I'm not sure if this should be in a sciencey place or chat, but I'll presume it's fine here.
I decided to buy some beetroot juice yesterday, I erm had it all, 750ml. This morning I went for a dump, and well, it was all dark purple, this is understandable, but why was my pee pretty much the same colour as normal? Why would it just effect my solids but not my liquids?
Usually affects my pee too. but it can be quite subtle.
probably just that only a small % of the colouring is absorbed from the gut. Obviously, only what is absorbed from the gut can make its way to your urine. The majority remains in the gut giving the crap a darker colour.
Also depends on how hydrated you are (if you're dehydrated your urine would be darker yellow anyway so makes colour change less obvious, if you're overhydrated then the other fluids you've been drinking [eg water] dilutes the purple so may just be very light pink)
and whether you drank it all at once (i.e you pee it out over several "portions" [for want of a better word], but probably only crap once a day!).
(Original post by Revd. Mike)
Beta-carotene is orange...
Granted, the red colour of the OP's urine is actually because: 'Pigments called betacyanins give beetroots their red colour. These are acid/base indicators that are structurally unstable at extremes of pH, and have optical stability at pH 4 to 5. Red colour in urine, therefore, is dependent on urine pH. For the urine to be red, unchanged beetroot pigments have to be absorbed, and excreted. Though almost all of us have beetroot pigments in our urine after eating beetroot, the colour is too faint to see with the naked eye.'
However, beetroot leaves are very rich in beta-carotene, which is probably why I got confused!
The reason your stool turned red after ingesting 750ml (equal to 3 beetroots) of beetroot juice is the large fiber content. The reason your urine didn't change is that you have a normal balance of iron in your diet. The estimate is 15% of the population has normal levels of in iron. However, when urine does turn red is known as Beeturia. It occurs in 66-80% of individuals with untreated iron deficiency.