The neurological manifestations of vitamin B12 deficiency are an SOS warning sign, because they indicate damage to the myelin. Think of your nerve system as a tangle of electrical wires. Each of these wires is wrapped by myelin, a protective layer guarding every cranial, spinal, and peripheral nerve fiber in your body. When the myelin gets stripped off, the brain’s neurons can’t transmit electrical signals properly.
Vitamin B12 helps form and maintain the myelin sheath. When there’s a prolonged B12 deficiency, the myelin starts to recede, and as a result, nerve damage occurs. This is why patients suffering from an untreated B12 deficiency eventually develop neurological signs and symptoms. Although progression is gradual, once neurological damage has been present for a while, it may not be reversible with treatment.
So, of all symptoms of B12 deficiency, what are specifically the neurological ones?
Let’s have a look.
Neurological Symptoms of B12 Deficiency
- ‘Pins and needles’, a sensation of uncomfortable tingling, usually felt in the tongue, hands, arms, thighs, or feet.
- Numbness, a loss of sensation or feeling in any part of the body.
- Rhythmical, involuntary shaking movements (tremors).
- Coordination and balance issues. Falling, or at least difficulty in walking or keeping yourself steady.
- Forgetfulness, memory loss, difficulty to recall words or names.
- Changes in taste and smell.
- Changes in vision, such as blurred vision, nystagmus, blindness, visual disturbances, and optic atrophy.
- Difficulty concentrating.
- Intellectual deterioration, dementia.
- Mood changes.
- Ringing or buzzing in the ears (tinnitus)
- Impaired pain perception.
- Confusion, dizziness, a sense of disorientation.
- Nocturnal leg cramps – painful, involuntary muscle contractions in your legs, usually occurring when you’re in bed.
- Speech problems (ataxia).
- Spinal nerve pain, commonly in the lower back and neck.
- Unexpected, abnormal reflexes.
- Sharp nerve shocks in the left or right side of the body.
- Any form of paralysis.
Is Recovery Possible?
How fast can you recover, and are B12 deficiency neurological symptoms reversible?
Yes, but we don’t fully know to what extent.
Right now researchers are still experimenting on rats, so any evidence relating to human physiology will be a few years in the future unfortunately. For now, we do know that methylcobalamin B12 promotes regeneration of the rat sciatic nerve:
Schwann cells (SCs) are constituents of the peripheral nervous system. The differentiation of SCs in injured peripheral nerves is critical for regeneration after injury. Methylcobalamin (MeCbl) is a vitamin B12 analog that is necessary for the maintenance of the peripheral nervous system. In this study, we estimated the effect of MeCbl on SCs. We showed that MeCbl downregulated the activity of Erk1/2 and promoted the expression of the myelin basic protein in SCs. In a dorsal root ganglion neuron-SC coculture system, myelination was promoted by MeCbl. In a focal demyelination rat model, MeCbl promoted remyelination and motor and sensory functional regeneration. MeCbl promoted the in vitro differentiation of SCs and in vivo myelination in a rat demyelination model and may be a novel therapy for several types of nervous disorders.Methylcobalamin promotes the differentiation of Schwann cells and remyelination in lysophosphatidylcholine-induced demyelination of the rat sciatic nerve
In humans, vitamin B12 can reduce cerebrospinal fluid to serum B12 ratio in demented men. Also, B12-B6-folate treatment improves blood-brain barrier function in patients with hyperhomocysteinemia and mild cognitive impairment:
None of the patients progressed into dementia during the treatment period. When treated with a vitamin B12-B6-folate combination, patients with mild cognitive impairment and hyperhomocysteinaemia appear to improve their blood-brain barrier function. They may also stabilise their cognitive status. Further investigations are warranted on the role of blood-brain barrier dysfunction in the pathogenesis of dementia.Vitamin B12-B6-folate treatment improves blood-brain barrier function in patients with hyperhomocysteinaemia and mild cognitive impairment
In our experience, damage to the myelin can get to a point where it’s no longer fully reversible. If you show any neurological symptoms of B12 deficiency, we recommend starting a B12 injection therapy right away. We recommend methyl B12 shots, because they show unique nerve-repairing properties, and are the best option if you suffer from nerve damage. At the very least, they will stop you from deteriorating further.
And please, don’t wait another day. B12 has no overdose or toxicity levels, so there really is no risk. Small neurological symptoms could easily progress to major nerve damage, putting you in a wheelchair for the rest of your life. Don’t wait.