Am I at risk for developing vitamin and mineral deficiencies if I have Bariatric surgery?

An adjustable gastric band or a gastric sleeve operation are NOT likely to cause any vitamin or mineral deficiencies since the small intestine has not been reoriented in any way. It is still a good idea to take a multivitamin and calcium each day especially for women but it is not absolutely necessary if you chose to have either of these operations.
Also, it is very unlikely that a person that has a Roux en-Y gastric bypass will develop deficiencies IF they take a multivitamin each day and have yearly checkups with laboratory evaluation to check their vitamin and mineral levels. However it is very important that a gastric bypass patient is willing to take their vitamins and calcium every day.
The reason this is so important is that a Roux en-Y gastric bypass excludes the first part of the small intestine from the flow of nutrients and therefore the B vitamins need to be supplemented and levels checked periodically since htis is where the B vitamins are best absorbed. Otherwise vitamin B1 deficiency can cause numbness or memory loss and vitamin B12 and vitamin B6 could lead to anemia.
Also it is important that a calcium supplement be taken each day. This should be taken as calcium citrate (800mg / day) since calcium citrate is nearly 100% absorbed. Unfortunately calcium carbonate, the usual form of calcium supplement, is not absorbed well since a gastric bypass patient does not produce very much acid in the gastric pouch which is necessary to help make the calcium available to be absorbed. Of course, calcium is not absorbed well in the absence of adequate vitamin D. Although a gastric bypass is not likely to interfere with vitamin D absorption, persons of size often have vitamin D deficiency and they need vitamin D supplementation regardless if they have had surgery or not. This may be from not being out in the sun much or there may be other reasons we are not yet aware of. We check all of our patients for vitamin D deficiency when they first are seen even before their operation. If they have a low vitamin D level we will start them on Ergocalciferol, (the active form of vitamin D), at 50,000 units monthly or weekly depending on the severity of the deficiency. I believe a bone density study should be done every 2 years for postmenopausal women and women who have had a total hysterectomy and have had a gastric bypass operation. Osteoporosis can be avoided if a gastric bypass patient follows these directions.
Iron deficiency is unlikely except in menstruating women. If a woman has heavy periods it may be difficult for them to keep up with their iron needs. If they begin to be anemic we will check their iron stores by checking a Ferritin level and if this is found to be low we will start them on an iron supplement. This supplement should be Ferrous Fumarate or Ferrous Glucanate since the usual for of iron supplementation, Ferrous Sulfate, will not be absorbed well since like calcium carbonate it needs acid to make the iron available for absorption and since the new small gastric pouch makes very little acid, Ferrous Sulfate is likely to pass out in the stool without being absorbed. You any need to remind your family doctor about this since they are so used to writing for Ferrous Sulfate and may forget you need a different form of Iron. Occasionally iron supplementation is not enough so a patient may be referred to their gynecologist for further evaluation and hormone treatment or surgery such as an endometrial ablation or hysterectomy. Of course, a full work up for anemia may be in order in certain circumstances. Remember the years of obesity may place a patient at increased risk for colon polyps or colon cancer. Therefore, a colonoscopy may be in order. My patients are always pleased when I recommend that study!
Early in my bariatric surgery practice I checked for vitamin and obtained a blood count at 3 and 6 months after surgery. However, it seems that it take about a year to see any of these changes except in unusual circumstances. Therefore I usually wait for 1 year before I check these lab tests unless there is a good reason the check before.
I also check a vitamin A level yearly although like vitamin D a gastric bypass is unlikely to be the cause of vitamin A deficiency.
I should make a comment regarding another bariatric operation that has a much greater risk of vitamin and mineral deficiencies. that is the "duodenal switch" or bileopancreatic bypass. This operation leaves the patient with only about 2 feet of small intestine to be used to absorb nutrients. This often causes much more difficulty with maintaining appropriate vitamin levels including vitamins A, D, B1, B6, B12 and sometimes K. Although this operation is performed well and safely by several of my bariatric surgery colleagues, I personally feel this is a more radical operation than necessary for most patients and I have chosen not to perform these operations. If this is of interest to you I would suggest doing a Google search for "Duodenal Switch" and finding an experience bariatrics surgeon to do this operation for you. By the way, the surgeon that is moat associated with this operation is Dr. Douglas Hess from Bowling Green, Ohio. Dr. Hess trained at the Riverside Methodist Hospital where I am now the Director of Bariatric Surgery. Dr. Hess is now retired but he is a wonderful man and has helped many persons of size resolve their obesityand their obesity related medical problems.
The "take home" message is this: if you chose to have a gastric bypass operation, take a multivitamin and calcium citrate 800 mg each day and see your bariatric surgeon or a primary care provider that is comfortable following you for these matters YEARLY and you are very unlikely to have a significant vitamin or mineral deficiency. I hope this is helpful.
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