A mislabeled or substandard formulation can introduce variables that are nearly impossible to identify after the fact
Deficiency In healthy adults, overt vitamin B 12 deficiency is uncommon, mainly because total body stores can exceed 2,500 g, daily turnover is slow, and dietary intake of only 2.4 g/day is sufficient to maintain adequate vitamin B 12 status (see The RDA) (4)
Journal of Education and Health Promotion, 7 , 36
10.1002/1521-3765(20010803)7:15 3.0.CO;2-7 Chemistry 105 KiziltepeT.HideshimaT.IshitsukaK.OcioE
This segment is the most conserved region within the 64-aa sequence that shows homology to corresponding regions in Mto1p, Pcp1p, Cnn, Aspergillus nidulans ApsB, human myomegalin/phosphodiesterase 4D-interacting protein (PDE4DIP), and several unknown sequences of other species (Sawin et al