According to The Linus Pauling Institute at Oregon State University, it is thought that just over half of all Americans do not meet their nutritional requirements for magnesium¹ whereas WHO suggests that approximately 75% of Americans do not meet the recommended daily intake of Magnesium.
In Autism, Magnesium is is thought to run low. When magnesium is not high enough in the brain it may impact the brain's ability to make what it needs. Magnesium is important because it increases the amount of special brain chemicals called Serotonin and GABA.
Serotonin makes us feel good. It helps control mood, sleep, learning, memory and behavior. In Autism there is thought to be not enough serotonin in the brain leading to problems with mood and behavior.
Melatonin is out brain's sleep chemical. It is made from serotonin using magnesium. Therefore if serotonin is low (because magnesium is low), then then brain will struggle to make melatonin, so sleep will not be great.
GABA is known for its calming properties. It makes us feel relaxed. In Autism there is thought to be an imbalance of GABA causing symptoms like impaired social skills, repetitive and restricted behaviors, and difficulty with thinking and learning. Magnesium works by rebalancing GABA in the brain to help lessen these symptoms.
Potential benefits of Magnesium supplementation in Autism:
Better alertness
Better social interactions
Better communication
Fewer emotional meltdowns
Less self harming
Better sleep
Which type of magnesium is best?
There are many different types of magnesium supplements on the market, such as magnesium oxide, magnesium citrate, and magnesium glycinate. Each contains magnesium bound to another molecule, and those molecules can be large. So 100mg of a magnesium salt may contain far fewer milligrams of actual magnesium.
Magnesium Compound | Percent magnesium by weight |
Oxide | 61 |
Threonate | 7 |
Citrate | 11 |
Glycinate | 14 |
But different forms of magnesium vary significantly in how well the body can absorb them. For example the chloride and citrate salts are absorbed about three times as well as magnesium oxide³ ⁴. They also vary in how likely they are to cause digestive issues like diarrhea, which is why magnesium glycinate works well in children⁵.
Best forms of Magnesium for ADHD: glycinate and threonate
Magnesium glycinate and threonate are particularly beneficial for children with Autism because they can more easily cross the blood-brain barrier and help regulate brain function. Unlike some other forms, it has few gastrointestinal side effects, making it ideal for children who may be prone to digestive discomfort.
Recommended Magnesium dosages
A word on the Recommended Daily Allowances (RDAs) numbers. These guidelines were established by The Institute of Medicine of the National Academies as well as the Food and Nutrition Boards. These RDA values are based on meeting the nutrient requirements of 97 to 98% of ‘healthy individuals’ without the metabolic and nutritional complexities of ASD leading to malnutrition. The Food and Nutrition Board acknowledges that the RDAs that they recommend are not intended for individuals with specific health conditions, like ASD¹.
In addition, the RDAs are the amounts recommended from all sources, food and supplements. Children with Autism may be getting a lot less Magnesium from food compared to their neurotypical friends.
With that in mind, children with ASD are going to require higher doses of supplementation compared to their neurotypical friends as they are likely not getting enough Magnesium from food due to being picky eaters.
I have provided the RDA values below for reference so you get an idea of what Magnesium doses typically run at.
Recommended Dietary Allowance (RDAs)²
Age | Dose (mg) |
1-3 years | 80 |
4-8 years | 130 |
9-13 years | 240 |
14-18 years | 360-410 |
19+ years | 310-420 |
As you can see, doses run into the hundreds, so that will be our baseline of what the lower end of dosing could look like for children with ASD, where you could start when first introducing it into their diet.
In their book, The ADHD and Autism Nutritional Supplement Handbook (2013), authors D. G. Laake and P. J. Compart MD, provide their recommendations (in the table below) for Magnesium daily dosing for children with Autism, which are higher than the RDA numbers above.
The numbers in the table below are from their book (referenced at the end of this post) could therefore serve as the maximum dosages you should give per day for the age groups listed.
Age (years) | Dose (mg) | Frequency | Total daily dose from all sources (mg) |
2 to 5 | 100 | 1 or 2 times per day | 200 |
6 to 10 | 100 | 2 or 3 times per day | 300 |
11 and above | 100 - 150 | 2 or 3 time per day | 450 |
Laake and Compart (2013) page 207
Magnesium dosing tip:
Whichever magnesium supplement you choose, start with a low dose and increase slowly to minimize side effects like diarrhea. For example, if the recommended dose is two capsules per day, start with one in the evening, and monitor your child’s tolerance before increasing the dose. For liquid formulations, use a 1ml syringe to start with a small amount (e.g. 0.5 ml) and gradually increase as needed.
MAGNESIUM DOSING GUIDE
Magceutics brand Magnesium Threonate is available in 1000 mg capsules, but only 7% of that is absorbable magnesium, meaning each capsule provides about 72 mg of magnesium. So if you are trying to provide 200mg of magnesium use 2 capsules to give 144mg. I do not recommend dosing higher than the 200mg shown in the table above so do not advise taking 3 capsules as this puts us at 216mg for this young age group. For 300mg use 4 capsules to give 280mg, and for 450 mg for older children, use 6 capsules for 420mg.
The capsules can be opened and sprinkled into a small amount of apple sauce, yogurt, etc for dessert 30 minutes before bed time. I have tried it straight out of the capsule, it's gritty with a slightly acidic taste, so making it more palpable by mixing it well with something tasty should help.
And again remember to build up to the amounts shown in the table above over weeks. If 6 capsules is your goal because you have a teenager, dont start with 6 capsules on day one. Start with one capsule for a few days, then two for a few days, then three etc, all the while looking out for any tummy upset or other side effects. If you are sticking purely with Magnesium threonate, a 120 capsule container may last you anywhere from 20-40 days depending on dosing, so approx $30/month (or $0.25 capsule).
Some formulations, such as Kiddo Calm gummies by Magtein, contain even less magnesium (24 mg of magnesium per gummy). So gummies are going to be an option for younger children if you wanting to build up very slowly and introduce it into their system conservatively, before switching to the capsules form which can be opened and sprinkled onto food (otherwise you are going to need 4-8 or more gummies to even hit the recommended dose of 100-200mg daily, which gets expensive as there are only 90 gummies in a container).
If you are going to opt for Pure Encapsulations brand, they have a magnesium glycinate liquid which can be handy for children who cannot handle capsules. The liquid is 165mg per 10ml. So doing some math, thats 16.5mg per 1ml and therefore 12.12ml would give us 200 mg and so on. The bottle is 480ml, so at the lower dosing range (200mg/day) it would last just under 40 days and at the higher dosage range (450mg) it would only last 18 days, at $46. So not terribly economical but an option when capsules are just not going to work for a younger child.
Pure Encapsulations brand Magnesium glycinate capsules contain 120mg magnesium per capsule compared with 72mg for magnesium threonate. Therefore they have just under double the amount of magnesium compared to threnoate. A bottle of 180 capsules is $45 (or $0.25 per capsule) so the same so the same per unit cost as threnoate, but you are getting more bang for your buck with each capsule.
Here is where I recommend combining glycinate with threonate to make the dosages work: For a total 200mg magnesium daily, the child would take 1 capsule of glycinate at 120mg and 1 capsule of theronate to give 190mg of magnesium total. Using 2 capsules of glycinate gives us 240mg, which is higher than the dose of 200mg for children ages 2-5. We don't go over 200mg per day for this young age group, and the range as listed in the table above is 100mg once or twice per day, so if you are shooting for once per day then just take 1 capsule of glycinate instead to give 120mg.
For children 6-10, the total daily amount in the table above is 300mg maximum (or 100mg taken 2-3 times per day). Here you could take 2 capsules of glycinate to total 240mg if you are shooting for somewhere between 200-300mg, or if you want to hit 300mg/day, then use 2 capsules of glycinate to total 240mg and add 1 capsule of threonate to give 310mg. For the highest dose range of 450mg for older children, take 3 capsules of glycinate to total 360mg and add 1 capsule of threnoate to give a grand total of 430mg, just short of the max dose of 450mg. If you are aiming for lower just take 3 capsules of glyincate to give 360mg instead which would still be appropriate for anyone 11 years and older, given the range here is 200mg at the lower range (100mg twice daily, to 450mg at the upper range (150mg three times daily). See table above. The handy cheat sheet associated with this post (click the picture above) will have a table with example dosing strategies using the compounds above.
Loop in your child's healthcare provider when considering the Magnesium supplementation so they can keep an eye on your child. Let them know if your child is experiencing any side effects, like those listed below.
Side effects to look out for: diarrhea, tummy cramping, nausea.
Toxicity: Magnesium levels in the body are controlled both by the gut (controlling how much is absorbed) and by the kidneys (controlling how much is peed out).
Magnesium is a relatively safe supplement as long as there are no kidney issues. In children with kidney problems the body cannot remove excess Magnesium so this could cause it build up to levels high enough to cause toxicity issues.
Signs of toxicity could show up as low blood pressure, dizziness, nausea, vomiting, facial flushing, inability to pee, painful blockage of the intestine, depression, low energy, muscle weakness, difficulty breathing, irregular heartbeat, heart attack and in very rare cases, death.
Medications your child may be taking that Magnesium interacts with²:
Bisphosphonates such as Fosamax (used to treat brittle bones). Magnesium can decrease the levels of this medicine in the blood making it less effective.
Antibiotics should be taken at least 2 hours before or 4–6 hours after Magnesium
Diuretics such as furosemide (Lasix) and bumetanide (Bumex), hydrochlorothiazide (Aquazide H) and ethacrynic acid (Edecrin), can cause the body to lose Magnesium in urine.
Long term use (more than a year) of Proton Pump Inhibitor (PPI) drugs, such as esomeprazole magnesium (Nexium) and lansoprazole (Prevacid), can cause low levels of Magnesium in the body. If taking PPIs ask your provider to check Magnesium levels throughout the year to make sure levels don't get too low.
People who should not take Magnesium without first talking to healthcare provider:
People with diabetes, intestinal disease, heart disease or kidney disease.
In the PDF here that I have attached, I have provided a Cheat Sheet for Moms with a summary of Magnesium’s characteristics discussed above, as well as a ‘cut the dotted line’ section for when it comes time to shop for Magnesium with steps and recommendations to keep in mind when purchasing including checking for third party testing to ensure that what you are buying is high quality.
Sign up to the Mommies In Mind 'Magnesium for Autism' workshop here to receive information about the February 2025 Magnesium for ASD workshop that I will be running. You will learn about supplementation, nutrition and diet to naturally support your child's magnesium levels.
Exact date TBD, will be emailed out in the coming weeks once you join the mailing list.
This site is for general informational purposes only and does not constitute the giving of medical advice. The contents do not constitute the practice of medicine, nursing, or other professional health care services. No provider–patient relationship is formed. Please consult with your child's healthcare provider when considering supplementation for children.
¹ Godbout Laake, D. & Compart, P. J. MD (2013) The ADHD and Autism Nutritional Supplement Handbook. Fair Winds Press. To purchase on Amazon click here.
³ Magnesium bioavailability from magnesium citrate and
magnesium oxide; J S Lindberga, M M Zobitza, J R Poindextera, and C Y Pak; figure four.
⁴ Bioavailability of US commercial magnesium preparations; M Firoz, M Graber; table two.
⁵ Bioavailability and pharmacokinetics of magnesium after administration of magnesium salts to humans; V V Ranade, J C Somberg; table one.