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Dietary Supplements and Autism Ranking: Unable to rate

Dietary supplements to treat autism

Dietary supplements are products intended to improve or enhance the diet.

Dietary supplements include vitamins, minerals, herbals and botanicals, and many other products. They come in a variety of forms including tablets, capsules and powders, as well as drinks and energy bars.

Some people think that some individuals on the autism spectrum have a range of nutritional and metabolic problems. These include low levels of nutrients, high levels of oxidative stress (a chemical state within cells that can increase cellular damage) and difficulties with metabolic processes (such as digestion).

Some people think that these nutritional and metabolic differences may be the cause of some of the core features of autism (such as impaired communication and social difficulties) and related issues (such as challenging behaviours).

They also think that some of these problems can be overcome by taking one or more dietary supplements, sometimes in combination with other therapies such as special diets.

Please note

The National Institute for Health and Care Excellence (NICE) reported that some dietary supplements may have some limited benefits for some children and young people on the autism spectrum beyond the benefits provided to other people. However it also reported that:

"... the evidence was very limited and further randomised placebo-controlled studies are required to corroborate the existing evidence for ... dietary supplements in children and young people with autism".

NICE made the following observations on the use of dietary supplements for adults on the autism spectrum:

"... there is very little evidence regarding safety and efficacy for... vitamins, minerals or supplements for the treatment of autism. Moreover, it is important to bear in mind that ... some dietary supplements can be associated with adverse side effects and/or interact and perhaps interfere with the action of other supplements or prescribed drugs".

Our Opinion

Eating a healthy and varied diet is important for good health. Food and drinks provide a range of nutrients and all vitamins and essential minerals are just that – essential for good health. If too little of any of these nutrients is consumed nutrient deficiencies can occur, which cause ill health.

Consuming too much of any of these nutrients can also cause poor health. It is unusual to consume too much via foods, however taking dietary supplements with high levels of nutrients does carry a risk of nutrient overload. Some diseases (such as cystic fibrosis), some conditions (such as cerebral palsy) and other factors (such as breast-feeding) increase an individual’s needs for some nutrients.

There is evidence that some individuals on the autism spectrum may have nutritional and metabolic problems. For example, some autistic people eat restricted diets which are nutritionally imbalanced and can lead to severe nutrition deficiencies. Symptoms of severe deficiencies include skin rashes, mouth sores, limps, unexplained irritability, eyesight changes and severe ill health. The effects of these can be life threatening and life changing. There is also evidence that some individuals on the autism spectrum may have other nutritional and metabolic problems that have less severe, but behaviourally or medically significant effects.

However, the number of individuals on the autism spectrum who have these problems is not clear. It is also not clear whether these problems or differences are any more common in individuals on the autism spectrum than in other individuals. Possibly, these problems cause or worsen symptoms (of autism or related issues). Or maybe they arise because of autism, or they could be completely unrelated to autism. Nobody knows.

Most dietary supplements provide the same benefits for people on the autism spectrum as they do to people who are not on the autism spectrum. They do not appear to provide any additional benefits to people on the autism spectrum, according to a limited amount of research evidence of sufficiently high quality. Some dietary supplements may make some problems worse for some children and young people on the autism spectrum according to a limited amount of research evidence of sufficiently high quality. There is no high quality research to suggest that any dietary supplements provide any benefits to adults on the autism spectrum.

For details of the research on specific supplements, where it exists, please see vitamins-and-minerals and other-dietary-supplements.

Further research is required to replicate and extend research into those dietary supplements which appear to be effective. Any such research should involve people on the autism spectrum to review the efficacy and ethical basis of the intervention.

Disclaimer

Please read our Disclaimer on Autism Interventions


Audience

According to Bazian (2011), “…nearly a third of people in the UK take some vitamin, mineral or dietary supplement on most days, and about 15% of us report having taken a “high dose” supplement in the last 12 months.”

Healthcare providers often recommend that certain specific groups of people should take specific supplements. For example, according to Bazian (2011),

  • “all pregnant and breastfeeding women should take vitamin D supplements
  • women trying to conceive and women in the first 12 weeks of their pregnancy are recommended to take folic acid supplements, which reduce their child’s risk of neural tube defects such as spina bifida
  • people aged 65 and over should take vitamin D supplements
  • people with darker skin and people who are not exposed to much sun should take vitamin D supplements
  • all children aged six months to five years should be given a supplement containing vitamins A, C and D
  • your GP may also recommend supplements if you need them for a medical condition".

Some people also recommend that some people on the autism spectrum should take one or more dietary supplements. However there is no overall agreement as to which people on the autism spectrum should take which specific supplements.

Aims and Claims

Aims

According to Bazian (2011), “People take supplements for all kinds of reasons, usually relating to their health. They hope these will boost vitality, limit the signs of ageing, extend life, cut the risk of chronic disease such as cancer and treat specific ailments such as arthritis".

Some people think that some individuals on the autism spectrum have a range of nutritional and metabolic problems. These include low levels of nutrients, high levels of oxidative stress (a chemical state within cells that can increase cellular damage) and difficulties with metabolic processes (such as digestion).

Some people think that these nutritional and metabolic differences may be the cause of some of the core features of autism (such as impaired communication and social difficulties) and related issues (such as challenging behaviours).

They also think that some of these problems can be overcome by taking one or more dietary supplements, sometimes in combination with other therapies such as special diets.

Claims

There have been various claims for different dietary supplements for people on the autism spectrum. For example,

  • Some people (such as the Autism Research Institute, 2008) have claimed that taking dimethylglycine results in a range of benefits, including improved behaviour, eye contact, speech and tolerance.
  • Some people (such as Amminger et al, 2007) have claimed that taking omega-3 supplements can lead to a range of benefits including reduced hyperactivity, stereotypy, severe tantrums, aggression or self injurious behaviour.
  • Some people (such as Kałużna-Czaplińska and Błaszczyk, 2012) have claimed that taking a probiotic can lead to improvements in concentration and the ability to carry out orders.
  • Some people (such as Frye et al. (2013)) have claimed that taking folic acid (vitamin B9) supplements, combined with vitamin B12 injections, leads to improvement in a range of areas including expressive communication, personal and domestic daily living skills, and interpersonal, play-leisure, and coping social skills.
  • Some people (such as Wake et al, 2013) have claimed that taking yokukansan, a traditional herbal medicine, may reduce severe irritability/agitation and hyperactivity/noncompliance.

Key Features

Dietary supplements (also called nutritional supplements or nutraceuticals) are products intended to improve or enhance the diet.

Dietary supplements include vitamins, minerals, herbals and botanicals, and many other products. They may come in a variety of forms including tablets, capsules and powders, as well as drinks and energy bars.

Dietary supplements are sometimes combined with other therapies. For example, some people advocate taking one or more dietary supplements, following a particular diet and using detoxification techniques such as chelation.

Types

The following is a list of some common dietary supplements which have been reported to be beneficial to people on the autism spectrum.

Multivitamin/mineral supplements.

Also known as MVMs, these contain a combination of vitamins and minerals, and sometimes other ingredients as well.

Vitamins

  • Vitamin A (also known as retinol) is found in animal sources such as eggs, meat, fish, milk, cheese. Beta carotene, which the body converts into Vitamin A, is found in vegetable sources such as carrots, squashes, and most dark green, leafy vegetables.
  • Vitamin B6 (also known as pyridoxine) is found in beans, nuts, legumes, eggs, meats, fish, whole grains and, fortified breads and cereals.
  • Vitamin B12 is found in virtually all meat products and certain algae such as seaweed. Other sources include fish, dairy products and yeast extract.
  • Vitamin C (also known as ascorbic acid) is found in all fruits and vegetables.
  • Vitamin D is found in some foods, such as oily fish and eggs, and can also be made in the body after exposure to ultraviolet rays from the sun.
  • Folic acid (also known as vitamin B9) is found in small amounts in many foods including broccoli, Brussels sprouts and peas.

Minerals

  • Calcium is found in many foods including dairy products, green leafy vegetables, soybean products, baked goods made from fortified flour and some nuts.
  • Magnesium is found in a wide variety of foods including green leafy vegetables (such as spinach) and nuts, as well as bread, fish, meat and dairy foods.
  • Zinc is found in meat, shellfish, milk and dairy foods such as cheese, bread, and cereal products such as wheatgerm.

Herbals and botanicals

  • Ginkgo biloba is a concentrated extract taken from the leaves of the ginko tree.
  • Luteolin is a flavonoid found in many plants including celery, green pepper and thyme.
  • Quercetin belongs to a group of plant pigments called flavonoids that give many fruits, flowers and vegetables their colour.
  • St. John's Wort is a flowering plant in the family hypericaceae.
  • Yokukansan is a traditional Asian herbal medicine containing a range of rhizomes and roots.

Other

  • Carnitine is the generic term for a group of natural substances such as L-carnitine, which are found in nearly all cells of the body and in certain foodstuffs, such as meat, fish, poultry and milk.
  • Carnosine is a naturally occurring dipeptide, that is, a molecule consisting of two amino acids, found in the human body.
  • Digestive enzymes are proteins such as bromelain, which help to break down food so that the body can absorb it.
  • Dimethylglycine is a derivative of the amino acid glycine found in plant and animal cells and in certain foods such as beans and liver.
  • Glutathione is a substance produced naturally by the liver and is found in fruits, vegetables and meats.
  • Omega-3 is an essential fatty acid that cannot be created within the human body. It must therefore be obtained from foodstuffs, such as some plant seeds and fish-oil.
  • Probiotics are live microorganisms thought to be beneficial to the host organism. Prebiotics are natural substances in some foods that are supposed to encourage the growth of probiotics.

Dosage

The dosage will depend to a certain extent on the characteristics of the specific dietary supplement being used (trace elements such as zinc should only be given in very, very small doses) and the characteristics of the individual taking the supplement (children generally need smaller doses than adults).

However, care should be taken not to exceed recommended dosages set by organisations such as the Food Standards Agency or the Medicines and Healthcare Regulatory Agency. This is because high dosages of some substances can cause problems. For example, according to Bazian (2011), levels of vitamin C above 1,000mg a day can cause abdominal pain and diarrhoea.

Dietary supplements in the UK carry labels denoting the percentage of the Recommended Daily Allowance (RDA) contained in the product.

Cost and Time

Costs

The cost of buying a dietary supplement depends on a range of factors including the type of supplement, the quantity you buy, the supplier, delivery charges etc.

We found a wide range of suppliers providing multivitamin supplements for a wide range of prices when we did an online search on 18 January 2017. Prices varied from £3.50 to £12.99 for 100 tablets.

In the UK, it is sometimes possible to obtain free NHS prescriptions for specific dietary supplements if you have certain medical conditions (such as diabetes) or you are a member of an exempt group (such as being under 16 or over 65).

Time

Most dietary supplements are designed to be taken one or more times a day, often before mealtimes.

The length of treatment depends on a range of factors including the type of supplement and the characteristics of the individual being treated. For example, Adams (2007) states that the use of multivitamin supplements is “lifelong, although improving diet and healing gut may reduce the need for supplementation”.

However we would strongly recommend that you review your use of dietary supplements on a regular basis with a responsible health professional such as a dietitian, GP or pharmacist. This is because you are likely to experience some harm if you take vitamins in large amounts over long periods of time.

 

Risks and Safety

Hazards

The quality of dietary supplements can vary enormously depending on the specific supplement, the manufacturer, the ingredients and the manufacturing process.

Although the doses of vitamins and minerals found in most supplements are thought to be safe, very high levels can be harmful and you are likely to experience some harms if you take vitamins in large amounts over long periods of time

There are some potential hazards associated with specific dietary supplements. For example, the following symptoms have been reported with the following vitamins.

  • According to the Office of Dietary Supplements (2006), “Toxic symptoms can also arise after consuming very large amounts of preformed vitamin A over a short period of time. Signs of acute toxicity include nausea and vomiting, headache, dizziness, blurred vision, and muscular uncoordination”
  • According to the Food Standards Agency (2003), “The key adverse effect, for vitamin B6 is neuropathy, which has been demonstrated in both humans and laboratory animals. The effect occurs after consumption of high doses and/or long duration. Generally the symptoms are reversible once the exposure is stopped but in some cases involving high doses, the effects are irreversible. Progressive sensory ataxia occurs, presenting initially as unstable gait and numb feet, then numbness in the hands, followed by profound impairment of position sense and vibration sense in the distal limbs. The senses of touch, temperature and pain are less affected.”
  • According to the Office of Dietary Supplements (2006), “Vitamin C toxicity is very rare.... However, amounts greater than 2,000 mg/day are not recommended because such high doses can lead to stomach upset and diarrhea.”
  • According to the Office of Dietary Supplements (2005), “Vitamin D toxicity can cause nausea, vomiting, poor appetite, constipation, weakness and weight loss. It can also raise blood levels of calcium, causing mental status changes such as confusion.”

Contraindications

There are no known contraindications (something which makes a particular treatment or procedure potentially inadvisable) for most dietary supplements. However, some dietary supplements may be contraindicated for the following groups of people or under the following circumstances. For example:

  • According to the Office of Dietary Supplements (2013), carnitine supplements can sometimes cause “muscle weakness in uremic patients and seizures in those with seizure disorders.”
  • According to the National Center for Complementary and Alternative Medicine (2012) “... probiotics usually have few side effects. However, the data on safety, particularly long-term safety, are limited, and the risk of serious side effects may be greater in people who have underlying health conditions.”
  • According to the Office of Dietary Supplements (2007) vitamin B6 can reduce the effectiveness of some medications including anticonvulsants such as sodium valproate, carbamazepine and phenytoin.
  • According to the Office of Dietary Supplements (2016) there are no known adverse effects of taking vitamin B12 supplements, although it does have the potential to interact with certain medications such as chloramphenicol, some proton pump inhibitors, and some H2 receptor antagonists.
  • Tsai et al examined the interaction of a wide range of herbs and dietary supplements (HDS) with a wide range of medications in 2012 and reported“HDS products containing St. John's Wort, magnesium, calcium, iron, ginkgo had the greatest number of documented interactions with medications. Warfarin, insulin, aspirin, digoxin, and ticlopidine had the greatest number of reported interactions with HDS.”

Individuals on the autism spectrum or their carers who have concerns about their or their child’s diet should seek advice from a responsible health professional such as a GP or pharmacist. This may lead to a referral to a dietitian, in particular one with experience of working with individuals on the autism spectrum.

Notes: ataxia (loss of coordination); distal (below the knee); uremic (chronic kidney disease).

Suppliers and Availability

Suppliers

Dietary supplements are available from a wide range of suppliers including health food stores, chemists and pharmacies, professional health care providers and online stores.

The quality of dietary supplements varies enormously depending on the supplier, the supplement, the ingredients and manufacturing process.

If you are contemplating taking dietary supplements, you should seek advice from a GP, pharmacist or dietitian. The British Dietetic Association has information about qualified dietitians in the UK.

For children and adults who are not eating a varied and sufficient diet, for example, avoiding food groups, or eating a very restricted diet, a dietitian can help by assessing dietary intake and advising on testing and supplementation where necessary.

All professionals involved with adults and children on the autism spectrum should watch for potential nutritional problems particularly if their diets are restricted.

Credentials

There are no formal, internationally validated registered qualifications for most people who provide dietary supplements.

However, in the UK, the quality of dietary supplements is regulated by the Medicines and Healthcare Products Regulatory Agency, if they ‘contain a pharmacologically active substance or make medicinal claims (claims to treat or prevent disease, or to interfere with the normal operation of a physiological function of the human body) ...’

In the UK certain supplements are considered to be foods and will therefore be regulated under general food laws by the Food Standards Agency and Department of Health. Others will be regulated as a medicine by the Medicines and Healthcare Regulatory Agency (MHRA).

All herbal medicines placed on the UK market must have a Traditional Herbal Registration (THR)10 or a marketing authorisation (previously known as a product licence). The MHRA now defines individual herbal medicines as either registered traditional herbal medicines or licensed herbal medicines.

In the USA dietary supplements are not classed as drugs, but the Food and Drug Administration is responsible for taking action against any unsafe dietary supplement product after it reaches the market.

History

According to Nye and Brice (2005)

“The use of mega-vitamin intervention began in the early 1950s with the treatment of schizophrenic patients (Rimland 1964). Pyridoxine (vitamin B6) was first reported to improve speech and language in some children diagnosed with "autism syndrome" when Bönisch observed that some participants showed improvement in speech and language (Bönisch 1968). Other researchers (Ananth 1973; Bucci 1973; Greenberg 1970) also reported improved behavioural or biochemical functioning with schizophrenic participants given large doses of vitamin B6. These studies, along with individual anecdotal observations of parents and professionals, led Rimland and colleagues (Rimland 1978) to assess the effectiveness of this orthomolecular treatment. Rimland had recognised that large doses of vitamin B6 produced several undesirable side effects (including irritability, hypersensitivity to sound and enuresis, which could be countered with doses of magnesium [Mg]). Over the next 19 years, a number of investigators published studies in which attempts had been made to assess the effects of vitamin B6-Mg on a variety of characteristics such as verbal communication, non-verbal communication, interpersonal skills, and physiological function, in individuals with autism”.

Current Research

There is evidence that some individuals on the autism spectrum may have nutritional and metabolic problems. For example, some autistic people eat restricted diets which are nutritionally imbalanced and can lead to severe nutrition deficiencies. Symptoms of severe deficiencies include skin rashes, mouth sores, limps, unexplained irritability, eyesight changes and severe ill health. The effects of these can be life threatening and life changing. There is also evidence that some individuals on the autism spectrum may have other nutritional and metabolic problems that have less severe, but behaviourally or medically significant effects.

However, the number of individuals on the autism spectrum who have these problems is not clear. It is also not clear whether these problems or differences are any more common in individuals on the autism spectrum than in other individuals. Possibly, these problems cause or worsen symptoms (of autism or related issues). Or maybe they arise because of autism, or they could be completely unrelated to autism. Nobody knows.

Most dietary supplements provide the same benefits for people on the autism spectrum as they do to people who are not on the autism spectrum. They do not appear to provide any additional benefits to people on the autism spectrum, according to a limited amount of research evidence of sufficiently high quality. Some dietary supplements may make some problems worse for some children and young people on the autism spectrum according to a limited amount of research evidence of sufficiently high quality. There is no high quality research to suggest that any dietary supplements provide any benefits to adults on the autism spectrum.

For details of the research on specific supplements, where it exists, please see http://researchautism.net/vitamins-and-minerals and http://researchautism.net/other-dietary-supplements.

NICE

The National Institute for Health and Care Excellence (NICE) is a UK government body which supports healthcare professionals and others to make sure that the care they provide is of the best possible quality and offers the best value for money.

NICE made the following observations on the use of dietary supplements for adults on the autism spectrum. “... there is very little evidence regarding safety and efficacy for exclusion diets, vitamins, minerals or supplements for the treatment of autism. Moreover, it is important to bear in mind that ... some dietary supplements can be associated with adverse side effects and/or interact and perhaps interfere with the action of other supplements or prescribed drugs”. (NICE, 2012)

NICE also reported that some dietary supplements may be beneficial for some children and young people on the autism spectrum. However it also reported that “... the evidence was very limited and further randomised placebo-controlled studies are required to corroborate the existing evidence for ... dietary supplements in children and young people with autism”. (NICE, 2013).

Future Research

There is a need for further research into the use of dietary supplements for people on the autism spectrum. Specifically there is a need for studies which:

  • Use more robust methodology, for example, large-scale, randomised, double-blind trials carried out on several sites
  • Replicate and extend existing research into those dietary supplements which appear to be effective
  • Identify which individuals are most likely to benefit from which supplements
  • Any future research should involve people on the autism spectrum to review the efficacy and ethical basis of the intervention.

Other Reading

This section provides a select list of publications on the topic of dietary supplements. For more publications on this topic please see our publications database.

If you know of any other publications we should include in this section or in our publications database please email info@researchautism.net with the details.

Please note that we are unable to supply publications unless we are listed as the publisher. However, if you are a UK resident you may be able to obtain them from your local public library, your college library or direct from the publisher.

Related Other Reading


Personal Accounts

This section provides details of personal accounts of the use of dietary supplements for people on the autism spectrum.

Personal accounts can be useful sources of information about the intervention but are not as scientifically valid or reliable as research trials. This may be especially true where the accounts are published by an organisation which might gain a financial advantage from the take-up of the intervention.

Please note that the views expressed in these personal accounts do not necessarily represent the views of Research Autism.


There are numerous personal accounts of the benefits of different dietary supplements for people on the autism spectrum.

Additional Information

For reliable information on healthy eating and dietary supplements go to the NHS Choices webpages: http://www.nhs.uk/pages/home.aspx or check out British Dietetic Association Food Facts Sheets – which include fact sheets on supplements, vitamin D, calcium, probiotics, iodine, autism, diet and behaviour and learning, and more: https://www.bda.uk.com/foodfacts

Related Additional Information


Updated
31 Oct 2017
Last Review
01 Apr 2017
Next Review
01 Apr 2020