FDA, on February 3, 2012 Healthy People Co
Up to 20% of people over 60 may become deficient according to UCLA Health (2022), and the National Institutes of Health estimates that 10 to 30% of older adults cannot absorb naturally occurring vitamin B12 from food
As far as I know (I'm not medically trained or a scientist) overdosing B12 is unlikely as excess passes out in urine
They manufacture in FDA-registered, GMP-certified facilities and claim 99%+ purity testing
Searching by complication first: Neuropathy, diabetic redirects to Diabetes, diabetic / with / neurological complications. Retinopathy, diabetic redirects to Diabetes, diabetic / with / ophthalmic complications. Insulin dependence lookup: Z79.4 is found under Long-term (current) drug therapy / insulin. This code is critical for risk adjustment documentation
Various booster shots are available depending on your symptoms and needs