Vitamin D deficiency in newborns is associated with increased risk of ADHD, schizophrenia, and autism

In the world's largest population study of its kind, researchers from Aarhus University, University of Queensland, and Statens Serum Institut have demonstrated that newborns with vitamin D deficiency have an increased risk of later developing mental disorders such as ADHD, schizophrenia, and autism.

The researchers analyzed data from 1.4 million people, including 82,600 individuals who were diagnosed with a mental disorder during childhood and early adulthood.

"The study confirms our hypothesis that low vitamin D levels during pregnancy can affect fetal development, and it shows that there is especially a connection with the conditions we have examined, which are believed to be related to early brain development - namely ADHD, schizophrenia, and autism," says Professor and Center Director Preben Bo Mortensen from the National Centre for Register-based Research at Aarhus University.

Confirms previous results

Professor John McGrath from the University of Queensland in Australia, who holds a Niels Bohr Professorship at Aarhus University, has led the study, which is based on data from Danish health registries.

The study examined six mental disorders, including depression, bipolar disorder, schizophrenia, ADHD, autism spectrum disorders, and anorexia.

The connection between low vitamin D levels at birth and increased risk of mental disorders was most evident for schizophrenia, ADHD, and autism.

The study confirms results from previous studies but differs in both scope and method.

"We based the study on the so-called IPSYCH cohort, where we combined data from the Danish health registries with analyses of blood samples from the Danish Neonatal Screening Biobank. This gave us a unique data foundation that does not exist elsewhere in the world," explains Preben Bo Mortensen.

Independent factor

Several previous studies of both humans and animals have shown that vitamin D plays an important role in brain development in fetuses and young children.

Preben Bo Mortensen emphasizes that mental disorders are complex conditions with many genetic and environmental causal factors.

"But our study suggests that vitamin D is an independent factor that can contribute to the risk, and which we actually have an opportunity to influence," he says.

There are already guidelines from the Danish Health Authority that pregnant women and children up to the age of four should take vitamin D supplements.

"Our research confirms the importance of these recommendations, and we encourage people to follow them," says Preben Bo Mortensen.

Behind the research - more information 

Study type: Epidemiological study

Collaborators: University of Queensland and Statens Serum Institut

External funding: The Danish National Research Foundation, The Lundbeck Foundation

Potential conflict of interest: none

Link to scientific article published in The Lancet Psychiatry: https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(25)00099-9/abstract

Contact

Professor Preben Bo Mortensen
Aarhus University, Department of Public Health - National Centre for Register-based Research 
pbm.ncrr@au.dk 
Phone: +45 87165359