Magnesium Glycinate Should Not Be Recommended for Children with Autism Spectrum Disorder
Magnesium supplementation (including magnesium glycinate) is not supported by evidence for treating core symptoms of autism spectrum disorder and should not be routinely recommended. The American Academy of Child and Adolescent Psychiatry (AACAP) guidelines explicitly state that oral vitamin B6 and magnesium have been "repeatedly shown not to work" in randomized controlled trials 1.
Evidence Against Magnesium Supplementation in ASD
Guideline Recommendations
The 2014 AACAP practice parameters classify magnesium (combined with vitamin B6) as an alternative/complementary treatment that lacks empirical support 1. The guidelines specifically note that:
- Randomized controlled evidence does not support the use of vitamin B6 and magnesium for treating ASD symptoms 1
- These treatments fall into the category where "the treatment has been repeatedly shown not to work" 1
- Clinicians should discuss these treatments with families while explaining their lack of proven benefit 1
Research Evidence Shows Mixed to Negative Results
The highest quality controlled trial found no beneficial effects:
- A 1997 double-blind, placebo-controlled study showed high-dose pyridoxine and magnesium was "ineffective in ameliorating autistic behaviors" using validated assessment scales 2
- The study found no clinically significant improvements on the Children's Psychiatric Rating Scale or Clinical Global Impression Scale 2
Importantly, adverse effects have been documented:
- Two children with ASD developed hyperactivity when administered pyridoxine-magnesium, with a "probable to possible association" on the Naranjo Adverse Drug Reaction Probability Scale 3
- This represents a clinically significant worsening of symptoms 3
Older Studies Are Methodologically Weak
While some older studies (1985,2006) suggested benefits 4, 5, these have not been replicated in higher-quality controlled trials. The 1997 controlled study directly contradicts these earlier findings 2.
When Pharmacotherapy IS Appropriate in ASD
The AACAP guidelines clearly state that pharmacotherapy should only be offered when there is a specific target symptom or comorbid condition 1. Evidence-based targets include:
- Irritability and aggression: FDA-approved medications (risperidone, aripiprazole) have proven efficacy 1
- Hyperactivity/inattention: Methylphenidate shows benefit in controlled trials 1
- Anxiety, depression, sleep disturbances: Treat as comorbid conditions 1
Clinical Approach
If families inquire about magnesium glycinate:
- Acknowledge their motivation to explore all treatment options 1
- Explain that controlled trials do not support its use for ASD symptoms 1, 2
- Discuss potential for adverse effects including hyperactivity 3
- Redirect toward evidence-based interventions: behavioral therapies, educational interventions, and pharmacotherapy for specific target symptoms when appropriate 1
Common pitfall to avoid: Do not dismiss family concerns, but clearly communicate that resources (financial and time) are better directed toward evidence-based treatments rather than supplements that have been shown ineffective in controlled trials 1.
The evidence hierarchy is clear: guideline-level recommendations based on randomized controlled trials demonstrate lack of efficacy, with documented potential for harm.