“Could Low B12 Be the Reason You’re So Tired?”

By Lucy Sugars, Nutritional Therapist

Feeling constantly tired, foggy or flat — despite sleeping well and eating “okay”?
You might want to check your vitamin B12 levels. This vital nutrient plays a central role in energy production, brain function, and nervous system health — so when levels drop, you can really feel it.

Common Signs of Low B12 Levels

I often see B12 deficiency show up in a range of symptoms, including:

  • Persistent fatigue, even after rest
  • Feeling sleepy during the day
  • Poor sleep or trouble staying asleep (yes, the irony!)
  • Low mood, anxiety or even panic attacks
  • Brain fog, poor memory or word recall
  • Tingling or pins and needles in hands or feet
  • Dizziness or balance issues
  • Shortness of breath after light activity (like going upstairs)
  • Pale skin or unexplained weakness

These symptoms can overlap with other conditions too, so it’s important to check with your GP or health practitioner if anything new or persistent arises. But B12 deficiency is surprisingly common — and often overlooked. There is a good resource to look at with a very comprehensive list of low B12 signs and symptoms available here.

Why Might B12 Be Low?

There are two main reasons:

1. Low Intake from Food
B12 is found mostly in animal-based foods such as meat, fish, eggs and dairy. So vegetarians and vegans are at higher risk. But even meat-eaters can have low B12 — especially if absorption is an issue.

2. Absorption Problems
You may be eating enough, but your body may struggle to absorb it properly. This can happen if you have:

Pernicious anaemia – an autoimmune condition that reduces your ability to absorb B12

Low stomach acid – due to age, stress or acid-suppressing medications (like PPIs)

Digestive conditions – such as Crohn’s disease, Coeliac disease, ulcerative colitis, or SIBO

Gut infections or parasites

Atrophic gastritis – where the stomach lining becomes thin and less effective

These issues are especially common in people with long-term gut problems or chronic stress.

Risk Factors for B12 Deficiency

You may be more at risk if you:

  • Have a family history of B12 deficiency
  • Already have an autoimmune condition (like Hashimoto’s, Graves’, Lupus or MS)
  • Are over 60
  • Follow a vegan or mostly plant-based diet
  • Take medications that affect stomach acid like PPI’s

What Can You Do?
If any of the above feels familiar, I recommend checking your B12 levels. A simple at-home blood test can give us a clear picture.

If your levels are low or suboptimal, we can look at:

  • Dietary adjustments to increase B12-rich foods
  • Professional-grade supplements (sometimes high doses are needed)
  • Supporting your gut health and absorption — which is often the missing link

Final Thoughts

Don’t wait for things to get worse before investigating. B12 deficiency is common, often missed, and very treatable — especially when caught early.

If you’re feeling persistently tired or dealing with brain fog, mood dips or gut health issues, get in touch to book an appointment. Let’s check your levels and support your energy from the inside out.