Relationship Between Neonatal Vitamin D at Birth and Risk of Autism Spectrum Disorders: the NBSIB Study

ABSTRACT Previous studies suggested that lower vitamin D might be a risk factor for autism spectrum disorders (ASDs). The aim of this study was to estimate the prevalence of ASDs in 3‐year‐old Chinese children and to examine the association between neonatal vitamin D status and risk of ASDs. We conducted a study of live births who had taken part in expanded newborn screening (NBS), with outpatient follow‐up when the children 3‐year old. The children were confirmed for ASDs in outpatient by the Autism Diagnostic Interview‐Revised and Diagnostic and Statistical Manual of Mental Disorders (DSM)‐5 criteria. Intellectual disability (ID) status was defined by the intelligence quotient (IQ