After weight loss surgery you will need a vitamin supplement.
The doses you take will change with time and are different for each weight loss surgery (gastric band, gastric sleeve, RYGB, BPD).
The starting doses for some key vitamins are shown in this free pdf attachment.
These vitamins are discussed in a related article Vitamins: How much is too much?
You need other vitamins and minerals as well. I will cover these in a future article. Be sure to sign up for my newsletter to be first to read it.