All About B12

Energy, Mood, Weight Loss and More

Stacey Baganz, BCHN

Oct 22, 2023

Today is all about Vitamin B12, aka Cobalamin.

What does it do?

Is your doctor testing the right marker to assess the true nutrient status in your body?

Should you be taking B12 as a supplement? And in what form?

What causes you to be deficient?

Let’s dig in.

WHAT DOES VITAMIN B12 DO?

Vitamin B12 is used in the body as a cofactor in many aspects of metabolism (energy production).

Most people think to supplement with B12 when they have low energy or fatigue or possibly mood issues. This is because:

1. B12 (along with its best friend folate) is essential for the first steps in making red blood cells – that’s why you can get “B12 anemia” that is unrelated to iron. Any impairment in red blood cell formation can make you tired since you are not able to effectively carry oxygen around to your cells

2. B12 is used in the Krebs Cycle (a process in our mitochondria where we make energy from the food we eat). Without B12 we cannot adequately utilize carbohydrates, fats, and amino acids. That’s probably why they tout it as helping in weight loss – when in reality it’s just helping your body boost metabolism to more effectively use food.

B12 is also touted as helping with neurological issues like mood, anxiety, or nerve damage in the extremities. That’s because it’s essential to the formation of myelin – the tissue that surrounds our neurons. Any impairment in this will lead to neurological and mood issues.

One of the most important, yet underrecognized features of B12 is that it helps to keep homocysteine low, one of the major independent risk factors in cardiovascular disease (yet most docs never test for homocysteine!). If you have high cholesterol, high inflammation, or any familial risk of cardiovascular disease, it’s time to put homocysteine on your radar.

HOW TO TEST FOR VITAMIN B12

Pull out your past labs and cross-reference this!

Serum B12 is the most common marker tested by doctors, and the optimal level is 450-1100 pg/mL or 332-811 pmol/L.

Now, while this is a start, you cannot rely on this one marker to adequately assess your B12 status. Why?

The body does not need, nor want to keep, nutrients in the blood serum. Measuring nutrient status in the blood serum does not assess intracellular levels or utilization.

When the body digests food, nutrients enter the blood from the GI tract and are immediately put onto a carrier molecule so they can be transported into cells that need them. Blood levels of nutrients are not an adequate marker of nutrient status, and may not reflect insufficiency. If you do see low serum levels of a nutrient, it is likely major disease processes are already underway and you’re going to be behind in the catch-up game.

Conversely, sometimes I have clients that have high levels of serum B12, and their docs have advised staying away from B12 supplements as they “have too much”. This is also not usually the case – high B12 serum doesn’t mean you are getting too much; it means you likely have an impairment in transporting it into the cell. Likely the cells are deficient and you need more!

In addition to B12 serum, you always also want to assess biomarkers related to B12 utilization to identify how it’s being used in the body. These include:

1. MCV (mean corpuscular volume) – this marker is found on the complete blood count and tells you how big your red blood cells are. Without B12, red blood cells won’t divide properly and get released into the bloodstream being too large. MCV should be between 82 and 89 fL. Over 90, and as MCV approaches 100, you show a high need for B12 and folate (and likely a higher probability towards B12 anemia).

2. Homocysteine – this marker is an independent risk factor for cardiovascular disease. I like to see it around 7, even though this is not the laboratory range. Anything over 9 indicates a higher need for B12 and folate.

3. Methylmalonic Acid (MMA). This metabolite pools in the blood or urine if B12 is deficient. It’s a step in your energy production pathway, thus if B12 is low, you will not be sufficiently generating energy in your body. Blood serum should be between 0-260 nmol/L. The DUTCH hormone test also measures for the urinary marker of this.

If these markers are off, you know that the body does not have enough B12 to effectively process the biochemical reactions in the body that are dependent on it. Likely then, there is an intracellular deficiency.

Genetics is also at play in a deficiency. The genes MTR and MTRR are the 2 key players in methylcobalamin use and regeneration. So any impairment in these 2 genes would make it so you require more B12 in the form of methylcobalamin.

WHAT CAUSES A B12 DEFICIENCY?

Let’s start with diet. B12 is mostly found in meat products. If you are a vegetarian or not eating adequate meat, you will likely need to supplement.

Next, evaluate your GI tract.

To get B12 from your food, you need adequate stomach acid. Stomach acid production can be impaired by infections like H.Pylori or giardia. Stomach acid also declines with age or any kind of inflammation in the gut (gastritis, bacterial overgrowth). Stress also stops the production of hydrochloric acid.

B12 is released from food by stomach acid, then it binds to a protein called intrinsic factor. Sometimes the body attacks itself and ruins the mechanism by which you make intrinsic factor (called pernicious anemia).

Bariatric surgery takes out the part of the GI tract where you absorb B12, so in this case, ongoing B12 injections would be warranted.

Medications can block B12 absorption. Most notable are antibiotics, birth control pills (and HRT!), indigestion medication (proton pump inhibitors, tums, anti-acids), histamine blockers, metformin, and nitrous oxide. Who knew that if you go to the dentist and get nitrous oxide you are going be irreversibly oxidizing methylcobalamin).

Lastly, alcohol gives a double whammy – it rapidly depletes B12 to detox it, while at the same time causing atrophy of the stomach lining so you can’t absorb it.

HOW TO REPLENISH B12

If you suspect any GI issues, it’s not advised to swallow B12 supplements until that piece is remedied. Time for a GI-MAP Stool Test to uncover what’s going on!

Sublingual B12 is the most effective oral route. The idea is that it bypasses digestion by passive diffusion into cells in the mouth (so long as you keep it in your mouth long enough).

Intramuscular injections of B12 are an option for bypassing digestion altogether. Locally here in Park City, I recommend visiting Prime IV Hydration and Wellness in Kimball Junction. If you are in another city, an option would be Ageless RX in which you can very affordably get them online and administer them to yourself.

Oral supplementation can be very effective so long as your GI tract is optimal. Always be sure you take it with food, because you need the acid in your stomach to work on it!

WHAT IS THE BEST FORM OF B12?

Always avoid the cheapest, and least absorbable form of B12 – cyanocobalamin.

It’s a fully synthetic form of B12, and there’s concern about the cyanide part of that molecule accumulating in the body and being toxic. Also, the body just doesn’t utilize it!

My personal opinion is that a mixture of B12 forms is best to meet metabolic needs.

Methylcobalamin is the methylated form of B12 and is best for lowering homocysteine and for detox. It’s best for red blood cell formation (if you have elevated MCV). And if you have any methylation issues (identified with a genetic test), then going straight for the methylated form is best.

Adenosylcobalamin is best for energy production, weight loss, and mood issues. It works inside the mitochondria and helps you best process the foods you eat into energy. Think low energy, weight loss, stamina.

Hydroxycobalamin is seen in some supplementation and used in some injectables and will be utilized by the body to make its own methyl or adenosylcobalamin.

My favorite sublingual: Neurobiologix Methylation Complete which has B12’s best friends methylfolate and B6 with it – they always work in synergy.

My favorite oral: Pure Encapsulations B6 Complex – it has high doses of B12 (in all the forms) plus all the other B’s which are synergistic.

Buy both of these on FullScript. Don’t have a FullScript account? Get one for 10% savings on thousands of physician-grade products. Become a client and get 20% off.

WANT TO KNOW YOUR B12 STATUS?

Reach out and let’s work together. Knowing your B12 status is just one of many things I look at when reviewing routine lab work to identify what nutrients your body needs.

Have questions about B12? Ask them here! Want to learn about another topic? Post suggestions here too.

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