ARI Publication 40 – 2013 Version
Duration:
Usually 1-2 months of supplementation are needed to observe an increase in energy level and body
temperature. Supplementation may be needed long term unless the problem with thyroid
development is resolved.
SAFETY CAUTION: Too much thyroid hormone can cause weight loss, anxiety and other
problems, so thyroid levels should be monitored regularly if taking a supplement.
Research:
. There have been several studies of thyroid function and autism.
One study reported a high incidence of thyroid abnormalities in parents of children with autism
Megson MN. Is autism a G-a/pha protein defect reversible with natural vitamin A? Med Hypotheses.
2000 Jun;54(6):979-83.
One study found abnormal thyroid function in young adults with severe autism correlated with
impaired verbal communication.
Nir I et al, Briefreport: circadian melatonin, thyroid-stimulating hormone, prolactin, and cortisol levels in
serum ofyoung adults with autism. J Autism Dev Disord. 1995 Dec;25(6):641-54.
One study found reduced levels of thyroid hormones (TSH) in children with autism (n=41) vs.
controls.
Hashimoto T et al, Reduced thyroid-stimulating hormone response to thyrotropin-releasing hormone in
autistic boys. Dev Med Child Neurol. 1991 Apr;33(4):313-9.
There was also one small study (n=14) that found normal levels of TSH in children with autism, but
that study did not have a control group.
Abbassi Vet al, Triiodothyronine {T3} concentration and therapy in autistic children. J Autism Child
Schizophr. 1978 Dec;8(4):383-7.
One study found that many children with autism have unusually low levels of iodine in their hair,
which possibly suggests a low level in their body and need for more.
Adams JB et al, Analyses oftoxic metals and essential minerals in the hair ofArizona children with
autism and associated conditions, and their mothers. Biol Trace Elem Res. 2006 Jun;110{3}:193-209.
One study found that most children with autism had normal levels of iodine in their urine
(normalized by creatinine) compared to controls, but 25% of the children with autism had unusually
low levels (below the reference range).
Adams JB et al, Nutritional and Metabolic Status ofChildren with Autism vs. Neurotypical Children, and
the Association with Autism Severity, Nutr. Metab {Lond) 2011 Jun 8:8(1):34.
Overall, the reports of abnormal thyroid function in most of the studies are consistent with findings
of low iodine, and it is possible that impaired thyroid function is a cause of some of the symptoms
of autism in some children, especially language impairment and mental retardation.
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