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Supplementation after Bariatric Surgery


Vitamin and mineral supplementation after bariatric surgery is almost universally needed in the short-term – (within about 6 months after surgery), but depending on the procedure it may or may not be needed in the long-term. Immediately after bariatric surgery, patients will be eating much less and consuming far fewer calories. Caloric intake may be reduced by as much as 750-1250 per day in the case of gastric bypass patients. In fact, they will be on a clear liquid diet for about two weeks and then on a liquid diet for a few more weeks. At a certain point, determined by their surgeon, patients will start eating solid foods. However, because most procedures restrict the amount of food that can be consumed, supplementation in the short-term is needed to avoid nutritional deficiencies.

Typical nutritional deficiencies include: Vitamin B12 and other B vitamins, Iron, Calcium, Vitamin D and various other micro-nutrients. Protein deficiencies may also occur, which can in some cases contribute to hair loss. While we do know that supplementation is necessary, each patient is unique and the exact degree of supplementation will be determined after surgery with regular follow-up.

Longer-term, gastric bypass patients are more likely to need supplementation for the rest of their lives. The gastric bypass procedure reroutes the small intestine creating malabsorption which means that fewer calories and nutrients are being absorbed into the bloodstream through the intestinal tract. As a result, generally no matter how nutritionally dense the food a patient consumes is, it likely will not be enough to get the nutritional value that they need to stay healthy. In this case, long-term supplementation fills the void.

Gastric sleeve and gastric banding patients – since there’s no rerouting of the intestine – will likely not have to take as many nutritional supplements over the long term, especially if they follow their prescribed diet. Blood levels should and will be checked periodically to ensure that the patient has no serious nutritional deficiencies. It is worth noting however that this is a general guide and does not necessarily apply to every patient. Each patient will recover in a different manner and will respond to weight loss surgery in a unique way. The surgeon will be able to determine the course of supplementation based on the circumstances of the patient’s recovery. In the end, it is important for patient be healthy after surgery – that is the point of the procedure. Therefore, supplementation may be necessary in the event that the body is not receiving the proper nutrients.

In order to reduce the need for significant supplementation for the rest of their lives, patients should follow their dietitian’s and surgeon’s nutritional intake guidelines very closely. These plans are created for the purpose of balancing safe and consistent weight loss with receiving the proper nutrition and vitamin levels that the body needs. Please consult our office or your nutritionist to find out the likelihood of needing supplementation and what you can do with your diet, exercise and lifestyle to minimize the need for additional supplementation.

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