How long do patients need to take multivitamins after gastric bypass surgery?

I occasionally see patients who have stopped taking multi vitamins after gastric bypass surgery. These patients had their surgery several years ago. They think they can now eat everything and dont need to take vitamins.
From medical point of view, I believe that is dangerous. It is true that some patients can probably absorb enough vitamins from their diet a few years after surgery but it is not possible to predict who those patients are. Our bodies have reserves of vitamins so it takes weeks to months to develop vitamin deficiencies. However some of the vitamin deficiencies are irreversible and there is very little (if any) down side to taking multi vitamins on a regular basis. As a rule, gastric bypass patients need to take

Any brand name multi vitamin (twice the amount recommended on the label)
In addition
1500-2000 mg of calcium carbonate or 1000-1500 mg calcium citrate
500 microgram B12 and
325 mg ferrous sulfate
daily

A new feature

To all bariatric patients of Hamot Bariatric Surgery Center.
We are trying a new online communication tool for our bariatric center. When I receive an email about bariatric issues, I will post my replies to our blog page. I am hoping that other patients will be able to benefit from those responses.
Please feel free to give us your feedback about the ways to improve the site.
Thanks
Sincerely
Amjad Ali