New research has found that newborn babies with vitamin D deficiency are at greater risk of developing attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and schizophrenia. It suggests that mothers supplementing vitamin D during pregnancy could reduce these risks. The University of Queensland, Australia, researchers examined 71,793 people — “the largest population study of its kind” — who were diagnosed with mental health disorders in childhood and early adulthood.