Unfortunately, plasma levels of many elements don't tell you if you aren't deficient already. For many tissue deficiencies you need to do e.g. radioactive scans

Unfortunately, plasma levels of many elements don't tell you if you aren't deficient already. For many tissue deficiencies you need to do e.g. radioactive scans which nobody will do for you. You can be vitamin deficient, potassium deficient etc. and plasma deficiency will show up only when you are really at the edge of something chronic or death. See e.g.: https://www.mayoclinicproceedings.org/article/S0025-6196(18)30227-1/fulltext https://www.mayoclinicproceedings.org/article/S0025-6196(18)...