Autism Therapy: vitamin A (retinoic acid)

What is it?

Vitamin A is a fat-soluble vitamin that is required by the body and found naturally in many foods. Vitamin A is found in liver, sweet potato, carrots, kale, butter, spinach, leafy vegetables, pumpkin, and other fruits and vegetables. Vitamin A helps the body have healthy vision, skin, and bones ^{(1, 2)}. Vitamin A is also believed to help with sensory perception, language, and attention ⁽³⁾.

Vitamin A can be bought in different forms: carotenoids, retinyl acetate, retinol, palmitate, or cod liver oil ⁽⁴⁾. Carotenoids are also found in foods can be broken down in the body to form vitamin A.

What's it like?

Vitamin A therapy is considered a complementary and alternative therapy (CAM). During vitamin A therapy, people with autism take vitamin A supplements including cod liver oil. In rare cases of severe deficiency, doctors may give vitamin A intravenously.

Few studies have been performed that look at vitamin A therapy and autism. Doses in one study ranged from 3,500 to 5,000 international units (IU) per day in a 10-year-old boy, to 0.85 milliliters of cod liver oil daily for a 14-week-old infant ⁽³⁾.

If you choose vitamin A as an alternative therapy, ask your child's doctor what dose is appropriate for your child.

What is the theory behind it?

Some people with autism may not have enough vitamin A in their diet ^{(5, 6)}. The low amount of vitamin A in their diet may occur because some children with autism have poor nutrition as a result of eating problems. In one case study, an 8 year-old boy had been eating only fried potatoes and drinking only water for 4 years. He had severe eye problems and behavioral problems ⁽⁵⁾. Vitamin A therapy helped his eyes and reduced behavioral problems. While this boy had almost no vitamin A in his diet, less severe vitamin A deficiencies may also occur in people with autism.

Some people may have problems getting vitamin A from their food or they may need extra vitamin A in order to be healthy. These people are described as having a metabolic disorder and vitamin A may help them to be healthy ^{(7, 8)}.

Dr. Megson is the doctor who has written the most about vitamin A and autism. She describes the use of vitamin A to treat children who are missing a specific gene (G-alpha protein defect) that normally helps the body use vitamin A. She believes that giving the patient more vitamin A can treat this genetic problem. While her theory is well described, it is, as yet, unproven ⁽³⁾.

Most scientists and doctors don’t understand how vitamin A supplementation might help most people with autism.

Does it work?

There have been very few studies published on the effects of vitamin A therapy on people with autism. One case report of two children has shown that vitamin A therapy can help people with autism ⁽³⁾. These two children were believed to have a G-alpha protein defect (see What is the theory behind it?). When treated with vitamin A therapy, they showed improvements in speech, eye contact, and vision.

Is it harmful?

Vitamin A may be harmful if someone takes too much (toxicity). Side-effects may vary and depend on what type of vitamin A is taken. For example, carotenoids found in foods are not toxic ^{(4, 9)}.

The recommended daily allowances (RDA) for vitamin A are: 1,000 IU for infants; 1,320 to 2,000 IU for children; and 700 to 1,300 IU for adults (depending on sex, age, and breast-feeding status) ^{(4, 9)}.

The upper limits (maximum daily dose) for vitamin A ^{(4, 9)} are: 2,000 IU for 0 to 3 years old; 3,000 IU for 4 to 8 years old; 5,610 IU for 9 to 13 years old; and 9,240 to 10,000 for adults.

Vitamin A in retinoid forms can lead to health problems when taken at doses above the recommended amount. The range between recommended dose and toxic dose is narrow for retinoid forms of vitamin A as compared to other vitamins.

Side effects of too much vitamin A include queasy stomach, yellowed skin (jaundice), moodiness, irritability, weight loss (anorexia), vomiting, blurry vision, headaches, hair loss, muscle and abdominal pain and weakness, drowsiness and altered mental status.

Check with your child’s pediatrician before starting treatment.

Cost

The cost of vitamin A supplements can vary and depends on the quality of the ingredients, the form and concentration of vitamin A, and the store where it is bought. A bottle of 100 gel capsules often range from $3 to $12.

Ask your child’s pediatrician which forms are best for your child.

Resources

Healing Thresholds has partnered with Webvitamins. They have a large selection of top quality vitamins and supplements.

Vitamin A can also be purchased in a drugstore. It can be included in a multivitamin supplement or it can be purchased individually. Supplements can also be found online, sometimes at a discount.

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References

1. Nagao, A. 2009. "Absorption and Function of Dietary Carotenoids." Forum Nutr. 61:55-63. Epub@2009 Apr 7:55-63.
2. Sommer, A. 2008. "Vitamin A Deficiency and Clinical Disease: An Historical Overview." J Nutr. 138(10):1835-1839.
3. Megson, M.N. 2000. "Is Autism a G-alpha Protein Defect Reversible with Natural Vitamin A?" Med Hypotheses 54(6):979-83.
4. National Institutes of Health. 2006. "Dietary Supplement Fact Sheet: Vitamin A and Carotenoids." Available at: URL: http://ods.od.nih.gov/factsheets/vitamina.asp.
5. Uyanik, O., et al. 2006. "Food Faddism Causing Vision Loss in an Autistic Child." Child Care Health Dev. 32(5):601-602.
6. Steinemann, T.L., and S.P. Christiansen. 1998. "Vitamin A Deficiency and Xerophthalmia in an Autistic Child." Arch Ophthalmol. 116(3):392-393.
7. Johnston, M.V. 2000. "Commentary: Potential Neurobiologic Mechanisms through which Metabolic Disorders Could Relate to Autism." J Autism Dev Disord. 30(5):471-473.
8. Page, T. 2000. "Metabolic Approaches to the Treatment of Autism Spectrum Disorders." J Autism Dev Disord. 30(5):463-469.
9. Institute of Medicine, Food and Nutrition Board. 2001. "Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc." Washington, DC: National Academy Press. Page 82.