Anyone who's supplemented B vitamins probably knows that there's an unmistakable "colorimetric" way of telling when your kidneys are clearing excess riboflavin (vitamin B2). That neon yellow glow is hard to miss unless the lights are off.

Back when I was on the SAD, taking a typical multivitamin or two even sporadically led to a 'positive signal' within hours. Now that I'm eating LC/primal, doing a lot of walking, and taking either 3-4 "one-a-day" multivitamins or a big B-complex daily, I'm getting 400-600% RDA, but I never see any 'evidence' of excess/spillover.

Not that the government's so-called RDA means a damn thing, but it's far more B2 than I was getting back when I weighed 33% more than I do now. Makes me wonder if I'm really using it all, or what...and why. My diet already includes good natural B2 sources, but maybe I should take even more.

Anyone else here experience this 'phenomenon'?