Autism Therapy: Vitamin B6 and magnesium

What is it?

Vitamin B6 (pyridoxine) is an essential vitamin that is necessary for more than 60 biological processes in a healthy human body. The body converts vitamin B6 into pyroxidal-5-phosphate (PLP), a compound that is used to release energy from carbohydrates and starches, and to break down proteins. PLP is also used in the production of important chemicals in the brain ⁽¹⁾.

Magnesium (Mg) is an essential mineral that is necessary for the health of every cell in the body, including the proper functioning of brain and muscle cells. While, magnesium deficiency is rare, some research suggests that children with autism may have too little magnesium ^{(2 3)}.

Some parents supplement a child's diet with a combination of vitamin B6 and magnesium as an alternative therapy for autism.

What's it like?

Vitamin B6 and magnesium supplements can be purchased online, or from almost any grocery, drug, or health-food store (see Resources).

Vitamin B6 is found in many foods; avocados, liver, nuts, chicken, fish, wheat germ, and bananas are good sources of the vitamin. Vitamin B6 is often included as one of many vitamins in a multivitamin supplement, but check with your child's pediatrician before starting a supplement. Vitamin B6 supplements can be taken every day, but may be difficult to give to children, since some children may find that vitamin B6 tastes bitter in tablet or powder form. Liquid B6 supplements are also available and may be better tasting ⁽⁴⁾. Doses of vitamin B6 in research studies varied from 0.6 mg/kg/day (about 10.8 mg/day for a 40-pound child) ^{(3 )}, to 30 mg/kg body weight/day (about 545 mg/day for a 40-pound child) ^{(5, 6)}.

By comparison, the U.S. recommended daily allowance (RDA) for vitamin B6 is 1.3 to 1.7 mg/day for adults, and 0.5 to 0.6 mg/day for children ages 1 to 8 years old ⁽⁷⁾.

Magnesium is found in many foods, but is especially plentiful in green vegetables, seeds, nuts, and whole grains. A supplement containing magnesium can be taken every day, but check with your child's pediatrician before starting a supplement. While it is not clear what the proper dose for children with autism should be, research reports used a dose in the range of 6 to15 mg/kg/day (or about 108 to 270 mg total daily for a 40-pound child) ^{(3, 8)}.

For comparison, the U.S. Daily Reference Intakes for magnesium is 320 to 420 mg/day for adults, and 80-130 mg/day for children ages 1 to 8 years old ⁽⁷⁾. Some parents supplement magnesium by giving their children Epsom salt (magnesium sulfate) baths. While magnesium can be absorbed through the skin, it is hard to say what dose of magnesium a child is getting from an Epsom salt bath.

If you choose vitamin B6 and magnesium as an alternative therapy, ask your child's pediatrician about the dose appropriate for your child. Vitamin B6 can cause upset stomach when not taken with a meal, so also ask a physician to provide a sample schedule for taking B6 and magnesium (see Is it Harmful?).

What is the theory behind it?

The enzyme that is used to break down vitamin B6 into PLP may not work as well in children with autism ^{(4, 9)}. PLP is needed for the production of dopamine, a brain chemical that is very important for many behaviors ⁽¹⁾. If children with autism are not producing enough PLP from the vitamin B6 they have in their diets, then supplementing with extra B6 may help boost the production of PLP to more normal levels ⁽⁹⁾.

Children with autism can have significantly lower levels of magnesium in hair and blood than non-autistic children ^{(2, 3, 10)}. There is evidence that magnesium supplementation can have a calming effect on some children with attention-deficit hyperactivity disorder (ADHD) ⁽¹¹⁾.

Aside from the necessity of magnesium for the overall physical health as well as the proper functioning of the brain, there is no specific theory about how magnesium deficiency could contribute to autism. The two supplements are often given together, as some researchers have reported that the side effects of vitamin B6 treatment are eliminated by magnesium ⁽¹²⁾. However, studies in which vitamin B6 was used alone did not report any adverse side effects ^{(8, 13)}.

Does it work?

There is some controversy surrounding the evidence for the effectiveness of vitamin B6 and magnesium in autism ⁽¹²⁾. Two small but well-controlled studies showed no effects, positive or negative, of combined vitamin B6 and magnesium therapy ^{(14, 15)}. One larger, but less well-controlled study showed positive and significant behavioral effects of combined vitamin B6 and magnesium, but not vitamin B6 or magnesium alone ⁽¹⁴⁾.

Additional studies showed that vitamin B6 and magnesium had significant positive effects on behavior in children with autism ^{(3, 8, 16, 17)}. There were, however, major problems with the designs of these studies. In particular, the researchers in these studies knew that the children were receiving supplements. Therefore, their ratings of the children's behavior could be biased. However, one of these studies did include another small, double-blind, portion suggesting that vitamin B6 and magnesium therapy can improve behavior in some children with autism ⁽¹⁶⁾.

The difference in outcomes of the various studies could be because vitamin B6 and magnesium results in positive behavioral effects for about half of those who try the therapy ⁽¹⁸⁾. Another explanation is that vitamin B6 and magnesium supplementation is not effective. The better-designed studies suggest that this may be the case, although these studies were so small, it is difficult to draw conclusions from them ^{(12, 18)}.

Is it harmful?

Vitamin B6 can cause nerve problems at high doses (in adults, over 2g/day) ⁽¹⁹⁾. However, studies of children with autism taking vitamin B6 and magnesium have reported no significant side effects ^{(4, 14)}. Furthermore, in children with epilepsy who had been taking high doses of vitamin B6 or PLP (900 mg for a 40-pound child) for six months, no significant side effects were reported ⁽¹³⁾.

Magnesium can be toxic at doses greater than 600 mg a day. However, studies using magnesium supplements at moderate doses (around 200 mg a day) have not reported significant side effects ^{(8, 11)}.

Check with your child's pediatrician before starting treatment.

Cost

A bottle of 100 multivitamin tablets containing B6 can cost anywhere from $10 to $40, and a bottle of 100 tablets of magnesium supplements at 250 mg per tablet can cost anywhere from $5 to $20. Prices depend on the store and the brand of the supplement.

Magnesium and vitamin B6 can come in several forms; 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 B6 and magnesium can be purchased online or in a drugstore. They can be included in a multivitamin supplement or they can be purchased individually. Supplements can also be found online, sometimes at a discount.

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References

1. Holman, P. 1995. "Pyridoxine - Vitamin B-6." Journal of Australian College of Nutritional & Environmental Medicine 14(1):5-16.
2. Strambi, M., et al. 2006. "Magnesium Profile in Autism." Biol.Trace Elem Res 109(2):97-104.
3. Mousain-Bosc, M., et al. 2006. "Improvement of Neurobehavioral Disorders in Children Supplemented with Magnesium-Vitamin B6. II. Pervasive Development Disorder-Autism." Magnes Res. 19(1):53-62.
4. Adams, J.B., and C. Holloway. 2004. "Pilot Study of a Moderate Dose Multivitamin/Mineral Supplement for Children with Autistic Spectrum Disorder." J Altern.Complement Med. 10(6):1033-1039.
5. Rimland, B., and S.M. Baker. 1996. "Brief Report: Alternative Approaches to the Development of Effective Treatments for Autism." J Autism Dev Disord. 26(2):237-241.
6. Hunsinger, D.M., et al. 2000. "Is There a Basis for Novel Pharmacotherapy of Autism?" Life Sci 67(14):1667-1682.
7. U.S.Department of Agriculture. 2009. "Food and Nutrition Information Center: Dietary Guidance." USDA National Agricultural Library.
8. Martineau, J., et al. 1985. "Vitamin B6, Magnesium, and Combined B6-Mg: Therapeutic Effects in Childhood Autism." Biol.Psychiatry 20(5):467-478.
9. Adams, J.B., et al. 2006. "Abnormally High Plasma Levels of Vitamin B6 in Children with Autism not Taking Supplements Compared to Controls not Taking Supplements." J Altern.Complement Med. 12(1):59-63.
10. Fido, A., et al. 2002. "Biological Correlates of Childhood Autism: Trace Elements." Trace Elem Electrolytes 19:205-208.
11. Starobrat-Hermelin, B., and T. Kozielec. 1997. "The Effects of Magnesium Physiological Supplementation on Hyperactivity in Children with Attention Deficit Hyperactivity Disorder (ADHD). Positive Response to Magnesium Oral Loading Test." Magnes.Res 10(2):149-156.
12. Nye, C., and A. Brice. 2005. "Combined Vitamin B6-Magnesium Treatment in Autism Spectrum Disorder." Cochrane.Database.Syst.Rev. (4):CD003497.
13. Wang, H.S., et al. 2005. "Pyridoxal Phosphate is Better than Pyridoxine for Controlling Idiopathic Intractable Epilepsy." Arch.Dis.Child 90(5):512-515.
14. Findling, R.L., et al. 1997. "High-Dose Pyridoxine and Magnesium Administration in Children with Autistic Disorder: an Absence of Salutary Effects in a Double-Blind, Placebo-Controlled Study." J Autism Dev Disord. 27(4):467-478.
15. Tolbert, L., et al. 1993. "Brief Report: Lack of Response in an Autistic Population to a Low Dose Clinical Trial of Pyridoxine Plus Magnesium." J Autism Dev Disord. 23(1):193-199.
16. Lelord, G., et al. 1981. "Effects of Pyridoxine and Magnesium on Autistic Symptoms-Initial Observations." J Autism Dev Disord. 11(2):219-230.
17. Rimland, B., et al. 1978. "The Effect of High Doses of Vitamin B6 on Autistic Children: A Double-Blind Crossover Study." Am J Psychiatry 135(4):472-475.
18. Pfeiffer, S.I., et al. 1995. "Efficacy of Vitamin B6 and Magnesium in the Treatment of Autism: A Methodology Review and Summary of Outcomes." J Autism Dev Disord. 25(5):481-493.
19. Schaumburg, H., et al. 1983. "Sensory Neuropathy from Pyridoxine Abuse. A New Megavitamin Syndrome." N.Engl.J Med. 309(8):445-448.