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Welcome to the "Know Your Numbers" series, your go-to guide for understanding the lab results behind your health. In Part 5, we’ll dive into Vitamin B12: what it really is, why your levels matter, and whether that energy boost from supplements is fact or fiction. From symptoms of deficiency to who’s most at risk, we’re breaking it all down in plain language. Get empowered to make sense of your bloodwork and take charge of your energy levels, without the guesswork.

Let’s get into it! 👏

✍️🔍What is vitamin b12?

Vitamin B12 is an essential nutrient, meaning your body can’t produce it. You either have to get it from your diet or supplements. The most common dietary source? Animal products, especially meat.

B12 plays a crucial role in keeping your brain sharp, your energy stable, and your body functioning optimally.

**🔬SYMPTOMS OF VITAMIN B12 DEFICIENCY**
When B12 levels are too low, your body doesn’t have what it needs to run efficiently. Common signs of deficiency include:
➡️Fatigue and weakness
➡️Brain fog
➡️Low mood
➡️Nerve-related symptoms like tingling or numbness
➡️Soreness in the mouth or tongue
**Important caveat:** Having these symptoms doesn’t automatically mean you’re B12 deficient, but if you *are* low, addressing it can significantly improve how you feel.

Who’s at Risk for Low B12?

B12 deficiency can affect anyone, but you’re more likely to be low if:

You follow a vegetarian or vegan diet
You have digestive conditions (like celiac disease or Crohn’s)
You’re taking certain medications, such as:

Metformin (for blood sugar)
Proton pump inhibitors or antacids (for heartburn)

You’re over the age of 60 (natural aging affects absorption)

Because it’s so common, and easy to treat, I recommend testing B12 levels for most of my patients.

How Is B12 Tested?

Vitamin B12 levels are checked with a simple blood test.

Here’s what I look for:

Anything under 220 pmol/L is considered low (this used to be <135, so the range has improved!)
I aim to see levels above 300 pmol/L for optimal health

Tip: If you're taking a B12 supplement (or even a multi or B-Complex), stop it a few weeks before testing to get an accurate baseline. The bloodwork really picks up supplementation so it can look falsely high!

so, your levels are low. What’s the Best Way to Supplement B12?

Supplementation works best when tailored to you. There are two main forms:

Sublingual (under-the-tongue) supplements:

Great for mild to moderate deficiency
Bypasses the digestive tract for better absorption

Intramuscular (IM) injections:

Delivers B12 directly into the bloodstream for fast, reliable absorption
Ideal for those with:
- Digestive issues
- Very low B12 levels
- A family history of pernicious anemia

Both forms are great for most people, but there is a small percentage of people where sublingual supplements are inadequate.

Intra-muscular injections are in my scope of practice as a Naturopathic Doctor and can be a great option for those who struggle to take supplements, those with digestive concerns or very low B12.

Feeling Tired or Foggy? Let’s Find Out Why.

If you’re concerned about your B12 levels, or just tired of feeling tired, testing is the best first step. It’s quick, affordable, and can make a world of difference in how you feel day to day.

Book a visit to check your B12 and take the guesswork out of your energy levels.

book a visit today