There are folks that supplement with 1000Mcg of Chromium 200 (usually diabetics under medical supervision)
It's fine - but if you feel "off", i.e increased sensitivity, mood swings, depression, etc - then this could be the culprit. It's one of the known (but rare) side effects.
Chromium-200 helps to increase insulin tolerance levels (slightly). In a PO shake, it's claimed to be helpful as these shakes can spike blood sugar levels and prematurely release insulin (which leads to increased adipose deposits). I haven't read any authoritative studies that has proven this ingredient is helpful or even needed in a PWO shake, but in theory I guess it could be.
If your a ectomorph, the supplement isn't needed at all as ecto's already have high tolerance levels - but again, 400Mcg shouldn't do anything "adverse". The reaction is only moderately detectable.
But always keep in mind that that word "supplement" means "in addition too", not "instead of" real food. ALL supplements require a good diet to be truly beneficial.