"Other recent research has shed some light on very early risk factors for schizophrenia as well. Schizophrenia may be caused by low levels of vitamin D during pregnancy. New research suggests vitamin D deficiencies in utero may be associated with increased risk of schizophrenia later in life. Decades of research have identified numerous risk factors for the condition, one of which is the observation that those born in the winter or spring have a small but significantly increased risk of developing schizophrenia.

Because sun exposure stimulates production of vitamin D in our bodies, deficiencies are more common during the winter and early spring. These convergent clues led researchers to develop the hypothesis that vitamin D deficiency during critical periods of development may be a risk factor for developing schizophrenia."