You'll probably get more specific answers on the RNY board, but I'm sure some of the post-ops will be along to help. I was evaluated for RNY, though I decided to have another surgery. In that program we were told 2 comprehensive multi-vites a day (not Flintstones, think Centrum Forte or Centrum 50+ which has complete mineral support as well), plus calcium citrate (not carbonate) with vitamin D and magnesium and sublingual B12. Also, if you still menstruate you will likely need iron as well, go by your labs. The post-op eating plan was 2 weeks full fluids, 2 weeks pureed foods, 2 weeks soft foods and then regular diet for life always focusing on protein. Protein goal is a minimum of 80g per day with protein supplements (particularly whey protein) encouraged to meet goal. We were also told a minimum of 64oz of sugar free, caffeine free liquids a day, which is about what you're getting. As for exercise, we were told just to wait 6 weeks before doing anything intense or lifting anything over 15lbs.