Re: If you eat a lot of carrots will your skin turn orange?

I have asked my friend who is a doctor, and he said that his patient once complained that her urine turned orange after she ate 50 carrots a day for a few days. She had started a unrecommended diet. For urine to turn orange the carotene would have to be absorbed into the blood stream and then be filtered by the kidneys into the urine. This seems plausible, since all nutrients are absorbed into the blood stream. Carotene is the molecule that makes carrots orange. It is a large, hydrophobic molecule. Its formula is C40 H56. For skin to turn orange you there would have to be more carotene in the bloodstream than the kidneys could filter out. Then this carotene would have to diffuse out of the blood stream into the skin.

First, it is not healthy to have so much of something in the bloodstream. Kidneys depend on the relative concentrations of molecules (mostly salt) to filter the blood. Adding too much of one thing could ruin the balance.

Second, I think carotene, being so hydrophobic could move through membranes, but it would be a slow process, because carotene is so large. It could, though, Second, I think carotene, being so hydrophobic could move through membranes,but it would be a slow process, because carotene is so large. It could, though,possibly move into the skin from the blood vessles.

I am afraid I have not really answered your question, though I have re-phrased it. I hope you can ask the re-phrased question to someone with perhaps more clinical experience, like a family doctor.