Clues on your tongue could point to years of vitamin B12 deficiency - what to look for

A little-known oral symptom could signal a long-term deficiency, with effects that go far beyond the mouth

Vitamin B12 is synonymous with tiredness and brain fog, but few patients realise symptoms sometimes show up on the tongue.

Medical weight loss doctor Megan Horsham notes that one of the clearest signs of a long-standing deficiency is glossitis: a smooth, painful, reddened tongue that develops over years of low B12 levels.

But glossitis rarely appears in isolation, she explained. Long-term deficiency can also bring spinal cord degeneration, possible paralysis, bowel and bladder incontinence and even delusions.

In fact, the symptoms clearly illustrate just how far-reaching the role of vitamin B12 in the body actually is.

It begins first and foremost with some of the body’s most fundamental processes, the expert explained.

“Vitamin B12 plays a few important roles in the human body, including red blood cell formation, DNA synthesis, nerve functions, cognitive function and energy production,” she said.

Because the nutrient is so deeply embedded in these symptoms, its absence tends to ripple outward and affect everything from mental clarity to physical coordination.

In its infancy, a vitamin B12 deficiency appears to masquerade as something else entirely.

“The symptoms of B12 deficiency mimic the symptoms of anaemia,” Dr Horsham explained.

Light-headedness, dizziness, fatigue, headaches, pallor, palpitations and shortness of breath are some of the most common complaints from patients.

And because the symptoms overlap, the condition often goes unnoticed or is misattributed for long periods before more serious signs emerge.

Left unaddressed, the consequences can become considerably more serious, with Dr Horsham warning of muscle weakness, difficulty walking, and peripheral neuropathy - where the nerve endings become damaged.

Thankfully, B12 deficiency is relatively straightforward to test for and treat.

Those affected can make dietary changes, take supplements, or have an injection depending on severity and underlying cause.

But Dr Horsham warns that the telltale signs, like a sore tongue, unexplained fatigue and mental fog, are easy to dismiss as minor niggles, when in fact they may signal a deficiency that’s been building for years.