Guest Author: Seth Kaplan
When you take a multivitamin or individual supplements, do you check the labels to see which form of the vitamins you are getting? I do, and I think more consumers are paying attention to what they eat than ever before. Turns out, this is important to do for just about all the vitamins, minerals, trace minerals, and other substances. Taking the wrong form can at best be benign; at worst, serious problems can result. Today, I shall walk you through the basic knowledge you should have about Vitamin B-12.
B-12 Basics, Functions, and Forms
Unless you are a chemist, looking at the structure of a B-12 molecule will make your head spin. It is the most chemically complex of all vitamins, and is grouped under the general heading of “cobalamins.” It is also harder to get adequate amounts of B-12 because plants, animals, and fungi do not make it. Vitamin B-12 can be made in the human digestive tract through a series of complex interactions, but the amount made will vary with each individual, so insufficiencies can occur. In fact, up to 40% of Americans, especially vegans and seniors, have some form of a Vitamin B-12 deficiency and must supplement.
For years, I thought that B-12 came in just two forms: cyanocobalamin and methylcobalamin. This past week I was surprised to learn of two other B-12 forms: hydroxocobalamin and adenosylcobalamin. For reason which will become clear in a moment, you won’t find the latter two on nearly all labels for multivitamin, B-complex, and other products containing B-12.
- Cyanocobalamin is synthetic B-12, so it is the least expensive of the four; as a result, this is the form you will find in many products. It is also the most stable form of B-12, thanks to a cyanide molecule. Not to worry! The amount of cyanide is not harmful to humans, but it does make this form hard to absorb. It’s NOT the one you want to take, though.
- Methylcobalamin, however, IS the B-12 supplement you want. It is the most bioactive form of B-12, which may have something to do with B-12’s multiple functionalities:
- It converts homocysteine into methionine, which helps produce protein and protects the cardiovascular system.
- Because it can cross the brain’s blood-brain barrier, this B-12 form is essential for the growth and protection of the nervous system, especially in slowing down progression of diseases like Parkinson’s, multiple sclerosis, and other neurological disorders.
- This form of B-12 plays a role in energy production (think ATP-adenosine triphosphate; no ATP, no giddyup), preventing anemia, producing acetylcholine, and helping to promote sleep.
- Hydroxocobalamin, created by bacteria, is the form most found in foods. In the body, it converts into methylcobalamin. It is the form most often used to transfuse someone with a deficiency.
- Adenosylcobalamin, the last form, helps with something called the Citric Acid cycle, an important part of energy production. Only one product, Vegansafe™, contains it because it is hard to stabilize the molecule. However, the combination of methylcobalamin and adenosylcobalamin works best in the human body.
Overcoming Absorption Issues
Many seniors have trouble absorbing B-12 because they do not make enough digestive acid. But, lots of nutrients and other substances can affect the body’s ability to absorb Vitamin B-12. These include:
- Anti-gout medications
- Potassium supplements
- Not having enough intrinsic factor
The last item may be the most important. The body produces intrinsic factor in the GI tract to help with B-12 absorption. Reasons abound why a body doesn’t have enough intrinsic factor: Dietary MSG (monosodium glutamate); pernicious anemia; leaky gut; gluten sensitivity; the body does not make enough; and others.
Regardless of the explanation, though, there is a simple solution: sublingual B-12. Many companies make B-12 lozenges that dissolve under the tongue, which means the B-12 passes right into the blood stream without having to go through the digestive tract. Problem solved.
Some people who, for extreme health reasons, need large infusions of B-12, often receive it through injections, usually once a month.
Remember: If you think you may not be getting enough B-12, ask your doctor to test your blood levels. Once it is determined that you need a B-12 supplement, make sure you get a product with methylcobalamin. How big a dose you should take is a matter of trial and error; no one size fits all.
Since the Daily Value for B-12 is 2.4 mcg—that’s micrograms—you will need more. The usual doses available start at 250 mcg and go up to 10,000 mcg. This is NOT a case of more is better. Find the lowest dose that addresses your symptoms. Talk to your pharmacist, too. But, you are the one who must do the leg work, and that starts with reading product labels.