A 2021 systematic review of 16 randomized controlled trials and 6,276 participants (Markun and colleagues, Effects of Vitamin B12 Supplementation on Cognitive Function, Depressive Symptoms, and Fatigue, Nutrients, 2021) found that B12 supplementation does not reliably reduce fatigue in people who are not deficient
AOD 9604 is safe and effective for both men and women, especially those over 30 who are noticing slowed metabolism, stubborn fat, or delayed recovery
"Trends in blood folate and vitamin B-12 concentrations in the United States, 1988 2004"
This is a classic example of its supportive, rather than primary-driver, role
A physician investigating unexplained hypercobalaminemia will typically order some combination of the following: Complete blood count (CBC) with differential to check for abnormal red blood cell, white blood cell, or platelet counts Liver function tests (ALT, AST, ALP, bilirubin, albumin) to assess liver health Kidney function tests (creatinine, BUN, estimated GFR) to evaluate renal clearance Peripheral blood smear if a myeloproliferative disorder is suspected Abdominal imaging (ultrasound or CT) if liver or abdominal pathology is a concern Cancer-specific markers or screenings if clinical suspicion warrants them The NIH Office of Dietary Supplements fact sheet notes that observational data from a Danish registry analysis of 757,185 people found the adjusted 1-year cancer risk was 1.74 to 4.72 times higher among those with B12 above 813 pg/mL compared to those in the normal range of 203 to 813 pg/mL
The packages are reasonable