High BAC levels can lead to severe impairment, loss of consciousness, alcohol poisoning, and even death
Some people use sublingual delivery (powder held under the tongue briefly before swallowing) but there's no strong evidence this meaningfully improves bioavailability for this compound class
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
These tissues can sometimes be slow to recover, particularly when blood flow is limited
