Vitamin B12

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Vitamin B12 is critical for the functioning of the brain and nervous
system and for the formation of blood. It affects metabolism in every
cell in the body and is directly involved in energy production.

• Low B12 can cause
• pernicious anemia
• blood cells that are too large
• weak muscles; inflammation
• neurologic symptoms such as numbness in hands and feet
• blurred vision under stress
• impaired reflexes
• gait disturbances, such as difficulty walking a straight line
• psychiatric symptoms such as irritability, depression, confusion,
memory disturbances
• symptoms of anemia including tiredness, shortness of breath,
labored breathing
• impotence
• incontinence
• white patches of skin
• hair loss

• Neurological symptoms from low vitamin B12 may appear before the
B12 is low enough long enough for blood abnormalities to develop

• B12 deficiency in the elderly, commonly occurring due to digestive
issues and poor diet, can cause symptoms mimicking Alzheimer's

• Low B12 causes include
• lack of intrinsic factor
• smoking
• inadequate nutrition
• inadequate stomach acid
• high alcohol consumption
• significant stress
• stomach surgery

• Medications that may lower B12 include
• antacids
• proton pump inhibitors
• omeprazole
• metformin
• many antidepressants

• Low B12 is common in individuals with
• gastrointestinal disease
• any autoimmune condition
• narcolepsy
• hypothyroidism
• rheumatoid arthritis
• vegans/vegetarians

B12 test results discussed here
Supplementing B12 discussed here
Methylation and MTHFR mutation discussed here