What is Vitamin B12? Vitamin B12 is a nutrient your body needs but can’t make on its own. You get it from food - mainly meat, fish, eggs, and dairy - or from supplements.
It plays an important role in how your body makes red blood cells, uses energy, and keeps your nervous system working properly. [13] Because B12 is involved in so many everyday processes, running low can show up in ways you might not expect.
Vitamin B12 deficiency is also more common than many people realise - particularly in older adults, vegetarians and vegans, and people taking certain medications
10 Signs Of Low B12
Please note: the symptoms listed in this article can be caused by lots of different things - not just low B12. If any of them sound familiar, the best thing to do is speak to your GP. This article is here to help you learn, not to replace medical advice.
1. Persistent Fatigue
Constant tiredness that doesn’t improve with rest is one of the most common signs of vitamin B12 deficiency. B12 helps your body make red blood cells, which carry oxygen to your muscles and organs. When your B12 levels are low, you may produce fewer of these cells - and that can leave you feeling exhausted. ¹ ²
2. Shortness of Breath
Reduced red blood cell production can make physical activity feel more difficult than usual as your body struggles to meet the extra demand for oxygen ¹ .
3. Muscle Weakness
Many people report feeling physically weaker or more easily exhausted when B12 levels drop When your blood isn’t carrying enough oxygen around your body, even simple activities can feel harder than they should ¹ ³.
4. Difficulty Concentrating
Vitamin B12 supports normal psychological function. ¹³ Some research in older adults has found a link between low B12 levels and difficulties with memory and focus. [12] These effects tend to be subtle, but if you’ve noticed you’re not as sharp as usual, it may be worth getting your levels checked. ¹²
5. Low Mood
Some studies have found that people with low vitamin B12 are more likely to experience symptoms of low mood. ⁵ ⁶ The relationship is still being studied and isn’t fully understood, so B12 supplements shouldn’t be seen as a treatment for depression. If you’re struggling with your mood, please speak to your GP or a mental health professional.⁵
6. Headaches or Migraines
A small number of studies have observed a possible link between low vitamin B12 and more frequent migraines. ⁷ However, headaches have many different causes, so its always best to investigate.
7. Pins and Needles
Vitamin B12 helps protect the coating around your nerves (called the myelin sheath). When levels stay low for a long time, that protective layer can become damaged - which may cause tingling, numbness or a “pins and needles” sensation, usually in the hands or feet. ² ³ This is one of the more distinctive signs of B12 deficiency and is well supported by medical research .⁶
8. Balance Problems
In more serious or long-standing cases of vitamin B12 deficiency, nerve damage can affect your sense of balance and coordination. This usually only happens when deficiency has gone unnoticed for a long time. ³ If you’re experiencing these symptoms, it’s important to see your doctor.
9. Pale Skin
When your body isn’t making enough healthy red blood cells, it can sometimes show in your skin. You might look paler than usual, or notice a slightly yellowish tint. This happens because the abnormally large red blood cells produced during B12 deficiency are fragile and break down more easily than normal. ¹
10. Tongue Inflammation
An inflamed tongue - known medically as glossitis - is a recognised sign of vitamin B12 deficiency. It may look unusually smooth and feel sore or tender. ¹ While this can have other causes, it’s one of the symptoms that healthcare professionals look for when assessing nutritional status.
WHY B12 DEFICIENCY IS MORE COMMON THAN EXPECTED
Recent research shows B12 deficiency affects more people than previously thought¹. And diet alone doesn’t explain it.
Aging: As we get older, stomach acid levels naturally decline. This makes it much harder for the body to "unlock" B12 from the proteins in our food. ¹ ⁴
Medications: Certain medications can interfere with B12 absorption. A major clinical trial showed that metformin (for diabetes) can drop B12 levels by 19% over four years. ⁸ Acid reflux medications (PPIs) have a similar effect by reducing the stomach acid needed for absorption. ¹
Digestive Conditions. If your digestive system is compromised by conditions like coeliac disease, Crohn’s, or atrophic gastritis, your body may struggle to absorb B12 regardless of your intake. ¹
WHY B12 TABLETS MIGHT NOT BE AS EFFECTIVE
Traditional B12 tablets depend pn your digestive system function
They rely on:
1. Adequate stomach acid
2. Functional intrinsic factor
3. A healthy digestive tract²
If any part of this system isn’t working optimally, absorption may be sub optimal.
That’s one reason many people are now looking at alternative delivery methods.
WHY THOUSANDS OF PEOPLE ARE SWITCHING TO LIQUID B12
Standard B12 tablets rely entirely on digestion.
Sublingual B12 works differently. Instead of relying entirely on digestion, absorption can begin in the tissues of the mouth before the remainder is swallowed².
Clinical research comparing sublingual, and injectable vitamin B12 supplementation including analyses involving thousands of patients with deficiency shows that all methods effectively raise vitamin B12 levels⁹.
Because sublingual supplements rely less on digestive absorption, they are often used as a practical option when absorption may be reduced.