Vitamin B12 is one of the most essential nutrients for brain health. It supports the production of key neurotransmitters, helps build and protect nerve fibres, and plays a central role in the biochemical processes that keep the brain functioning at its best. To dive deeper into those areas, read this article on How B12 Impacts ADHD Brains.
Low B12 levels are connected with ADHD — so if that’s you, you’re not alone. In this article, we’ll dive into the connections of ADHD with low B12, why people with ADHD have lower B12 levels, signs your B12 may be low, and how to increase your B12 levels naturally. For B12 supplementation and ADHD, read this article on Do B12 Supplements Help ADHD?
Low B12—ADHD Connection
A 2024 systematic review found that low B12 levels are connected with ADHD. However, that doesn’t necessarily mean it’s connected with worse ADHD 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.
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Why are B12 levels lower in children with ADHD?
There are many potential reasons why we consistently see lower B12 levels in children with ADHD:
- Diet: People with ADHD are more likely to prefer highly palatable, nutrient-poor foods and less likely to eat the eggs, meat, fish, and dairy that are the primary dietary sources of B12. Some people with ADHD are vegetarian or vegan, which can limit dietary – sources. Stimulants can also reduce appetite, which makes it difficult to get enough B12.
- Gut microbiome differences: A Swedish randomised controlled trial found that children with ADHD on psychostimulant medication had significantly lower abundance of the gut bacteria responsible for B12 synthesis, suggesting that kids with less manageable ADHD might have issues creating B12.
- Genetic metabolism differences: Gene variants affecting folate and B12 metabolism appear commonly in children with ADHD. These variants can impair the body’s ability to use B12 efficiently, even when dietary intake is adequate.
Signs That B12 May Be Low
Symptoms of B12 deficiency can overlap significantly with ADHD and can worsen existing ADHD symptoms if left unaddressed:
- Difficulty concentrating or increased mental fatigue
- Learning difficulties or declining academic performance
- Irritability or mood instability
- Memory problems
- Sleep disturbances
- Fatigue or low energy
Supporting B12 Naturally
The richest dietary sources of B12 are animal products: eggs, meat, fish, shellfish, dairy, and poultry. For people who eat a restricted diet or follow a plant-based diet, getting adequate B12 through food alone is very difficult, and supplementation may be necessary. A natural way to supplement is through eating nutritional yeast.
To dive deep into how to optimize B12 absorption, along with a longer list of B12 foods, read this article on How to Increase B12 Absorption.
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.
