Vitamin D to Prevent Autism in Newborn Siblings

• Autism or no autism develops [ Time Frame: Child assessed at 3 years of age ] [ Designated as safety issue: No ]
  The child will be screened by an MCHAT interview at 18 months of age, and by a questionnaire, the PDD Behavioral Inventory at 3 years of age to determine whether the child has developed autism or not.
  
  

• The mother or child will not develop side effects from vitamin D. [ Time Frame: During pregnancy and the 3 years of the child's development ] [ Designated as safety issue: Yes ]
  Mother will be followed by blood and urine screening for hypercalcemia and hypercalciuria which is the primary side effects of too much vitamin D.
  
  

Drug: Vitamin D3
4000 IU D3 capsule oral/day for entire pregnancy. 6000 IU D3/day during breastfeeding. If not breast feeding, baby gets 400 IU D3/day. Baby increased to 1000 IU D3/day at one year of age.
Other Name: Cholecalciferol

The incidence of autism is increasing. Also, women of childbearing age are increasingly found to be insufficient/deficient in vitamin D. Vitamin D is a neurohormone which is important for development of the child, especially of the child's brain. The primary source of vitamin D is from the sun through one's skin. People have been avoiding the sun because of skin cancer, because of increasing TV watching, computer viewing and wearing clothes that cover most of the body. This approach will study whether making the pregnant mother, whose child is at risk for autism because of a previous child with autism, replete with vitamin D will prevent that recurrence of autism in the newborn sibling.