Vitamin B12 is important for energy, sleep, and your nervous system. In fact, vitamin B12 has so many virtues that I can’t wait to get to all the good stuff—the stuff that will really help people suffering from autoimmune conditions and serious health problems.
But first, a brief history lesson: The complete molecular structure for B12 wasn’t discovered until the 1960s. Way back in the 1930s, scientists knew that a substance could help people with pernicious anemia. Pernicious anemia causes damage to red blood cells and occurs when the body cannot properly absorb vitamin B12 from the gastrointestinal tract. This can result from poor gut health, from taking drug muggers, from having certain infections, or from a lack of intestinal flora (probiotics). People who have pernicious anemia feel tired, short of breath, confused, and off balance. To this day, vitamin B12 is still recommended for this purpose, and what’s so lovely is that many forms of B12 are available over the counter.
Vitamin B12 is water soluble and naturally present in some foods. It’s added to other foods. It’s available as a dietary supplement as well as a prescription medication given by intramuscular injection. No matter what the form, vitamin B12 contains the mineral cobalt, so any naturally occurring compounds with vitamin B12 activity are collectively called cobalamins. Methylcobalamin and adenosylcobalamin are the two primary active forms of natural vitamin B12. There is a synthetic version called cyanocobalamin that is used widely in foods and dietary supplements sold in health food stores. Cyanocobalamin has to be converted by the body to methylcobalamin before it can be utilized.
One of the most intriguing facts about B12 is that plants and animals can’t manufacture it on their own. Most vitamins are made by plants or animals, but only microorganisms—yeasts, molds, algae, and bacteria—can make B12. That’s important for humans because our digestive tracts contain friendly yeast and bacteria that manufacture this vital nutrient. For that reason, true deficiency is rare, but a deficiency based on having a poor camp of healthy microorganisms in the gut is quite common. In any case, you seriously need to be getting sufficient vitamin B12 for a number of reasons. For one thing, it helps you make red blood cells, and you need those for your very survival. A good store of red blood cells helps you create energy. Plus, red blood cells make up your blood!
One really cool thing about B12 (specifically, methylcobalamin) is that it provokes faster release of the sleep hormone melatonin, so you can get to sleep easier. It also happens to sensitize you to waking up earlier by causing the melatonin to retreat as soon as light shines into your room. So this is a good vitamin if you have sleep problems, although it may not work for everyone. Melatonin regulates sleep, and many older people who run out of B12 have trouble sleeping. You could be sleeping poorly because you are short on B12. If you take a drug mugger for B12, you could end up suffering with insomnia because, again, B12 provokes the release of your melatonin sleep hormone.
To treat insomnia, doctors generally prescribe conventional (and usually addictive) sleeping pills. Before you say yes to them, it’s worth giving a vitamin B12 supplement a try and adding in a little melatonin as well. (See Chapter 13 on melatonin on page 175 for more information about supplementing with this hormone.) I’m so happy to share that secret with you! You’ll likely get your doctor’s blessing on this approach. Studies have even shown that B12 supplementation not only helps people with sleep disorders get to sleep, but also improves the quality of their sleep and allows them to wake up feeling more refreshed.
Now the good stuff that I promised you at the beginning of the chapter. I’m going to focus on autoimmune conditions. If you have any sort of pins-and-needles sensations, numbness, nerve pain, or neuralgia (including trigeminal neuralgia), I want you to pay especially close attention right now.
If you have a history of autoimmune disease, rheumatoid arthritis, diabetic neuropathy, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease), or chronic neuralgia, then getting enough vitamin B12 is crucial for you, particularly methylcobalamin. These conditions are so hard to treat and so disabling that I’m delighted to tell you about this secret little B vitamin that I believe can help you.
Let’s focus on multiple sclerosis first. Some physicians realize that stress, nutritional deficiency, and exposure to solvents, pesticides, mercury, and other heavy metals play a role in MS and neurological disabilities. In people who have MS, the thin coating around the nerve fibers, known as the myelin sheath, starts to unravel and deteriorate. This process, called demyelination, strips away the protection the nerve fibers need and worsens over time. Understandably, the nerves become extremely sensitive. Imagine an electrical wire that has lost its insulation and outer coating. This is why people with demyelination disorders have chronic pain, numbness, tingling, burning, muscle cramps, and other weird sensations.
There are many theories about why the myelin breaks down. One possible reason that I believe is worth paying attention to is wheat protein (gluten) allergy, the autoimmune version of the disease called celiac disease. I think people with MS should stay away from gluten just as a safety measure. That means no more pizza, bagels, and a bunch of other goodies unless they are baked with gluten-free flours. It’s worth paying that price, in my opinion. It’s not that hard to go gluten free, and I’ve posted some information on my Web site, www.DearPharmacist.com, to help you. Studies show that when people with MS go on gluten-free diets, they often improve. I found an article published in Neurologia in 2009 that discussed remission in an MS patient who went on a gluten-free diet. While studies conflict, there are many experts who connect autoimmune disorders to gluten allergy.
Anyway, if your myelin sheath deteriorates, you start to feel pain, tingling, numbness, burning sensations, and so on. You may even be diagnosed with MS or another serious neurodegenerative condition. B12 can help you repair it.
That’s a hefty statement if you are one of those people who happen to suffer the painful consequences of myelin degeneration, so I am going to elaborate. I will refer to both methylcobalamin and methyl B12, which are the same thing, because you see it referred to both ways if you search studies in the literature. You can skip the science if you want to. I’m including it so that you know just how important B12 is if you have MS. Bear with me here.
The subject of myelin sheath degeneration could fill a book, and by no means do I mean to oversimplify this painful condition. Methyl B12 works hard in the body to reduce the amount of a pain-causing (and myelin-destroying) compound called methylmalonic acid.
Experts widely accept that the condition is an autoimmune process in which the white blood cells attack the myelin sheath. Methylcobalamin donates methyl groups to the myelin sheath that insulate nerve fibers and regenerate damaged neurons. But it goes much deeper than that, because methyl groups are not the only things that methyl B12 offers your myelin.
If you consume too much of an excitatory chemical called glutamate (yes, you get that from the MSG in thousands of food products), your nerve cells die. Methylcobalamin has been shown (you could even say proven!) to protect against glutamate-induced excitotoxic neuronal damage.
The cells most often affected by a B12 deficiency are called astrocytes and microglial cells. These are very interesting cells because they are highly reactive and can amplify immune mechanisms throughout the central nervous system, meaning that if it’s a good reaction, these cells break out their megaphones and tell the rest of the body, and if it’s a bad reaction, likewise. Trillions of cells in your body hear whatever these cells are saying. These astrocytes and microglial cells also help to clear glutamate, and without proper clearance the excess glutamate damages myelin. We always want to make nice with these cells and try our best to avoid irritating them. When we run out of B12, we irritate them.
There is a strong correlation between B12 deficiency and damage in the central nervous system because the deficiency sparks an inflammatory response and allows excessive glutamate to stay where it is. According to researchers at the University of Milan, animal studies suggest that the process goes something like this (and I’ve just cut to the chase here for reading ease):
A person becomes severely deficient in vitamin B12. Chemicals called cytokines are produced in greater amounts in the cerebrospinal fluid. These cytokines then attack and destroy the fragile myelin sheath. These myelinotoxic cytokines include TNF-alpha (tumor necrosis factor-alpha) and sCD40, another chemical related to TNF-alpha. Boom! Lesions form on the myelin, or it may start to unravel or decay. With continued production of inflammatory chemicals, this process progresses and sclerosis (scarring) occurs and the degeneration may spread along the spinal cord.
As if that’s not bad enough, this animal study also showed that the good stuff that helps myelin form was not being produced in high enough quantities. The researchers found a reduced synthesis of two neurotrophic agents, interleukin-6 and EGF (epidermal growth factor). This imbalance was also a result of cobalamin deficiency. Remember, B12 is a cobalamin. It’s methylcobalamin, to be exact.
The bottom line here is that you should never underestimate simple remedies. Our nerves don’t start to hurt because we suddenly run low on Vicodin or Lyrica (although these meds may be incredibly helpful and necessary at times). My point is that our nerves hurt because of neuro-chemical imbalances that trigger inflammatory chemicals. Vitamin B12 plays an important role in improving the metabolic pathways that form your myelin.
Some of the research I’ve been elaborating on was published in Progress in Neurobiology in 2009. The researchers made it clear that a deficiency of B12 leads to an increase in toxic chemicals that damage myelin. High levels of pain-causing chemicals and low levels of healthy growth factors were confirmed in people with severe B12 deficiency.
I’ve actually saved the best for last. In a 2005 study published in the Journal of the Neurological Sciences, Israeli researchers stated it best when they said this: “Multiple sclerosis and vitamin B12 deficiency share common inflammatory and neurodegenerative pathophysiological characteristics. Due to similarities in the clinical presentations and MRI findings, the differential diagnosis between vitamin B12 deficiency and MS may be difficult. Additionally, low or decreased levels of vitamin B12 have been demonstrated in MS patients. Moreover, recent studies suggest that vitamin B12, in addition to its known role as a co-factor in myelin formation, has important immunomodulatory and neurotrophic effects. These observations raise the questions of possible causal relationship between the two disorders, and suggest further studies of the need [for] close monitoring of vitamin B12 levels as well as the potential requirement for supplementation of vitamin B12 alone or in combination with the immunotherapies for MS patients.”
Aren’t you glad you learned that? Now you have the knowledge to protect your precious nerve fibers. And B12 won’t interact with any of your medications either. It’s as natural to you as green is to plants! Physicians often prescribe antiseizure medications, narcotic pain relievers, and interferon to treat neurological disorders, neuralgia, and nerve pain. But in my book nothing is wrong with adding vitamin B12 (specifically, methylcobalamin) to help you rebuild the coating around your nerves.
Many doctors still say that it’s impossible to regenerate human nerve cells and improve painful neuropathies associated with myelin degeneration. Yet a study in the Journal of the Neurological Sciences published way back in 1994 found that methylcobalamin could trigger nerve regeneration in lab rats.
And back in 1983 a study published in the Russian journal Farmakolologia i Toksikologiia showed that the daily administration of methylcobalamin to rats markedly activated the regeneration of mechanically damaged neurons. Finally, two studies published in 1976 in the Japanese journal Nippon Yakurigaku Zasshi showed that B12 administration resulted in greater protein synthesis and neural regeneration.
Okay, I’m done with the studies for now. That was a lot of science to absorb, but it was important to include it here because so many doctors maintain that vitamins will not help something like MS. Given that these studies showing otherwise are out there, and that vitamin B12 is safe, it makes sense to make this nutrient a part of the treatment plan for MS.
I also think it can help people with trigeminal neuralgia, shingles, neuropathies, problems with visual accommodation, neurological disorders, painful mouth sores, memory loss, and other autoimmune diseases (besides MS) in which demyelination is the underlying problem. Cyanocobalamin won’t help these conditions to the extent that methylcobalamin will, so if you are going to supplement, use the superior form.
Vitamin B12 is also useful in preventing heart disease. In Chapter 9 on vitamin B9, or folate, I discussed how B9 helps reduce homocysteine, an inflammatory substance that contributes to heart attack risk. B12 also reduces the homocysteine level, but only in the methyl form. These two Bs work better together to lower homocysteine.
I’ve also seen vitamin B12 supplements cure depression and memory loss. B12 deficiency can cause symptoms that look exactly like Alzheimer’s disease, primarily because the deficiency affects those astrocytes and microglial cells I told you about earlier. These cells get upset and create all those inflammatory chemicals that damage the cells in the brain that are responsible for memory. I’m not saying that myelin breakdown is the cause of Alzheimer’s, but it may contribute to it. Memory loss, fatigue, and mental confusion are usually the first signs of a vitamin B12 deficiency.
This reminds me of a story my friend Bill Shafer told me. Bill was one of the primary anchors for WESH TV news in Orlando for many years. He’s best known for his sense of humor and compassion. Now he and Marc Middleton head up a unique site for boomers, www.growingbolder.com. Since he’s very articulate, I’ve decided to let him tell you the story himself. Take it away, Bill.
My 87-year-old mother-in-law suddenly started having delusions. Before we knew what hit us, we were told that she had Alzheimer’s disease, and she was slammed into the mental ward of a psychiatric hospital for evaluation. Can you imagine how horrified and frightened she was?
My wife, Mary, was told to find a nursing home for her mother. Fortunately, she’s a voracious Internet researcher and a Suzy Cohen disciple. Something didn’t seem right. Mary saw that her mother’s B12 level was 202. Normal range is considered to be 200 to 900, but as we age, many believe, that number should be as close to the high end as possible. All of her doctors dismissed this lab value, then Mary found one who absolutely confirmed her suspicions. Her mother was prescribed daily, then weekly injections of methylcobalamin, and within a few short weeks her psychiatric symptoms and delusions completely disappeared. I’m happy to report that Mary’s mom is back at home, healthy, happy, and loving life. All because of B12.
When you run low on B12, you feel tired and could even experience profound fatigue and weakness, especially in the arms and legs. You may become depressed, and you could develop tongue, mouth, or gum sores, as well as pale skin and lips. Other deficiency symptoms include low appetite, confusion, and forgetfulness. A B12 shortage may also lead to easy bruising and peripheral neuropathy, a feeling of vibration or buzzing in the legs, and a pins-and-needles sensation in your hands and feet, like little bee stings everywhere but not quite that intense.
Vegetarians and vegans may become deficient in B12 because they do not eat meat, which is a source of B12. Anyone who drinks alcohol, deals with prolonged stress, or has had gastrointestinal surgery, nerve pain, chronic fatigue, or digestive disorders could also benefit from additional B12.
Many people run out of B12 because they are taking drug muggers of this nutrient. Junk food and refined white sugar also strip your gut of essential components that you need to make or absorb B12.
Acid Blockers
Cimetidine (Tagamet)
Esomeprazole (Nexium)
Famotidine (Pepcid and Pepcid Complete)
Lansoprazole (Prevacid 24HR)
Omeprazole (Prilosec OTC)
Pantoprazole (Protonix)
Rabeprazole (Aciphex)
Ranitidine (Zantac)
Antacids
Aluminum and magnesium hydroxide (Maalox, Mylanta)
Aluminum carbonate gel (Basaljel)
Aluminum hydroxide (Amphojel, AlternaGEL)
Calcium carbonate (Tums, Titralac, Rolaids)
Magnesium hydroxide (Phillips’ Milk of Magnesia)
Sodium bicarbonate (Alka-Seltzer, baking soda)
Antibiotics (just a few examples here, although there are many others)
Amoxicillin (Amoxil)
Azithromycin (Z-Pak)
Cefaclor (Ceclor)
Cefdinir (Omnicef)
Cephalexin (Keflex)
Ciprofloxacin (Cipro)
Clarithromycin (Biaxin)
Dicloxacillin (Dynapen)
Doxycycline (Doryx)
Erythromycin (E.E.S.)
Levofloxacin (Levaquin)
Minocycline (Minocin)
Sulfamethoxazole and trimethoprim (Bactrim Septra)
Tetracycline (Sumycin)
Anticonvulsants
Phenobarbital (Solfoton)
Phenytoin (Dilantin) (Space supplement at least 2 hours away from anticonvulsant medication.)
Primidone (Mysoline)
Antigout
Colchicine (Colcrys)
Antimetabolites
Methotrexate (Rheumatrex, Trexall)
Antivirals
Foscarnet (Foscavir)
Lamivudine (Epivir)
Stavudine (Zerit)
Zidovudine, AZT (Retrovir)
Zidovudine and Lamivudine (Combivir)
Blood Pressure Drugs
Methyldopa (Aldomet)
Cholesterol Medicine
Fibrate cholesterol medicine:
Clofibrate (Atromid-S)
Ezetimibe (Zetia)
Fenofibrate (Tricor)
Gemfibrozil (Lopid)
Bile acid sequestrant medicine:
Cholestyramine resin (Questran)
Colestipol (Colestid)
Colesevelam (Welchol)
Diabetes Medications
Glimepiride (Amaryl)
Glipizide (Glucotrol)
Glyburide (Diabeta, Glynase, Micronase)
Glyburide and metformin (Glucovance)
Metformin (Fortamet, Glucophage, Glucophage XR, Glumetza, Riomet)
Metformin and sitagliptin (Janumet)
Pioglitazone (Actos)
Rosiglitazone (Avandia)
Hormone Replacement Therapy/Oral Contraceptives
Estradiol (Activella, Climara, CombiPatch, Estraderm, Estring, EstroGel, Menostar, and many others)
Estrogen-containing drugs (Estrace, Femring)
Estrogens, conjugated (Prempro, Premphase)
Ethinyl estradiol (found in many birth control pills)
Norethindrone (Aygestin)
Nonsteroidal Aromatase Inhibitors for breast cancer
Anastrozole (Arimidex)
Parkinson’s drugs
Levodopa/carbidopa (Sinemet)
Psychiatric Drugs
Chlorpromazine (Thorazine)
Fluphenazine (Prolixin)
Haloperidol (Haldol)
Thioridazine (Mellaril)
SERMs (Selective Estrogen Receptor Modulators—used for breast cancer)
Raloxifene (Evista)
Tamoxifen (Nolvadex)
Toremifene (Fareston)
MISC:
Alcohol
Any drug mugger of beneficial bacteria
Estrogen dominance Hypochlorhydria (low stomach acid)
Infection with H. pylori bacteria
Potassium supplements and drugs (Micro-K, Slow-K)
Vegetarian or vegan diet
Primarily animal foods: beef liver, liverwurst, snapper, venison, shrimp (cooked), scallops, salmon, beef, lamb, cod, oysters, sardines, clams, flounder, halibut, yogurt, cow’s milk, blue cheese, and eggs. Other sources: spirulina, brewer’s yeast, tempeh, miso, and tofu.
For general health: 250–500 mcg per day
Drug mugger dose and vegetarians: 1,000–5,000 mcg methylcobalamin per day (reduce dose after 1 or 2 months), along with a B complex to give you the full range of benefits. You can take the supplement orally or under the tongue (sublingually). You can also get injections to be administered by yourself or by a nurse.
Methylcobalamin is the best form of the supplement. This is also called the methylated form of B12. It’s the active form that makes its way into the brain and nervous system, so it helps all kinds of neurological conditions.
Many people looking for B12 make the mistake of buying cyanocobalamin, which is not natural. It’s a semisynthetic version of the real deal. It’s generally considered to be safe, and it’s found in hundreds of supplements worldwide. As its name suggests, cyanocobalamin has a water-soluble cyanide group attached to its chemical structure, whereas methylcobalamin carries a methyl group. This is a very important distinction. The body’s natural stash of B12 is in the adenosylcobalamin form, not the methyl or cyano forms. The methyl in methyl B12 helps lower homocysteine, an inflammatory chemical in the body that raises your risk of heart disease. Also, methyl B12 is the only form that can help you generate an important antidepressant and pain-relieving chemical called SAMe (S-adenosyl-L-methionine).
Remember I told you that people with low B12 look like they have Alzheimer’s? Well, a study published in January 2010 found that people with Alzheimer’s have low levels of SAMe in their brains. You can buy supplements of SAMe at any pharmacy or health food store, but you can also make this incredible substance yourself when you have methyl B12 on board, not cyano. Indeed, the ability of B12 to protect nerve cells may also be thanks to the increased SAMe in the body.
Cyanocobalamin is extremely popular and sold nationwide. But since you are reading my book and want my opinion, I am gently pushing you (okay, maybe I’m shoving a little, but I really care) toward methyl B12. Methyl B12 is better absorbed, and tissues retain it better. I want you to break out your magnifying glass and make sure your product says methylcobalamin on the label, not cyanocobalamin. I’m suggesting that you do this because your liver has to spin cartwheels in order to process the cyano type. Your liver and kidneys have to go through a time-consuming and taxing chemical reaction to jettison the cyanide molecule and convert the cyanocobalamin into methylcobalamin. Don’t freak out, though. You’re not going to die from cyanide poisoning if you take the inferior version; there’s not enough of it.
The absorption of vitamin B12 depends on the presence of intrinsic factor, which is made in the GI tract. Many people do not have enough intrinsic factor to absorb B12 from their food or supplements. That’s one reason why maintaining gastrointestinal health is important. (For more on this, read Chapter 17 on probiotics on page 221.) People who opt for injections of B12 almost exclusively get cyanocobalamin, not methylcobalamin. I don’t recommend the cyano form for injections either. To get the methylcobalamin in an injectable form, you’ll have to ask your doctor. (Okay, you’ll actually have to nag!) And he or she will have to phone the local compounding pharmacy and ask them to make it.
Compounding pharmacies have the formula and make excellent, pure versions of injectable methylcobalamin all the time for the holistic-minded physicians in the area. Honestly, they know what they’re doing. To find a compounding pharmacy, look in your Yellow Pages. If you can’t find one there, contact the International Academy of Compounding Pharmacists at 800-927-4227 or www.iacprx.org. You can also try the Professional Compounding Centers of America at 800-331-2498 or www.pccarx.com.
If needles bother you or you just don’t want to deal with the hassle of a prescription injectable form, then get an oral version of methylcobalamin; these supplements are sold at all health food stores. My point is: Get the methyl B12 in any dosage form before you take cyano B12. Studies have compared the two versions, and the methyl version always comes out on top. The studies are clear and undebatable. Individuals who took the natural methylcobalamin form of B12 showed better concentration, exhibited more alertness, and experienced sleep that left them more refreshed.
You can expect to pay more for methylcobalamin, but in my opinion it’s totally worth it. For the injectable version, we’re talking something that costs $45 versus $15. So it’s not a mortgage payment or anything. Oral supplements are $10 to $20 a bottle.
There is a low incidence of toxicity associated with methyl B12, even at very high doses. With cyanocobalamin, on the other hand, it’s easier to get excessive amounts and experience side effects. That’s because your body has to do more processing with cyanocobalamin, and tiny amounts of cyanide molecules may accumulate over time and cause subtle vision damage.
For whatever reason, if you have to take the cyano form of B12, my best advice is to take it for only a few months or less, especially if you are taking relatively high dosages. Taking large doses of any form of B12 (methyl or cyano) will tilt all your vitamin Bs out of ratio. Some people just naturally have a lot of B12 to begin with. Very often, people with mitral valve prolapse or rheumatoid arthritis have higher levels of B12 and/or cobalt levels, so taking high supplemental doses could be harmful. It may not be wise for people with schizophrenia to take high doses of B12 either, except on the advice of their doctors.
Medical experts maintain that no amount of B12 will help you if you take the supplement by mouth and happen to lack intrinsic factor in your digestive tract. This substance is a protein secreted by certain cells in the stomach. In humans, it aids in the absorption of vitamin B12 from your intestine. If you can’t make or use intrinsic factor properly, the condition of B12 deficiency (pernicious anemia) results. So one way to install a foolproof security system and be 100 percent sure you’re getting methyl B12 is to bypass your digestive tract. There are three ways to do that:
1. Take methyl B12 tablets sublingually (so it goes from your mouth to your bloodstream).
2. Take methyl B12 shots intramuscularly (so it goes from muscle into your bloodstream).
3. Take methyl B12 formulas that are combined with intrinsic factor (which gives you a better chance of absorbing B12 if you don’t make it yourself).
The B vitamins are interdependent. In other words, it’s very easy to tilt your Bs out of their perfect balance. If you take B12 chronically, you may become deficient in another B vitamin. So whenever you take high doses of a single B vitamin, take a B complex as well so that the other Bs are on board. If you take high doses of B12 only occasionally or daily, but for less than a month or two, then you don’t need the B complex.
Preferred Sublingual Methyl-B12 by Applied Health: These tablets give you B12 in the proper methyl form, providing 5,000 mcg (5 mg) in one naturally sweetened cherry tablet. Many people require large doses of B12, and this product provides just that. Speak to your doctor about substituting this formula for prescribed injections of B12. (Hey, who likes needles, anyway?)
Methylcobalamin by Life Extension: Each dissolvable lozenge contains 5,000 mcg. The formula does not contain any artificial sweeteners, colorants, gluten, or milk. This is another strong version of B12 that could be taken if you’re needle shy.
Sublingual B12 by ProThera: Each chewable tablet contains 5,000 mcg methyl B12.
B12 Infusion by Enzymatic Therapy: This product contains pure methylcobalamin in a chewable tablet offering 1,000 mcg per dose. It is free of yeast, dairy, and gluten. Because it is all natural, color variations may occur in the rapidly absorbed tablets.
Methyl B-12 1000 by Jarrow Formulas: These lozenges taste really good and are free of all allergenic ingredients. I often carry some of these in a little pill case in my purse for a quick pick-me-up. They also come in a 5,000 mcg strength.
Methylcobalamin lozenges by KAL: Each lozenge contains 1,000 mcg methyl B12 in a natural berry flavor.
Advanced B-12 Complex by Source Naturals: This formula contains both methyl B12 and another active form of B12 called adenosylcobalamin, providing B12 in two highly usable forms. It also contains some folic acid since B12 works better when its partner folic acid is hanging around.
B-Complex #12 by Thorne Research: I like this formula because it contains two active forms of B12 as well as all the active versions of the other B vitamins. So it’s a full B complex with lots of B12.