If you want a "true" reading... you have to stop some of them.

B12 stop at least 5 days.
B6 stop at least 5 days.

Vit D Since many do not show fast gains with this it may not
affect results much.

I'd stop the magnesium too.

Traditional blood work from doctors measures serum levels.

Better tests are available, but many doctors don't use them.
Acu-cell is one example.

this website explains it:
http://www.acu-cell.com/

Basically serum levels don't reflect what is going on much in the body. Very low or very high show either deficiency or over use or some failure in the body to activate (as in B6).

For example on PubMed are many papers reporting "normal" magnesium levels in patients who then get supplemental treatment for migraine, with extra, who respond. At so called normal levels they have migraine (indicating a need).