Additionally, chronic conditions such as HIV and tuberculosis have been implicated in B12 deficiency due to increased metabolic demand and altered absorption mechanisms ( The diagnosis of vitamin B12 deficiency typically relies on low total B12 levels and elevated concentrations of homocysteine (Hcy), as well as levels of transcobalamin-bound B12 (holoTC) and methylmalonic acid (MMA), which serve as functional indicators of cobalamin insufficiency ( Vitamin B12 requirements fluctuate throughout the life course, influenced by metabolic demand and physiological changes
Vitamin B12 (Methylcobalamin) This vitamin is an energy booster and among the most important of all the B vitamins
This higher occurrence stems from several age-related factors, including reduced gastric acid production (hypochlorhydria), pernicious anaemia (autoimmune destruction of intrinsic factor), and sometimes decreased dietary intake
doi:10.1089/acm.2005.11.909
SAM has been described as one of the few sentinel metabolites of the cell, with an estimated 1% of all eukaryotic proteins being SAM-dependent methyltransferases with diverse substrates 65,66