Vitamins, Minnerals and Autism


Surveys show that many parents of children with Autism Spectrum Disorders give their children vitamin supplements. While there are occasionally severely abnormal diets of children with autism, medical nutrition experts generally say that most children with ASDs receive enough vitamins through their diet
for good health. However, parents often believe supplements will help with autism symptoms. Where did this idea come from, and what is the evidence?

In 1970 when Linus Pauling announced in his book Vitamin C and the Common Cold that taking 1,000 mg of vitamin C daily (16 times the recommended daily amount for vitamin C) will reduce the incidence of colds by 45% for most people but that some people need much larger amounts, megavitamins took the nation by storm. Pauling had no background in medicine nor any evidence that what he claimed was actually true. It was a purely theoretical idea. In 1976 (Vitamin C, the Common Cold and the Flu) he suggested even higher dosages. A third book, Vitamin C and Cancer (1979) claimed that high doses of vitamin C may be effective against cancer. There is no evidence this is correct

Bernard Rimland, the parent and well know advocate for individuals with autism, obtained his PhD in experimental psychology and research design, from Pennsylvania State University. Around time Pauling was promoting mega-vitamin C dosages for colds and cancer, Dr. Rimland began suggesting parents use megavitamins and minerals to treat children with autism. He conducted numerous surveys asking parents to report treatments they were using with their children with ASDs and their effectiveness. He reported the survey results for minerals and vitamins in the Autism Research institute newsletter. In an article published by the Assn for Comprehensive NeuroTherapy in “Latitudes”, vol. 1, no. 3&4, Dr. Rimland wrote, “All eighteen studies known to me in which vitamin B6 has been evaluated as a treatment for autistic children have provided positive results”. The problem was that most of those studies to which Dr. Rimland referred were like the parent surveys he conducted, or were poorly controlled studies. They would not pass minimum standards of a controlled clinical trial of any FDA approved medicine. The question remains, what is the evidence for vitamin or mineral abnormalities in autism spectrum disorders and to what extent do supplements overcome autism symptoms?

I recently reviewed all published clinical studies abstracted in PubMed, the National Institute of Health database, covering the period 1980 to the present searching for specific key words. PubMed is widely accepted as the authoritative source of information regarding published medical research on nearly any topic. It does not include book chapters, magazine articles, or newsletter reports that are not peer reviewed by experts in the field. I searched under “Autism” in combination with any of the following: Vitamins A, B6, B12, Bc (Folic acid), Niacin, C, D, E or K. Those vitamins include the most commonly recommended vitamin supplements recommended by individuals and groups promoting vitamin and mineral supplements in autism.

GENERAL VITAMIN-MINERAL STUDIES: Shearer et. al. (1982) studied calcium, magnesium, zinc, copper, lead, and cadmium concentration in scalp hair samples from 12 autistic children and 12 nonautistic controls. The only statistically significant difference between concentrations of minerals in the hair from the two groups was a 62% decrease in cadmium in the hair of autistic children. The authors concluded the cadmium difference was not medically significant. Wecker et. al.(1985) studied trace element concentrations in hair of autistic children compared with matched controls. The autistic population had significantly lower levels of calcium, magnesium, copper, manganese and chromium and higher levels of lithium as compared to sex- and age-matched controls. There have been no replications or similar studies for the past 20 years.

VITAMIN A: Two single case reports have appeared in the research literature over 20 years involving Vitamin A deficiency in autism. In both cases, visual problems were reported and in one an 8 year old also developed a limp after living on a diet composed entirely of French Fries. There have been no studies of Vitamin A supplements alone.

VITAMIN B6 and MAGNESIUM: Kleijnen and Knipschild (1991) surveyed all published studies of magnesium, Vitamin B6 and other vitamins and minerals up to 1990. In some autistic children positive results were reported with very high dosages of vitamin B6 and magnesium. Because of serious methodological problems they concluded further evidence is needed before clear conclusions could be drawn. Pfeifer (1995) conducted a similar review of B6-magnesium studies and found that while many reported a favorable response to vitamin treatment, serious methodological shortcomings made it difficult arrive at a clear conclusion about the validity of the authors’ conclusions. Errors included imprecise outcome measures, lack of double blind conditions, small samples and short-term measures of effects. Adams and Holloway (2004) found that autistic children had substantially
elevated evels of B6 compared to a control group of typical children. They suggested high vitamin B(6) levels are consistent with reports of low levels of related enzymes in autism. Nye and Brice (2005) surveyed 33 studies dealing with Vitamin B6 and Magnesium in autism under the auspices of the highly regarded Cocharane Collaborative. Only three met minimal standards for a controlled scientific study. The Tolbert (1993) study provided insufficient data to conduct a secondary analysis. Another study (Findling 1997) yielded no significant differences between B6-magnesium and placebo groups on measures of social interaction, communication, compulsivity, impulsivity, or hyperactivity. Kuriyama (2002) (n=8) measured IQ and 'Social Quotient' and found a small but statistically significant benefit for IQ but not “social quotient”. Strambi (2006) found no differences in magnesium inside blood cells between controls and children with autism; however, autistic children and children with other autistic spectrum disorders had significantly lower plasma concentrations of Mg than normal subjects. Since plasma includes serum and blood cells, that must mean serum levels are lower. The implications of this difference are unclear.

VITAMIN B12: Pasca et. al, (2006) reported in a sample of 12 children with autism Vit B12 blood levels were “suboptimal”. There have been no published reports of effects of B12 supplements in children with ASDs.
VITAMIN Bc (Folic Acid): Some years ago it was suggested there may be folic acid deficiencies in Fragile X syndome, approximately 25% of whom also have autism. Eto, (1992) studied levels of folate of children with autism and matched controls and found they were not statistically different. The benefits of folic acid supplements in Fragile X syndrome have been equivocal in controlled studies (Laxova, 1994). There have been no published studies of Folic Acid supplements in autism.

NIACIN: Niacin is a component of the Vit B complex. There have been no reports of niacin deficiency or supplementation in ASDs.

VITAMIN C: Dolske (1993) studied effect of Vitamin C on behavior of 18 children with autism in a residential school. Ratings were double blind using the Ritvo-Freeman Autism Scale (seldom used today). Total scores and also sensory motor scores indicating a reduction in symptom severity associated with the ascorbic acid treatment. There have been no replications of this study or other Vitamin C studies since then.

VITAMIN D: There have been no reports of Vit D deficiency or supplementation in ASDs.

VITAMIN E: Corbett et. al. (2006) studied differences in a large number of proteins in children with autism and matched controls. Apo B-100 and apo A-IV were higher in children with high compared to low functioning autism. Apos are involved in the transport of lipids, cholesterol and vitamin E. There have been no reports of Vit E supplements in ASDs.

VITAMIN K: There have been no reports of Vit K deficiency or supplementation in children with ASDs.


1. There is one published study reporting elevated Vit B6 in blood of children with autism and one study reporting suboptimal Vit B12 in a small group of children with autism. One study suggested a protein related to Vit E may be abnormal in autism, but Vit E was not measured. Otherwise there is no evidence of vitamin abnormalities associated with autism.

2. There are several reports suggesting B6-magnesium supplements may improve autism symptoms in some children, though the results are difficult to interpret because of problems with the research. One study of 18 children with ASD in a residential school suggested Vit C supplements may have beneficial effects, but there have been no replications of that study in the past 14 years.

3. There have been no published reports of controlled supplement trials with children with autism spectrum disorders with Vitamins A (two single cases of children with grossly abnormal diets), B12, Folic Acid, Niacin, D, E or K.

Pasca, SP (2006) Life Sci 78:2244-8.
Laxova, R (1994) Adv Pediatr. 1:305-42.
Eto, I. (1992) J. Autism Dev Disord. 22:295-308.