Vitamin B12 (B12) is a water-soluble vitamin with key role in facilitating normal functioning of the brain, nervous system, and formation of blood cells. It is involves in DNA synthesis and regulation, and also fatty acid synthesis and energy production.
There are several forms of vitamin B12 – cyanocobalamin is the synthetic form, and methylcobalamin and adenosylcobalamin are the physiological or active form. Cyanocobalamin does not occur in nature. It is commonly found in supplements due to its stability and cheaper cost of manufacturing. Theoretically, cyanocobalamine is readily converted to the active forms, methylcobalamine and/or adenosylcobalamin in the body.
VITAMIN B12 AND ADHD
B12 helps with ADHD symptoms through it’s involvement in many of the brain functions, especially in the production and maintenance of the myelin sheath (the protective coating on nerve cells), essential fatty acid metabolism and energy production.
B12 is involved in the synthesis and integrity of the myelin sheath that covers all nerve cells. Think of the plastic casing on electrical wires. These myelin sheath serve the same purpose. Vitamin B12 is the cofactor for the enzymes, L-methylmalonyl-CoA mutase and methionine synthase.
L-methylmalonyl-CoA mutase needs adenosylcobalamin to convert L-methylmalonyl-CoA (MMA) to succinyl-CoA. If this reaction is not working well, too much MMA will result. Too much MMA will make the myelin sheath unstable or not effective in doing its job. The extra MMA may also be added in place of fatty acids, such as omega-3 fatty acid, into myelin sheath. This will result in fragile myelin sheath that is not able to support normal brain functions. The precise mechanism(s) are not fully understood at this time.
B12 also affects in the myelin formation process in another way. Methylcobalamin is a cofactor of methionine synthase, which catalyzes the conversion of homocysteine to methionine. Our body can also obtain methionine through diet. Our body needs methionine to make S-adenosyl-methionine (SAMe), which is needed for methylation of myelin sheath phospholipids. Methylation is the transfer of the “methyl” group. Methycobalamin provides the methyl group for the transfer. That is how methylcobalamin is involved here. Although our body does not need B12 to make SAMe, methionine synthase helps to provide additional methionine to boost SAMe production. SAMe is also involved in the production of certain neurotransmitters and catecholamines, which help with mood.
Vitamin B12 deficiency is rare because the liver can store several years’ worth of B12. However, deficiency does happen. Certain medical conditions and/or medication may interfere with absorption or increased it’s metabolism in the body. The total amount of B12 stored in body is bout 2–5 mg in adults. Around 50% of this is stored in the liver.
SYMPTOMS OF VITAMIN B12 DEFICIENCY
Deficiency is usually the result of poor intestinal absorption due to GI surgeries and/or GI disorders, or inadequate dietary intake, such as vegetarian or vegan diet, which restrict animal products. Occasionally, certain medication may increase its metabolism in the body.
Signs and symptoms include weakness or fatigue, light-headedness, rapid heartbeat and breathing, pale skin, sore tongue, easy bruising or bleeding such as bleeding gums, stomachache, weight loss, and diarrhea or constipation.
B12 deficiency may result in megaloblastic anemia, which is due to an defective red blood cell production. The resultant red blood cells are larger than normal, which make is difficult to transport nutrients due to size constraint.
Other signs and symptoms are tingling or numbness in fingers and toes, difficulty walking, mood changes or depression, memory loss, disorientation, and dementia, which are results of nerves damages from vitamin B12 deficiency.
Neither plants nor animals can produce B12. Only bacteria have the enzymes required for its synthesis. Animals are good sources of B12 is because of the bacteria living in the intestines, which makes the vitamin.
Vitamin B12 is found in any foods that come from animals, such as fish and shellfish, meat (especially liver, where the vitamin is stored), poultry, eggs, dairy products. The body absorbs B12 from animal sources better. Plant foods are not considered to be reliable sources of B12.
Vegans, people who do not eat any animal products including eggs and dairy, are more likely to develop B12 deficiency because of their restrictive diets. Ovo-lacto-vegetarians usually consume enough B12 through eggs and dairy products. Vegans obtain their B12 from dietary supplements and/or fortified foods, such as fortified breakfast cereals, fortified soy products, fortified energy bars, and Brewer’s yeast.
Cyanocobalamin is the most common form of B12 found in supplements. It contains about 2% of cyanide or 20 micrograms cyanide in a 1 mg cyanocobalamin tab. This amount may seem minute. However, children with ADHD, as you have read so far, have an inefficient detoxification system. Even minute amount of cyanide may accumulate over time, causing neural damages.
One of the functions of B12 is methyl donation. Supplementation with cyanocobalamin would not serve this purpose. In fact it would need donation of methyl group in the body to be converted to the active form.
Sublingual and spray methylcobalamin are supposedly much easier to absorb because these routes bypass the intestines, which can be an issue for people with GI problems. Besides methylcobalamin is the active form, which means the body can put it to use right away without any further conversion. Besides, children with ADHD just seem to have very different metabolic requirements.
Methylcobalamin supplements are usually more expensive and available mainly in health food stores. Despite the cost and probably a little extra drive for some, it is still a better choice not only because it is the active, but it is also a “cleaner” form. The methylcobalamin supplement you find in health food stores usually are free of additives, preservatives, artificial colorings, artificial sweeteners, etc. So you are definitely paying for quality for your money.
General recommendation of B12 is between 0.4 to 2.4 mcg (micro-grams) daily depending on age. Generally, for the purpose of treating ADHD, you may start with 1,000 mcg. Toxicity is rare since Vitamin B12 is water-soluble, which means our body can easily get rid of the extra.
Couple years ago, I developed tingling sensation on my hands and feet after some medication adjustment. After doing some research, I discovered that the tingling is related to B vitamins deficiency. I started with B-complex, then later added B12. The tingling disappeared, but I was not falling asleep at night. Then I realized it’s the high dose of B12 I was taking at night. That’s what keeping me up at night. And that’s also when I realized the power of B12 vitamin. It does give you an energy boost, but without the hyper feeling of caffeine.
Now I take a 2,500mcg B12 vitamin tablet in the morning. While I started taking the B12 vitamin, I also noticed that I am less irritable and anxious.
My daughter takes a 1,000mcg tablet daily before school to help her focus. She also takes 1.5mg melatonin at night to help with her sleep. Interestingly, after taking the melatonin, she told me that her brain feels clearer and she can organize her thoughts better.