When life gets busy, it’s easy to chalk up low energy, foggy thinking or mood dips to stress, lack of sleep, or just having too much on your plate. These symptoms often become part of the background—easy to ignore when there’s no time to slow down.
But sometimes, they’re your body’s way of signalling that something’s off.
One possible reason? These are signs of vitamin B12 deficiency. In this blog, we’ll unpack some of the most common signs of low B12, what causes it, and how to restore healthy levels through food, supplements and lifestyle support.
What Are the Signs of Vitamin B12 Deficiency?
Vitamin B12 deficiency can lead to a wide range of symptoms that often appear gradually, including fatigue, brain fog, mood changes, and tingling in the hands or feet. These signs are linked to B12’s role in supporting red blood cell formation and nervous system function (1).
What Does Vitamin B12 Actually Do?
Vitamin B12 (cobalamin) is essential for several biological processes. Research highlights (2) that it:
- Supports brain function
- Helps make red blood cells
- Aids DNA production
- Keeps energy levels steady
- Protects your nervous system
Fun Fact: Your body can’t produce B12 on its own—you have to get it from food or supplements! (3).
What Are the Most Common Signs of Vitamin B12 Deficiency?
Vitamin B12 deficiency may present with a range of signs, but these can vary in severity and often overlap with other health issues. According to the John Hopkins Medicine (4), possible symptoms may include:
| Symptoms | What’s Happening to the Body |
| Persistent Fatigue | May be linked to reduced red blood cell production |
| Memory Difficulties or Brain Fog | Could reflect B12’s role in nerve and brain function |
| Tingling Sensations | Prolonged deficiency may affect peripheral nerves |
| Mood Changes | Some studies associate low B12 with altered mood chemistry (3). |
| Pale or Yellowed Skin | Potential result of impaired red blood cell production |
| Swollen Tongue | Documented in some deficiency cases (1). |
If these sound familiar, you’re not alone. According to the Cleveland Clinic (5), B12 deficiency is more common than many realise, especially in older adults, vegans, vegetarians, and those with digestive issues that affect nutrient absorption.
What Causes B12 Deficiency in the First Place?
There’s no one-size-fits-all answer, but there are several factors that can lead to low B12 (6):
- Dietary gaps – B12 is found in animal products, so vegans and vegetarians are at higher risk
- Digestive issues – Conditions like coeliac, Crohn’s, or low stomach acid can block absorption
- Ageing – As we age, our bodies absorb B12 less efficiently
- Medications – Certain heartburn drugs and metformin can interfere with absorption
- Recent surgery or chemo – These put extra strain on the body and may affect nutrient uptake
These factors highlight how B12 deficiency can result from more than just diet—it’s often influenced by age, digestive health, medical conditions, or medications. Understanding the underlying cause is an important step toward addressing low B12 levels effectively.
How Can You Restore Your Vitamin B12 Levels?
Once low levels are identified, steps can be taken to support your body in restoring adequate B12 status.
Step 1: Load Up on B12-Rich Foods
Start with your plate. B12 is naturally found in:
- Eggs and dairy (cheese, milk, yoghurt)
- Meat, particularly liver and red meats
- Fish like salmon, sardines, tuna, and trout
- Fortified plant-based products (such as cereals and soy milk)
For vegetarians and vegans, fortified foods are your best friends. Check the labels—some products pack a powerful B12 punch!
- For a deeper look at what foods contain Vitamin B12, read here: What Contains Vitamin B12? Best Food & Supplement Sources
Step 2: Choose the Right Supplement
Not getting enough through diet alone? Supplements can help fill the gap. You can find B12 in:
- Daily tablets or capsules – great for long-term support
- Sublingual drops or sprays – ideal for faster absorption under the tongue
- Multivitamins with added B12 – a convenient option for broader health coverage
- For a deeper look at Vitamin B12 supplements, read here: Pros and Cons of Vitamin B12: Should You Take a Supplement?
Step 3: Support Your Whole Body Health
Vitamin B12 levels don’t exist in isolation—they’re often influenced by broader factors like gut function, stress, and how well your body absorbs nutrients. Even with a diet that includes B12-rich foods, issues in the digestive system can prevent your body from accessing what it needs.
That’s why it’s important to take a whole-body view when addressing deficiency. Exploring areas such as gastrointestinal health, underlying medical conditions, and lifestyle stressors can help identify the root cause of low B12, allowing for more targeted and lasting support.
Let’s Talk Health—The Holistic Response to Vitamin B12 Deficiency
Understanding the signs of vitamin B12 deficiency—and knowing how to restore healthy levels—is an important step toward supporting your overall wellbeing. Whether you’re experiencing symptoms or simply want to stay informed, taking a closer look at your B12 intake can offer valuable insight into your health.
If you’re unsure where to start or want personalised guidance, support is available. You can learn more about tailored, evidence-based approaches to nutrition and wellness by getting in touch with Natural Immunity.
Sources: