Source: The Autism Community in Action (TACA)

At a minimum, most children with autism need the recommended daily allowances (RDA) of vitamins and minerals missing from their bodies and/or not being absorbed naturally via food.

Common supplements
The following are the most commonly used supplements for individuals with ASD. Dosages are set by the doctor, based on weight, preferably after testing shows a need.

Calcium is a MUST if the child is on a dairy-free diet. There is not enough calcium in any multivitamin, so this must be given in a separate supplement.
DMG/TMG raises glutathione and helps speech production.
Enzymes aid digestion.
Essential Fatty Acids (EFAs), Omegas 3 and 6 (DHA, EPA) aid in brain development and relieve depression.
Folic/Folinic acid aids oxidative stress/glutathione/methylation.
Iron should be given only if tests show a need.
Magnesium aids sleep and anxiety.
Melatonin aids sleep.
Probiotics improve immune and gut function.
Vitamin A suppresses viruses, and aids the thyroid. It’s found in cod liver oil. If high dose is prescribed, take with Vitamin K.
Vitamin B12 (MethylB12, MB12, Methylcobalamin) is usually given in shots. Hydroxy B12 is used if MB12 isn’t tolerated.
Vitamin B6 is the most widely used supplement with ASD patients. It helps with detoxification, glutathione, neurotransmitters, blood and enzymes. Take with magnesium.
Vitamin C aids the immune system and detoxification.
Vitamin D3 aids calcium absorption, boosts the immune system, and is anti-inflammatory.
Vitamin E aids the immune system and detoxification.
Vitamin K should be used if the patient is on high-dose Vitamin A/cod liver oil.
Zinc stimulates appetite and improves the immune system.
Glutathione IV is most effective to aid detoxification, but Setria oral GSH has proven effective also.
Neurotransmitter calmers (GABA, taurine, EFAs, B6, inositol, 5HTP, Magnesium, l-theanine) ease anxiety. More on anxiety at
Carnitine provides mitochondrial support to make energy.
NADH (B3) and Ribose aid oxidative stress/glutathione/methylation.
N-Acetyl-Cysteine (NAC) is a form of cysteine, an amino acid that is the rate-limiting factor in the production of glutathione. N-Acetyl-Glycine may be used if the patient doesn’t tolerate NAC.

For more on dosages, see Summary of Dietary, Nutritional, and Medical Treatments for Autism (pdf)