Since bariatric surgery bypasses the sites where vitamins, minerals, and trace metals are absorbed, this can clearly lead to deficiencies of certain nutrients. This article is about what the three surgeries do to five essential nutrients.
“Biliopancreatic Diversion” (BPD) surgery commonly causes deficiencies in vitamin B12, folate and iron. It less commonly does the same for vitamin D and calcium.
“Short Limb Roux-en-y Gastric Bypass” (RYGB) surgery commonly causes deficiencies in vitamin B12 and iron. It less commonly does the same for vitamin D, folate and calcium.
“Laparoscopic Adjustable Gastric Banding” surgery is less risky for causing deficiencies. Iron and folate can be victims, and in rare cases the levels of vitamin D, B12 and calcium can be reduced.
These deficiencies may develop slowly, and aren’t diagnosed until many years after surgery. For that reason, it’s prudent to take supplements right after bariatric surgery. Plus, have your doctor evaluate your nutrient levels at each annual physical. On the iron front, this deficiency is common in this surgery (especially in middle-aged women). In fact, nearly half of RYGB patients developed iron deficiency within four years, according to a 2006 study.
After RYGB, vitamin B12 deficiency may occur in seven of 10 patients. People who can tolerate meat are less likely to suffer this deficiency, as well as folate and iron deficiencies, compared to those who cannot tolerate meat. Still, taking B12 supplements can correct this deficiency in up to 81% of patients.
Before surgery, obese individuals may be calcium- and vitamin-D-deficient due to lack of exercise and high body fat. The surgery unmasks this problem, so it’s out in the open. In a study that followed 116 morbidly obese young women undergoing BPD, 76% had vitamin-D insufficiency before surgery — and 91% had it five years later. Low levels of this nutrient are linked to cancer, diabetes, rheumatoid arthritis, hypertension, and vascular disease. Clearly a problem. It’s essential to have your vitamin-D status checked every year after bariatric surgery.
Less common vitamins or minerals deficiencies have been reported, including those of vitamin K, potassium, magnesium, zinc, and copper.