Presurgical Phase of WLS

Hello I am currently doing the presurgical phase of the WLS whi*****ludes the practice diet. I am wondering about vitamins and protein intake. I have bought the Centrum chewables, the B-Complex liquid and I still need to find the Calcium Citrate chewables or liquid. Have any of you found these in one easy to intake product? I am also trying to figure out how to get all of the water in when not able to drink with meals and keep it 1/2 hour from meals. Any suggestions? I am going through the Wish Center program. Thank you Lori