The vitamin requirements will vary by the type of surgery. Sleeve patients require the least. Duodenal Switch patients have the most. And RNY gastric bypass patients are in-between.
After RNY surgery, you are required to take many vitamins for the rest of your life. This is because you body no longer synthesizes vitamins from food. That part of your stomach has been cut away, so this daily requirement is extremely important. Vitamin chemistry is important for absorption. Calcium supplements should be calcium citrate. There are also different chemistries of B12. I use the sublingual B12 and was told to use methylcobalamin. You cannot use a time-release version of B12. According to my nutritionist,, if you are taking iron supplements, it must be ferrous sulfate for the best absorption. Gummy vitamins are not absorbed properly and should be avoided.
It is important to put a 2 hour separation between the vitamins that contain iron and those that contain calcium. So in my case I found that what works best for me is to take the iron supplements just before bedtime. I put my vitamins in a weekly pill container. I have one container for the morning and one for the night. And I use a very small glass finger bowl for my calcium supplements. I put my calciums in the bowl in the morning and take them throughout the day, a couple every two hours. If I am up and about I put my calciums in a ziplock bag and carry them with me.