Scientists have been searching for the genetic roots of schizophrenia for decades. If a few common genetic glitches, or mutations, were linked to the disorder it could open new strategies for treatment and diagnosis. But new research suggests that schizophrenia is a lot more complicated than many scientists had hoped.

People with schizophrenia have problems with thinking and concentration. They may hear voices others don’t hear or believe their thoughts are being broadcast to the world. Schizophrenia affects about 1 in 100 adults nationwide. Symptoms usually first appear in older teens or young adults.

Three new studies, funded in part by NIH, compared the genomes of thousands of patients with schizophrenia with thousands without the disorder. The research teams found that patients with schizophrenia were more likely to have several different, unusual genetic quirks. Many of the mutations disrupt genes that are important to brain development.

“We’re moving toward an understanding of the causes of the disease, but we’ve only explained a tiny fraction of why people might develop schizophrenia,” said Dr. Pamela Sklar of Massachusetts General Hospital. “Much more work needs to be done to connect the specific genetic changes to the full spectrum of the disorder.”

Vitamin D helps your body absorb calcium, which keeps your bones strong. Some recent studies suggest that taking extra vitamin D can have other health benefits, but the evidence to date has been unclear.

Medical experts held a conference at NIH to take a closer look at the scientific evidence on vitamin D. They reported their conclusions in August 2008.

The strongest evidence suggesting other benefits from more vitamin D is for older people. Several clinical studies found that additional vitamin D can improve bone health and prevent falls in elderly men and post-menopausal women. The experts say they don’t yet have enough information to know if extra vitamin D might help people of other ages. More research is also needed to know if vitamin D can help prevent diseases like diabetes and cancer.

“It’s tempting to think that an essential nutrient is safe at any level—that if some is good, more is better—but that isn’t always true,” said Dr. Paul M. Coates, director of the NIH Office of Dietary Supplements. “There are potential harms associated with high levels of many nutrients.”

Scientific experts will continue to evaluate recent research to decide if current vitamin D recommendations should be revised. Talk to your doctor if you have questions about how much vitamin D you need.