In past with UC when I got anemic, I stuck to wheatgrass juice and it helped alot. I continued it till the takedown. Now also everytime I visit my surgeon the supplement he recommends me is iron capsules. I told him that I don't feel like my iron levels are low anymore to which his reply is always you won't know until its late so keep taking a tablet a day. As for the dehydration or loss of electrolytes part I eat upto 5 bananas a day on avg. , I have made it my preworkout meal, so potassium is always in check. Rest I drink plenty of water , 1 litre first think in the morning and 1 litre 1 hour after dinner. I do this so that even if I forget to drink enough during the day it keeps in check my overall fluid intake. At the gym I carry a large bottle of plain water , I've noticed that I get dehydrated much faster than all my buddies around.