–179, doi:10.1016/j.pscychresns.2015.06.006
“Serum vitamin D and hippocampal gray matter volume in schizophrenia”
Authors: V. Shivakumar, S. V. Kalmady, A. C. Amaresha, D. Jose, J. C. Narayanaswamy, S. Mahavir Agarwal, B. Joseph, G. Venkatasubramanian, V. Ravi, M. S. Keshavan and B. N. Gangadhar