The vital role of vitamin B12: From energy production to brain health

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When it comes to brain and nerve health, vitamin B12 is a true powerhouse—yet many people don't realize how critical it is. B12 deficiency can lead to serious neurological problems, from cognitive changes and memory loss to nerve damage and balance issues. And the concerning part? Many people don't know they're deficient until symptoms become noticeable.

Why B12 is crucial for your whole body

Vitamin B12 (cobalamin) is essential for maintaining the protective coating around nerves (myelin), producing neurotransmitters—the chemical messengers your brain uses to function—and forming healthy red blood cells that transport oxygen throughout your body. Without adequate B12, your nervous system can't work properly, leading to a range of neurological symptoms that often develop gradually and can be mistaken for other conditions.

 Up to 38% of older adults have insufficient vitamin B12—either deficiency or depleted stores. 

What is vitamin B12 and why does it matter for neurological health

Vitamin B12 is a water-soluble vitamin essential for red blood cell formation, neurological function and DNA synthesis. It plays a critical role in maintaining myelin—the protective sheath around nerves—and in producing neurotransmitters that regulate mood, memory and cognitive function.

Research consistently shows that vitamin B12 plays a vital role in brain and nerve health. Low B12 levels have been associated with:

  • Cognitive decline — Memory problems, difficulty concentrating, and mental fog
  • Peripheral neuropathy — Tingling, numbness, and weakness in the hands and feet
  • Balance and coordination issues — Increased fall risk and gait disturbances
  • Mood changes — Depression, anxiety, and irritability

B12 and energy: The red blood cell connection

Vitamin B12 is essential for red blood cell formation. These cells transport oxygen throughout your body—when B12 levels are low, red blood cell production suffers, leading to a type of anemia that causes fatigue, reduced exercise capacity, and overall weakness. B12-related anemia can develop gradually and go unnoticed until symptoms significantly impact your daily life.

“Screening B12 levels is just the first step. When we’re able to understand why B12 is low, we can correct levels with small changes (food or supplements) or work with your physician or nurse practitioner who may prescribe B12 injections. Taking action can have such an impact on a client’s daily life.”

—Heather Vass, Registered Dietitian, TELUS Health Care Centres

Who is most at risk for B12 deficiency?

B12 deficiency is more common than many people realize. Certain groups are at higher risk:

  • Adults over 50 — Reduced stomach acid production with age impairs B12 absorption from food.
  • Those following plant-based diets — B12 is found almost exclusively in animal products, making deficiency common among vegans and vegetarians.
  • People taking certain medications — Long-term use of metformin (for diabetes) or proton pump inhibitors can reduce B12 absorption.
  • Those with gastrointestinal conditions — Conditions like Crohn's disease or celiac disease can impair nutrient absorption.

According to guidelines, B12 deficiency is often underdiagnosed because symptoms develop gradually and can be mistaken for other conditions, including fatigue, cognitive changes and balance problems.

How to get enough vitamin B12

Health Canada recommends that adults aim for 2.4 micrograms (mcg) of vitamin B12 per day. Adults over 50 are advised to meet their needs primarily through fortified foods or supplements, as the crystalline form of B12 in these products is more easily absorbed than the protein-bound form found in food.

Top food sources of vitamin B12

Food Amount
Nutritional yeast ~8 mcg per 2 tablespoons (fortified)
Nutritional yeast ~8 mcg per 2 tablespoons (fortified)
Salmon ~3.2 mcg per 75g serving
Beef ~2.5 mcg per 75g serving
Milk ~1.1 mcg per 250mL cup
Eggs ~0.6 mcg per large egg
Cheese ~0.5 mcg per 50g serving

For those following plant-based diets, fortified plant-based beverages (such as soy or oat milk), nutritional yeast and B12 supplements* are important alternatives.

Looking for personalized nutrition support? Our registered dietitians can help you develop an eating plan or recommend supplements that help ensure you are getting adequate B12 and other key nutrients for energy, nerve, and brain health.

Taking a proactive approach to your health

Neurological symptoms from B12 deficiency can develop gradually and are often overlooked until they become serious. Knowing your B12 levels and other key health markers gives you and your care team the information needed to take action early, when it matters most.

A comprehensive health assessment can help identify nutritional gaps, assess your risk factors and provide personalized recommendations to support your long-term brain health and overall vitality.

* This article is for educational purposes only and should not be considered medical advice. Please consult with a healthcare practitioner before making dietary changes or starting supplements.

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