The study, led by Professor John McGrath from Aarhus University and the University of Queensland, found that newborns with vitamin D deficiency had a 44 per cent increased risk of being diagnosed with schizophrenia as adults, compared to those with normal Vitamin D levels.

Professor McGrath, who has a Niels Bohr Professorship at the National Centre for Register-based Research at Aarhus University, says the new study is based on 2602 individuals. The study confirms a previous study that also found an association between neonatal vitamin D deficiency and an increased risk of schizophrenia. The findings support the hypothesis that the risk of schizophrenia could be reduced with the treatment of vitamin D deficiency during the earliest stages of life.

“Schizophrenia is a group of poorly understood brain disorders characterised by symptoms such as hallucinations, delusions and cognitive impairment,” he says.

“As the developing fetus is totally reliant on mother’s vitamin D stores, our findings suggest that ensuring pregnant women have adequate levels of vitamin D may result in the prevention of some schizophrenia cases, in a manner comparable to the role folate supplementation has played in the prevention of spina bifida.”

8 per cent of all schizophrenia-cases in Denmark

The team made the discovery by analysing vitamin D concentration in blood samples taken from Danish newborns between 1981 and 2000 who had gone on to develop schizophrenia as young adults.

The researchers compared these samples to those of people matched by sex and date of birth who had not developed schizophrenia.

According to John McGrath, schizophrenia is associated with many different risk factors, both genetic and environmental, but the new research suggests that neonatal vitamin D deficiency could possibly account for about 8 per cent of schizophrenia cases in Denmark.

“Much of the attention in schizophrenia research has been focused on modifiable factors early in life with the goal of reducing the burden of this disease. Previous research identified an increased risk of schizophrenia associated with being born in winter or spring and living in a high-latitude country, such as Denmark,” he says.

“We hypothesised that low vitamin D levels in pregnant women due to a lack of sun exposure during winter months might underlie this risk, and investigated the association between vitamin D deficiency and risk of schizophrenia.”

Professor McGrath also led a Dutch 2016 study that found a link between prenatal vitamin D deficiency and increased risk of childhood autism traits.

“The next step is to conduct randomized clinical trials of vitamin D supplements in pregnant women who are vitamin D deficient, in order to examine the impact on child brain development and risk of neurodevelopmental disorders such as autism and schizophrenia”

Further information

Read article: “The association between neonatal vitamin D status and risk of schizophrenia” 

The research was published in Scientific Reports and was supported by the organisations: the Lundbeck Foundation and Danish National Research Foundation, the Stanley Medical Research Institute,  Australia’s National Health and Medical Research Centre, The University of Queensland, the Clem Jones Centre for Ageing Dementia Research, and the European Research Council.