September 2009 Issue

Supplements for Autism Spectrum Disorder
By Jasmin Ilkay, MPH, RD
Today’s Dietitian
Vol. 11 No. 9 P. 8

Heather Porter clearly remembers the moment when she suspected that her 18-month-old son, Josh, was autistic. A standard developmental screening at her pediatrician’s office made the situation all too clear. “It was like pieces of a puzzle fitting together. I always felt that something was not quite right with my son. Once I realized he displayed signs of autism, I had to act right away,” she explains.

Unfortunately, Porter had to wait months before a team of doctors would agree to diagnose Josh with autism. In the meantime, she did everything she could to minimize the progression of Josh’s autism-related symptoms before doctors could approve him for medical and behavioral therapy.

Immediately, Porter eliminated all gluten and casein from Josh’s diet. Soon thereafter, she took her son to a Defeat Autism Now (DAN) doctor to begin a rigorous treatment plan, including maintenance of a gluten-free, casein-free diet; allergy testing; treatment of intestinal bacterial and/or yeast overgrowth; and nutritional supplementation. DAN is a project of the Autism Research Institute that aims to educate parents and clinicians regarding research, appropriate testing, and safe and effective interventions for autism.

According to the Centers for Disease Control and Prevention, about one in 150 children in the United States is affected by autism. One half to three quarters of these children are being treated with complementary alternative therapies, such as elimination diets, immune globulin therapy, chelation therapy, auditory integration training, facilitated communication, and nutritional supplementation.

Myriad nutritional supplements may be included in an autistic child’s course of therapy. Typical supplements include one or more of the following: various vitamins and minerals, essential fatty acids (EFAs), glutathione (GSH), digestive enzymes, probiotics, and dimethylglycine (DMG).

Essential Fatty Acids
Supplementation with EFAs has grown in popularity during the past couple of years. Except for presumption of deficiency, the mechanism of action to support EFA supplementation for autism spectrum disorder (ASD) is unclear.1

A systematic review of six peer-reviewed articles in the Journal of Autism and Developmental Disorders found insufficient scientific evidence to determine whether omega-3 fatty acid supplements are effective for ASD management.

In 2005, Nordic Naturals, Inc, a supplier of fish oil and EFA nutritional supplements, reported positive results for a pilot trial investigating language and learning skills in children with autism and Asperger’s syndrome. The three-month study provided 18 children aged 3 to 10 with daily supplemental EFAs. The product, Omega-3.6.9 Junior, is made from purified fish oil (omega-3) and purified borage oil (omega-6). Statistical analysis completed at the University of Arizona demonstrated significant increases in all of the children’s language and learning skills.

Apart from this research, other currently available research suggests that EFA supplementation is not helpful. However, for those who wish to supplement, pharmaceutical-grade EFA supplements appear to be safe when taken at the recommended dose.

GSH is a tripeptide composed of three amino acids: cysteine, glycine, and glutamic acid. As a dietary supplement, it is used as an antioxidant to protect the body from toxins and toxic metals. Supporters of GSH supplementation claim that some children with autism have low levels of active GSH because of a disruption in the transsulfuration metabolic pathway.

Any positive correlations from GSH supplementation come from a handful of case studies and personal testimonials. Despite limited evidence, the inclusion of GSH supplements is popular and deserves more research.

Vitamin B12
Vitamin B12 is one of the more important DAN biomedical interventions used today. One thought is that some people with ASD are unable to absorb methylcobalamin B12. According to the United Kingdom-based Web site, others believe that injecting methyl-B12 can help alleviate some of the defects in the transmethylation system. Supporters of methylcobalamin supplementation believe that this can help reduce some or all of the symptoms of autism.

James A. Neubrander, MD, who is considered the “father” of methyl-B12 treatments for autism, reports that 94% of his patients from a private practice show signs of improvement with methyl-B12 injections. Neubrander reports that one injection given every three days can show results within five weeks.

While DAN doctors include methyl-B12 injections in their treatment plans, the lack of evidence prevents other doctors from doing so. Symptoms of excess B12 are currently unknown. While additional trials with more subjects are required to confirm B12’s success, it remains a popular treatment for ASD.

Digestive Enzymes
Digestive enzymes are used to assist with the digestive process and remove toxic compounds from the gastrointestinal (GI) tract.1 They are reported to increase the number of bacteria and enzymes in the GI tract to aid the digestive process. Popular digestive enzymes include papain, pepsin, betaine hydrochloride, and hydrochloric acid. Despite the lack of supportive evidence, enzyme aids or digestive enzymes appear to be used frequently for ASD management.1

Probiotics and Antifungal Agents
Another hypothesis suggests that an overgrowth of candida in the intestine causes some of the symptoms of autism.1 Treatments to minimize yeast overgrowth in the colon include conventional systemic antifungal agents, probiotic agents such as acidophilus and Lactobacillus to alter the bacterial flora of the intestine, and dietary modifications to decrease the substrate for yeast overgrowth.1 While these treatments for ASD remain popular, there are no clinical trials that have been published in peer-reviewed journals validating their use. No negative side effects of probiotic agents or yeast-free diets have been reported, and they remain a popular treatment for autism.

DMG is a derivative of the amino acid glycine and is found naturally in foods such as beans, cereal grains, and liver. It is also manufactured in the body during the metabolism of choline. The use of DMG to treat autism is controversial, and current research shows mixed results. Two double-blind, placebo-controlled studies did not demonstrate differences between DMG and a placebo.1 DMG is reportedly nontoxic with no significant adverse effects.

Vitamins and Minerals
Some people believe that individuals with ASD do not have enough of the right nutrients or have trouble making use of certain nutrients available to them. They believe that these nutritional deficiencies may cause some of the symptoms of ASD as well. Vitamin and mineral supplements included for general deficiency in some autism treatment plans include vitamins A, B6, C, and D, as well as folate and magnesium.

RDs Can Assist and Support
The National Autistic Society states that many autism interventions have been developed, with various claims of success. While certain interventions are helpful to some individuals, they may not be effective for others. With limited peer research available, time is not on the side of patients with autism.

Regardless of current available research, many parents like Porter decide to act immediately to try to slow down the progression, prevent further autistic symptoms, or even try to cure their children. For this reason, it is imperative that health professionals, including dietitians, are aware of the available biomedical treatments so they can assist and support families who decide to use some of the supplements mentioned.

— Jasmin Ilkay, MPH, RD, is the director of nutrition for Fitwize 4 Kids and a freelance writer who specializes in weight management, sports nutrition, eating disorders, and general nutritional counseling.


1. Levy SE, Hyman SL. Novel treatment for autism spectrum disorders. Ment Retard Dev Disabil Res Rev. 2005;11(2):131-142.