Shimizu, K
Using a serum B12 test in a patient on B12 injections to confirm B12 levels are replete is incorrect, but it happens
Acknowledgements Work discussed in this Review was supported by a Wellcome Trust Senior Investigator Award (095531), the Knut and Alice Wallenberg Foundation, the Swedish Research Council, the Hartwell Foundation for Biomedical Research (201500731), the Juvenile Diabetes Research Foundation (CDA-2-2013-54) and the US NIH (DK110276)
The copper ion itself plays a specific structural and enzymatic role in this process, covered in more depth in copper in biology: why the ion matters as much as the peptide
Current practice in the use of MEGA-PRESS spectroscopy for the detection of GABA
Oral supplements may suffice for general support or mild deficiencies, while injections are better for those seeking quicker results, dealing with digestive issues, or needing targeted doses for performance enhancement