Thyroid hormone T4 is responsible for regulating the metabolism in the body. A lack of this hormone, or Hypothyroidism (underactive Thyroid) is caused by a lack of Iodine in the diet, and can cause metabolism to reduce dramatically causing weight gain, lethargy and circulatory problems.
T4 deficiency is more pronounced during pregnancy, when the body makes higher demands on diet. Researchers from the Houston Methodist Neurological Institute and Erasmus Medical Centre tested 4,000 Dutch mothers and their children. Previous smaller scale research in this field has tenuously hinted at a link.
The research demonstrated that the lower the levels of the hormone T4 in the mother’s system, the more pronounced the symptoms of Autism were likely to be in the child.