doi: .10.1210/jc.2017-01411 [PMC free article: PMC5718699] [PubMed: 29029190] [CrossRef] 133
I still have a ton here, so Ill keep experimenting, but I wanted to share my N=1
Comorbidities like type 2 diabetes and metabolic syndrome a cluster of metabolic disorders that includes obesity, dyslipidemia, hypertension, and insulin resistance, leading to chronic systemic inflammation
This could interfere more intensively with Vit B12 intra-cellular metabolism nullifying the "physiological metabolic rest" of these components (Merola et al

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

In the long term, an unchecked vitamin B12 deficiency can lead to permanent nerve damage, which is why its important to catch it early