Researchers have shown before that low vitamin D levels are linked with psychiatric disorders like major depression.

Now, a presentation at the annual meeting of the American Academy of Child and Adolescent Psychiatry signals the importance of testing those who suffer from psychotic symptoms—delusions (fixed and false beliefs) and hallucinations—for vitamin D deficiency.

A group of researchers led by Dr. Barbara L. Gracious, a psychiatrist at Nationwide Children’s Hospital in Columbus, Ohio, presented data at that meeting showing that adolescents who were vitamin D deficient showed a fourfold (400 percent) increased rate of psychotic symptoms, compared to other adolescents with normal vitamin D levels who sought psychiatric treatment at the University of Rochester, in New York.

In other words, in the group of adolescents asking for psychiatric help that Gracious studied, low vitamin D was very, very powerfully connected to the likelihood that they would report symptoms like delusions (like paranoia) or hearing voices or seeing visions.

Delusions and hallucinations are among the most serious symptoms we psychiatrists treat. And the idea that vitamin D deficiency could be so substantially linked to psychotic symptoms is a tantalizing prospect. It suggests that it is time to routinely measure the Vitamin D levels of those complaining of such symptoms.

When vitamin D levels are found to be low, they should, of course, be corrected. Whether or not this will lessen psychotic symptoms remains to be definitively proven.

The vitamin D-mental health connection is particularly interesting given the fact that millions of Americans report symptoms of seasonal affective disorder—depression that typically seems to recur each late fall, or early winter—when exposure to sunlight is limited. Vitamin D plummets, of course, when people are deprived of sunlight.

Gracious’ findings are yet another reason why psychiatry would be wise to drop all resistance to considering the impact of vitamin and nutritional deficiencies of one kind or another on mental well-being.

We know, after all, that Deplin, an altered form of folic acid that can reach the nervous system without being metabolized, shows powerful promise in the treatment of mood disorders. Indeed, Deplin, which I have written about on FoxNews.com before, is already approved by the FDA as a “medical food” that can be used to treat depression. We also know that taking high doses of fish oil can impact mood and may significantly decrease aggression.

These findings on vitamins and other nutrients come at a time when psychiatry’s traditional medications—like serotonin reuptake inhibitors and antipsychotic medications—are under siege. Recent studies have questioned whether many of these agents are any better than placebos. A large study of the very common use of the antipsychotic Risperdal in veterans with post-traumatic stress disorder (PTSD) showed it had essentially no value at all. Yet, such medications can be very, very expensive and can have very serious side effects, including movement disorders, suicidal thinking, cardiac abnormalities and significant weight gain.

I am not saying that traditional psychoactive medications are not important. Used judiciously, with expertise, in the right patients, they can be lifesaving. I’m certain of that. But it is time to open our minds to treatments based on vitamins and other nutrients, as well as other alternative ways of affecting the brain, like repetitive transcranial magnetic stimulation (rTMS, about which I have also written at FoxNews.com).

It is possible that a large percentage of those who now suffer from major depression, for example—even when that depression is severe enough to spark psychotic symptoms—could soon be most effectively treated with psychotherapy, magnetic therapy and nutritional/vitamin therapy. That’s would represent a massive shift in the way psychiatry treats that illness. And other illnesses may be no different.