B12 has many functions in our body, so unfortunately a deficiency will give rise to a wide variety of symptoms, like brain fog, memory problems, cognitive impairment, insomnia, headaches, especially migraine, behavioural changes, learning problems, nominal aphasia, mood swings, irritability, depression, anxiety, hallucinations, delusions, psychosis, peripheral paraesthesia (pins and needles), numbness, neuropathic pains, poor balance, reduced vibration sense or proprioception (joint position sense), tinnitus, ataxia, taste impairment, sometimes myelopathy, fatigue, anaemia (either with larger red blood cells, or with normal size of the red blood cells when there is also iron deficiency), other reduction in blood cells, abdominal complaints, malabsorption, failure to thrive, weight loss, diarrhoea, hyperpigmentation, glossitis, (aphthous) stomatitis, infertility, urinary tract infections, joint and muscle pain, muscle weakness, spasticity, seizures, cardiomyopathy, urinary and/or faecal incontinence, postural hypotension/dizziness, erectile dysfunction, to name a few

Aids in red blood cell production and immune health
Under-the-Tongue Tablets or Sprays : Sublingual B12 dissolves under the tongue, offering a convenient option for those with absorption issues or difficulty swallowing pills, and research supports its effectiveness[22]
This helps prevent muscle loss that often accompanies aging