This information made me wonder about the supposed zinc test where you swish liquid zinc in your mouth and if you taste it right away you have good stores of zinc. If it tastes like water you are deficient. Any evidence base for that?

Chris Kresser:  Yeah, that’s called the zinc tally test and there’s not a lot of evidence, but there’s at least two studies that I saw, and this was a while back. I haven’t checked lately, so maybe it’s changed. There are two studies that looked at the zinc tally test, particularly in pregnancy and compared it to serum zinc testing and found that there was pretty good correlation between the two. But the problem without that as you know is that serum zinc testing itself is not really an accurate marker for zinc status. So yeah, you’re measuring one test of unknown accuracy against another test of known inaccuracy. It’s not really, doesn’t really tell you much, does it?