Open questions include tissue-selective delivery, chronic dosing effects on one-carbon metabolism, and interactions with NAD precursor strategies [14,8,9]
Evidence ranges from international approvals and randomized trials to preclinical and community-use data
A deficiency of B12 can lead to anemia and neurological abnormalities, but supplementation is a safe and cost-effective method of improving quality of life even when vitamin B12 levels are unknown
For patients with adequate food intake and no concerning symptoms, routine laboratory monitoring may not be necessary
If neurological symptoms are present (such as paraesthesia, ataxia, cognitive changes, or visual disturbances), more intensive treatment is required