People with psychotic disorders like schizophrenia might experience some relief if they spend more time in the sun.

The International Early Psychosis Association has reported that research from Norway’s University of Oslo presented during its annual conference in Italy shows that low levels of vitamin D are “associated with increased negative and depressive symptoms” in those patients, according to a statement. The research team was investigating whether low vitamin D could be linked to specific symptoms as well as to cognitive deficits in young patients. In both cases, a few hundred patients were studied; they showed a connection between vitamin D deficiency and negative symptoms and between the vitamin and “cognitive impairments in processing speed and verbal fluency.”

Vitamin D has many benefits, one of them being promoting calcium absorption in the body, according to the National Institutes of Health. It is also crucial in cell and bone growth and in immune function. Because our bodies produce it when our skin is exposed to sunlight, people who spend a lot of time indoors can become deficient in the vitamin, a malady that is common — and even more so in the winter.

Associating sunshine with mental health is not a new idea. Low levels of sunshine, such as what is available during winter months in cold climates, is one of the things that drives seasonal affective disorder, a form of depression that follows the cycle of the seasons, the Mayo Clinic says.

It has also been long suggested that spending more time in the sun could improve mental health. In one article from Issues in Mental Health Nursing, the authors say regulating vitamin D levels in people “with depression and other mental disorders may be an easy and cost-effective therapy which could improve patients’ long-term health outcomes as well as their quality of life.” And there is a treatment called light therapy, or phototherapy, in which patients — such as those suffering from seasonal affective disorder — sit near a device that “gives off bright light that mimics natural outdoor light,” the Mayo Clinic explains.

A link to vitamin D has been drawn even to dementia and migraines.

In the Oslo studies that looked at the link between vitamin D and the severity of negative symptoms in psychotic disorders, the authors concluded that the findings could be a first step toward investigating the connection in a larger sample size, according to the International Early Psychosis Association’s statement. They are also now using MRIs to look at the role of the vitamin in different brain structures.