Schizophrenia linked to mother’s lack of sunlight. I blinked to speculation about this link last summer, based on the observation that there is more of a disparity between winter and summer birth rates of schizophrenics in higher latitudes than nearer the equator, and an increasing likelihood with darker skin. Speculation was that the mediating factor is vitamin D, which the body needs sunlight to produce and which requires more sunlight in darker-skinned individuals than light-skinned. Now experiments with rats show that vitamin D deprivation produces neurobiological and behavioral changes which might be analogues to those seen in human schizophrenia. Because vitamin D can cause birth defects, pregnant women should not respond to this news by starting to take large amounts of it, but plenty of time outdoors on sunny days wouldn’t hurt. New Scientist