Engaging Science Experiments: Exploring Water & Vitamin Absorption in the Human Body

Question
My sons friend has to do a science experiment, and he is doing it on the human body and the absorbtion of water, and vitamins in the body. Do you know of any science experiments that would be able to do for this experiment?

Thank You
Chris  

Answer
First, take a look at this site.  It's geared for youth and I find it fascinating!  Pictures and everything!
http://www.arches.uga.edu/~shayle/studio/6200/final/digestion.swf

This site is an actual teacher experiment set up, I think will do it for you 100%


http://www.ofcn.org/cyber.serv/academy/ace/misc/misc/misc001.html