Nat Med 31 , 819828 (2025)
Common B12 Deficiency Signs and Symptoms (that occur with sub-clinical deficiencies): Numbness Tingling, pins and needles Weakness, dizziness High homocysteine, low methionine Megaloblastic macrocytic anaemia Mild or moderate leukopenia (low white blood cells) Mild or moderate thrombocytopenia (low platelets) Enlarged red blood cells (macrocytosis) Abnormal white cell (neutrophils) Chronic fatigue or tiredness Overall weakness or lethargy General Signs and Symptoms: Ataxia, (unsteady walking) Paresthesia (prickling sensation) and weakness in peripheral nerves Confusion Infertility Vision loss Leg pains Shortness of breath Loss of appetite/weight loss Epigastric pain Osteoporosis Increased susceptibility to infection Failure to thrive in infants Vitiligo Premature greying of hair Burning feet Mental Changes Depression (including postpartum depression) Irritability Apathy Psychosis Sleepiness Suspiciousness (paranoia) Personality changes Memory loss Dementia, intellectual deterioration Hallucinations Violent behaviour In children, developmental delay and/or autistic behaviour Neurological signs and symptoms Abnormal sensations ie: pain, tingling, numbness of legs, arms, trunk Diminished sense of touch, pain and/or temperature Loss of position sense (awareness of body position) Weakness of limbs Clumsiness Tremor Symptoms mimicking Parkinsons disease or MS Spasticity of muscles Incontinence (urine or stool) Paralysis Vision changes Damage to the optic nerve neuritis, inflammation, atrophy Vascular Problems Transient ischemic attacks (TIAs) Cerebral vascular accident Coronary artery disease Myocardial infarction Congestive heart failure Palpitations Orthostatic hypotension Deep vein thrombosis Pulmonary embolism Pathology testing options for B12: Serum B12 (not that reliable) Methylmalonic acid (MMA) Homocysteine Holotranscobalamin (holoTC) If a severe deficiency is present: Serum B12 is low MMA is elevated Homocysteine is elevated As B12 is imperative to a healthy methylation cycle, regularly testing your B12 levels and ensuring you are consuming B12 rich foods are fantastic ways to maintain optimal levels
It is used with other drugs such as hydroxychloroquine (Plaquenil), steroids, and mycophenolate mofetil (CellCept)
Want to see the human trials and data behind evidence-backed options
