Vitamin Deficiency With Weight Loss Surgery

Bariatric surgery, or weight-loss surgery, which reduces the size of your stomach so that you absorb less food, literally saves the lives of many obese people. Decreasing the area of stomach and intestine available for food absorption does come at a price, however. Many people become vitamin deficient after bariatric surgery and require vitamin supplementation to stay healthy.

Surgery Types

There are several different types of weight-loss surgery, with differing impacts on vitamin absorption. Lap-band surgery, which places an adjustable band around the stomach to decrease its size, can cause vitamin deficiencies, but this occurs less frequently than with the more complex surgeries. Gastric bypass, duodenal switch and bileopancreatic diversion surgeries, which bypass sections of the intestines and work by malabsorption, cause more severe deficiencies.

Causes

Gastric bypass surgeries divert food past the part of the small intestine, which absorbs most vitamins. Vitamin deficiencies can also result from vomiting after surgery. Many obese patients start out with vitamin deficiencies even before surgery; John Baker, M.D. president of the American Society for Metabolic and Bariatric Surgery reports that around 60 percent of his patients have vitamin B-12 deficiencies and around 20 percent have iron deficiencies even before surgery.

Deficiencies

The most common vitamin deficiencies after weight-loss surgery include the B-complex vitamins: B-9, also called folate, B-1, also known as thiamine and B-12, also called cobalamin. B-12 deficiency affects as many as 30 percent of people who undergo Roux-en-Y gastric bypass, or RYGB, according to the Baylor College of Medicine, while as many as 42 percent experience folate deficiency. Deficiencies of the fat-soluble vitamins A, D, E and K also commonly occur. Iron, although not a vitamin, often is deficient after weight-loss surgery as well, affecting between 35 and 50 percent of patients who have RYBG, according to Baylor College.

Treatments

While most bariatric surgeons recommend taking a multivitamin after weight-loss surgery, multivitamins don't contain adequate amounts of some nutrients. B-12 supplementation in the form of monthly injections or taken daily sublingually, under the tongue, can help prevent B-12 deficiency. Your doctor may also order other additional supplements depending on your blood levels. Follow up at six and 12 months post-surgery with your doctor so blood tests can assess your nutritional levels, the National Anemia Action Council advises.

Complications

Vitamin deficiencies can cause a number of potentially serious complications, including vision loss from vitamin A and E deficiency, bone loss from calcium and vitamin D deficiency, peripheral neuropathy and Wernicke's syndrome, which causes confusion and clouded mental status, from B-complex deficiencies and a low red blood count from iron deficiency.