I'll try to answer your question to the best of my ability but there are others here that have way better information on supplements that we should be taking piost bypass, look up Pam T her profile has a lot of good information in it.
You should take a multi-vitamin, most people say to take two a day in fact because of what we malabsorp, personally I take one a day, but keep telling myself I'm going to start taking two throughout the day, it just hasn't happened yet.
Around 2000mg of calcium (I hope this is the right number, it's what I get in), taken in doses of no more than 500mg at a time because that is all you will absorb at once.
Iron supplement (I have a prescription so I'm not sure how much you should be getting, this is a hard one for me to get in because it causes severe constipation in me even though I've tried several different types and several different remedies to no avail), it is best to take iron with Vitamin C as it helps it to absorb.
Vitamin B12...sublingual, not in a pill that you swallow...I take 1000mcg a day...
I also take Vitamin D in dry form, got it from Vitalady and I take 10000iu's about 5 times a week with one of my doses of calcium.
Many people also take a b complex vitamin, but I'm lucky to get all those others in so I rarely remember to take one of those...also don't take calcium and iron at the same time, they hinder absorption of each other.
Good luck, I agree that it's hard to remember to get all the vitamins in when you have to split them up in so many doses. Some people set reminders on their cell phones so that they can remember to take them every couple of hours and get them all in in a day. WTG on your weight loss, I've lost 88.4 pounds since surgery and have about 35 to go to my first goal and 45 to go to my ideal goal.
~Melody~ 5'6" Tall, 42 years old