Do B12 Supplements Help ADHD?

If you’ve read about the link between vitamin B12 and ADHD, you might be wondering: Should I take a B12 supplement?

The short version: B12 supplementation may help people with ADHD who are genuinely deficient in B12, but it’s likely that it will help mainly with overall cognitive functioning rather than ADHD symptoms directly. If you aren’t deficient in B12, it likely won’t have an effect at all.

What the Research Shows

Multiple studies have confirmed that children with ADHD tend to have lower serum levels of B12 and folate than healthy peers. A 2024 systematic review found significantly lower vitamin B12 levels in ADHD kids.

But lower levels don’t automatically mean supplementation will improve symptoms. In fact, this 2020 study found no connection with ADHD symptom severity and B12 deficiency. However, B12 is important for brain health, and being deficient in it could have negative effects on cognition. For instance:

In one study, B12 levels correlated positively with IQ scores in children with ADHD, meaning children with higher B12 tended to perform better cognitively.
Another study found that B12 deficiency affected social functioning in kids with ADHD.

Will B12 Supplementation Help ADHD?

Truthfully, there is no research on B12 supplementation and ADHD. We do have adjacent research, however.

The most promising research is with broad-spectrum multinutrients and ADHD: high doses of multiple nutrients working together. The one studied with ADHD is Hardy Nutritionals. You can learn about the studies with ADHD and Daily Essential Nutrients here. As a disclaimer, I do work with them on science communication, and I personally use the supplement myself due to the research and the benefits I’ve experienced. You can listen to my podcast episode on it here. They seem to work the best with people experiencing emotional dysregulation and inattentive ADHD.

Broad vitamin B supplementation might help, especially if you are also autistic. A 2025 meta-analysis of 22 randomised controlled trials examined the effects of vitamin interventions across both ADHD and autism. It found that vitamin B supplementation had a significant therapeutic effect on autism spectrum disorder.

If you have emotional dysregulation, such as a history of depression or anxiety, vitamin B12 may be a supplement to look into after testing for insufficiency. It’s possible to not be deficient in vitamin B12 and still benefit from it based on genetics, metabolism, and your gut microbiome.

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Who is Most Likely to Benefit?

Based on the available research, B12 supplementation is most worth considering if you or your child:

Has been tested and found to have low serum B12 or folate
Eats a restricted diet or follows a plant-based or vegetarian diet
Has learning difficulties (cognitive or social) or autism alongside ADHD
Experiences anxiety, depression, or other mood dysregulation
Has a known MTHFR gene polymorphism or family history of B12 deficiency

What B12 Supplement Do I Choose?

Not all B12 supplements are the same. The main forms available are:

Cyanocobalamin: The most common and least expensive form. It needs to be converted in the body to its active forms. Generally effective for most people.

Methylcobalamin: The active, methylated form of B12 that the body can use directly. This is often recommended for children with MTHFR variants or anyone who struggles to convert standard B12 effectively. It also directly supports the methylation pathway central to neurotransmitter production. However, this should be monitored by a physician as negative effects can arise.

Hydroxocobalamin A natural form found in food, often used in injections. It has a longer half-life than cyanocobalamin and is well-absorbed. Be wary of general wellness places giving this and opt for a physician’s prescription.

Final Thoughts

B12 supplementation isn’t a fix for ADHD, but for people who are genuinely low in B12, correcting that deficiency could logically support their attention, learning, and overall brain function.

The most responsible approach is to test first, then supplement if needed under the guidance of a healthcare provider.

This article summarizes the research from the aforementioned studies and the author’s knowledge. It is for educational purposes only. Nothing in this article constitutes medical advice.

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