B12 and Folate play important role in a process that happens in every cell of the body called Methylation. Methylation helps the body make a lot of different chemicals such as vitamins, amino acids, brain signaling chemicals, hormones, red blood cells, antioxidants and genetic material. So as you can see it is important.
Essentially Methylation is like a massive game of "hot potato" happening in your body, where things called 'methyl groups' (CH3) are passed around to various molecules, including your DNA. This process is important in ADHD as it:
1. Balances neurotransmitters (dopamine and norepinephrine - both run low in ADHD)
2. Produces myelin (the insulation for your brain's wiring)
3. Controls gene expression related to attention and impulse control
Therefore disruptions in the methylation cycle can potentially contribute to ADHD symptoms.
Any discussion of B-12 and folate will involve homocysteine. Homocysteine is an amino acid that plays a crucial role in the body's methylation cycle. It is formed in the body as an intermediate product during the metabolism of methionine, another amino acid.
In a properly functioning cycle, homocysteine is converted back to methionine through a process that requires vitamin B12 and folate. (Vitamin B12 acts as a cofactor for the enzyme methionine synthase, which converts homocysteine back to methionine. Folate—in its active form, methyltetrahydrofolate—provides the methyl group for this conversion).
Put simply, picture the methylation cycle as a biochemical merry-go-round:
1. Methionine (an amino acid) converts to S-adenosylmethionine (SAM)
2. SAM donates its methyl group to various molecules (this is where the magic happens!)
3. After donating its methyl group, SAM becomes homocysteine
4. Here's where B12 and folate come in: they help convert homocysteine back to methionine, keeping the cycle going.
When this cycle is disrupted (maybe due to low B12 or folate), homocysteine can build up. This is where things can get tricky for our brains because homocysteine can cause damage to the brain in the long run leading to conditions like Parkinson's, dementia and Alzheimers.
A study published this year¹ found that children with ADHD had higher homocysteine levels and lower B12 levels compared to children without ADHD. This suggests that there might be a connection between B vitamin status and ADHD symptoms.
Another study, a systemic review², showed that children with ADHD have lower levels of B12 and B9 in their bodies compared to their neurotypical friends.
Supplementation of B12 and folate seems reasonable for ADHD children, but evidence specifically addressing this matter is very scarce. The benefits are likely small, but so are the risks of trialing both B12 and B9. Factors like individual metabolism, genetic variations, and overall diet can all influence how these vitamins affect ADHD symptoms and will differ from child to child in terms of what response, if any, is felt.
Another interesting study³ found that supplementing with vitamin B6 and magnesium improved ADHD symptoms in children. While this doesn't directly involve B12 or folate, it adds to the evidence that B vitamins play a role in ADHD management.
A Closer Look at B12 and Folate
Let's break down these vitamins a bit more:
- Vitamin B12 (Cobalamin): This powerhouse vitamin is crucial for brain function, nerve tissue health, and the production of red blood cells. It's like a master key that unlocks various biochemical processes in your body. Fun fact: B12 is the only vitamin that contains a metal ion (cobalt)!
- Folate (Vitamin B9): Folate is a term for a group of compounds, including folic acid (the synthetic form) and naturally occurring folates. It's essential for DNA synthesis, repair, and methylation. Think of folate as the construction worker of your cells, helping to build and maintain your genetic blueprint.
The MTHFR gene and Folate
This gene codes for an enzyme that helps the body process Folate. When the gene doesnt contain the correct instructions (called a polymorphism mutation), a working enzyme is not produced and the body is unable to process folate into L methylfolate which is what the body is able to use and put to work⁴. This mutation increases the risk that an individual will develop ADHD⁵. This is thought to be because the mutation upsets the amount of neurotransmitters produced, such as serotonin and dopamine, important brain chemicals in ADHD, which when out of whack, give us ADHD symptoms.
What type of B12 is best?
The ones to look out for in the store are Hydroxocobalamin, aka Hydroxo b12 , and Adenosylcobalamin or Adeno/Adenosyl B12. These are easier for your body to absorb compared to Cyanocobalamin, which is less easy for your body to absorb.
However, the best type of B12 is called Methylcobalamin. It is a great option and is thought to stay working in the body for longest and is also easy to absorb⁶ making it MVP.
Whichever type you choose, read the label on the front and back to figure out what type of B12 you are buying.
What type of B9 is best?
Folate is a generic term that describes the many different forms of Vitamin B9 such as folic acid, Folinic acid (5-formyl-tetrahydrofolic acid), Dihydrodfolate (DHF), tetrahydrofolate (THF), 5,10-methylenetetrahydrofolate (5, 10-MTHF) and 5-methyltetrahydrofolate (5-MTHF).
5-MTHF is considered ‘active’ and easy for the body to use. It is also known as L methylfolate and is particularly helpful in ADHD as it can cross the blood brain barrier.
L methylfolate runs low in those with ADHD⁷
How do we dose B12 and B9?
Dosages for B12
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 Board. These RDA values are based on meeting the nutrient requirements of 97 to 98% of ‘healthy individuals’ without the metabolic and nutritional complexities of ADHD. The Food and Nutrition Board acknowledges that the RDAs that they recommend are not intended for individuals with specific health conditions, like ADHD (Godbout Laake & Compart, 2013).
In addition, the RDAs are the amounts recommended from all sources, food and supplements. Children with ADHD may be getting a lot less B12 and B9 from food compared to their neurotypical friends, thanks to impulsive and unhealthy eating habits with a possible preference for processed and packaged snacks and meals, due to dopamine seeking behaviors. They are going to require higher doses of supplementation compared to their neurotypical friends.
I have provided the RDA values for B12 below for reference so that you can see the dosing recommendation for ‘healthy’ individuals and compare it to the dosing recommendations for ADHD that follow.
Recommended Dietary Allowances (RDAs) for B12⁸
Age (years) | Dose (mcg) |
1-3 | 0.9 |
4-8 | 1.2 |
9-13 | 1.8 |
14-18 | 2.4 |
19+ | 2.4 |
The ADHD and Autism Nutritional Supplement handbook (Godbout Laake & Compart, 2013) suggests dosages in the table below for B12 specifically for Methylcobalamin. Again these doses are much higher than what you see in the RDA table above highlighting the differing daily requirements of children with ADHD compared to neurotypical children.
B12 dosing recommended for ADHD by Godbout Laake & Compart, 2013
Age (years) | Dose (mcg) | Total daily dose from all sources (mcg) |
6-10 | 100-500 | 500 |
11+ | 500-1000 | 1000 |
So what does this mean for B12 dosing?
So it appears that B12 is something where the dose can be increased slowly beyond what you see in the RDA table above as no Tolerable Upper Limits exist given how safe it is. The Tolerable Upper Limit is the maximum amount of a nutrient that can be taken every day without causing harm to the body. So, even at large doses, vitamin B12 is generally considered to be safe because the body does not store excess amounts because you pee it out. Research supports that high doses appear to be safe⁹. The European Food Safety finds that there are “No clearly defined adverse effects” for B-12 supplementation¹⁰.
Looking specifically at the children’s brand multi vitamins on the market, I am seeing dosages anywhere from 0.9 mcg all the way to 100mcg per dose showing you the wide range available and how different the dosages are between brands.
How to start B12 dosing
When starting your child on B12 I would start with the half dose of whatever is the lowest dose of the Methylcobalamin, or your chosen form of B12, that you are using. Do this for a couple of weeks before going up to the full dose in the Godbout Laake & Compart table above, and monitor for any side effects like headaches, nausea or vomiting. Using a liquid form is going to be best for this as you only draw up the syringe what you need.
For Methlycobalamin I recommend:
For 6-10 year old the dosing is 500 mcg so use 0.5ml of the the liquid form of Pure Encapsulations B12. A full 1ml is 1000mcg, so half of this will give the 500 mcg needed
For 11+ year old the most convenient way to get 1000mcg is going to be to use Pure Encapsulations Methylcobalamin capsules. But if capsules are an issue use the liquid form where 1ml gives us 1000 mcg.
As always discuss supplement dosing with your child’s healthcare provider before starting and when increasing the dose so they can guide and monitor your child.
Toxicity and side effects
B12 is considered relatively safe because the body does not store high amounts meaning that it doesn't build up to high enough levels to cause toxic problems.
But high doses may cause these side effects:
Headache
Nausea and vomiting
Diarrhea
Fatigue or weakness
Tingling sensation in hands and feet
Medications your child may be taking that B12 interacts with:
Stomach acid blockers like omeprazole (Prilosec) lansoprazole (Prevacid)
Histamine 2-receptor antagonists, such as cimetidine (Tagamet) and ranitidine (Zantac). These two medications will decrease the amount of B12 that the stomach is able to absorb.
Metformin. This is used to treat high blood sugar and reduces the amount of B12 that the body is able to absorb.
People who should avoid B12: People with allergies to B12 or Cobalt.
Now onto dosing for Folate B9
RDA and Upper Limit dosing for Folate¹¹
Age (years) | RDA Dose (mcg) | Upper Limits (mcg) |
4-8 | 200 | 400 |
9-13 | 300 | 600 |
14-18 | 400 | 800 |
19+ | 400 | 1000 |
Do not take levels higher than that in the chart above without first consulting with your child's health care provider so that they are able to adequately advise and monitor your child during supplementation.
Giving the body more B9 than it can process can weaken the immune system so best to stick to the suggested ranges above.
If you have the Godbout Laake book you will notice that they reference and recommend folinic acid as the best form of B9 for ADHD. The issue here I have is that it is difficult to find on the market, and Pure Encapsulations, a brand that I heavily use based on its purity and quality, does not carry a folinic acid. So for ADHD, I use L methylfolate based on its availability to consumers and ability to cross into the brain and exert its effects.
How to start B9 dosing
So it appears that B9 can be dosed anywhere between the RDA and Upper Limit values in the table above for any given age range.
For all ages I recommend Folate400 by Pure Encapsulations.
So for 4-8 years: Take one capsule of Folate400 by Pure Encapsulations for 400 mcg of L methylfolate.
9-13 years: Take one capsule of Folate400 by Pure Encapsulations for 400 mcg of L methylfolate
14-18 years: Take 1-2 capsules of Folate400 by Pure Encapsulations for 400-800 mcg of L methylfolate.
19+ years: Take 2 capsules of Folate400 by Pure Encapsulations for 800 mcg L methylfolate.
Capsules can be opened and sprinkled into food (applesauce, yogurt).
If you are wanting to go higher than the suggesting dosing above, loop in your child's healthcare provider so that they can guide you and keep your child safe and healthy. Before starting any supplementation, regardless of dose, let your child's healthcare provider know so that they can check for any interactions the supplements may have with medications that they are taking, and for any health conditions which may make taking supplementation dangerous for your child.
Medications your child may be taking that folate interacts with:
Sulfasalazine. This treats ulcerative colitis and can decrease the amount of Folate and the body.
Methotrexate. this is used to treat cancer and autoimmune disease and reduces the amount of Folate in the body.
Antiseizure medications/mood stabilizers. Includes phenytoin, carbamazepine and valproate. Folate may decrease the amounts of these medications in the body making them less effective, and putting your child at risk of seizure or breakthrough mood issues (based on what they take the anti seizure/mood stabilizing medications for)
Side effects of Folate to look out for: Feeling sick (nausea), loss of appetite, tummy bloating.
Toxicity has not been reported however if folate supplementation is something that you are interested in, first talk to your doctor about doing a blood test for B12 to get a baseline for this nutrient. This is because if your child has low B12 and you supplement with folate at home, it might mean that the healthcare provider may miss the low B12 because the folate will ‘mask’ the B12 deficiency. This means the B12 deficiency will go unrecognized and untreated and cause nerve damage if not caught in time.
We are unsure as to whether high doses of B9 are toxic at this time¹².
Who shouldn't take Folate without first talking to their health care provider:
People with cancer
People on dialysis
People with a heart stent
People with low B12 levels
Natural sources of B12 and Folate in food
In an ideal world, we would not be supplementing and children would be getting all of their nutrition from food. However, this is somewhat unrealistic given our demanding Western life styles, but if you would like to incorporate B12 adn B9 naturally in the diet when possible, here is a list of food sources to help support healthy eating choices at home.
B12
Animal products (meat, fish, eggs, dairy)
Fortified plant-based milk and cereals
Nutritional yeast (a favorite among vegans!)
B9
Leafy greens (spinach, kale, collard greens)
Legumes (lentils, beans, peas)
Citrus fruits
Avocado
Fortified grains
Summary
While B12 and folate aren't magic pills for ADHD, they play important roles in brain health and function. The methylation cycle they support is crucial for neurotransmitter balance, myelin production, and gene expression – all of which can impact ADHD symptoms.
If you're considering supplementation, it's always best to chat with your healthcare provider first. They can help you determine the right dosage and whether it's appropriate for your specific situation. And remember, a balanced diet rich in B vitamins is a great place to start!
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.
Godbout Laake, D. & Compart, P. J. MD (2013) The ADHD and Autism Nutritional Supplement Handbook. Fair Winds Press.
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