The Effects Of Bariatric Surgery & Nutritional Deficiencies

Bariatric surgery is becoming a common treatment option for the severely overweight or obese population. Several types of bariatric surgery procedures are available, but they all restrict food intake or limit absorption through surgical alterations of the digestive system. However, this disrupts normal nutrient absorption and food intake, which can lead to a variety of nutritional deficiencies.

Vitamin B12 and Folate

A primary concern after bariatric surgery is vitamin B12 and folate deficiencies. Vitamin B12 deficiency is the most common nutritional deficiency, with up to 30 percent of patients deficient a year after surgery, according to an article in the October 2009 issue of "Southern Medical Journal." The primary source of vitamin B12 is red meats, which are generally not tolerated well after surgery, and the enzymes needed to separate the proteins from the meat for absorption are inadequate post-surgery. A protein called intrinsic factor is required for the absorption of vitamin B12 and may be deficient after surgery. Folate deficiency is much less common after bariatric surgery, but vitamin B12 is required to convert folate to its active form. Vitamin B12 deficiencies indirectly lead to folate deficiencies. Multivitamins generally do not provide sufficient amount of vitamin B12 and folate. Additional supplementation is generally recommended. Monthly injections of vitamin B12 may also be recommended to prevent deficiencies.

Calcium and Vitamin D

Calcium and vitamin D are two important nutrients for healthy bones and teeth, but they also support many other bodily processes. Vitamin D is required by the body to absorb calcium, and vitamin D deficiency is common following surgery but is also common in patients before surgery. Dietary restrictions and surgical alteration of the digestive system limit the amount and efficiency of calcium and vitamin D absorption in the small intestines. Osteoporosis, bone fractures and other bone abnormalities are a major concern of calcium and vitamin D deficiencies. Multivitamins generally do not provide sufficient amounts of vitamin D and calcium and so additional supplementation is recommended, according to Western Pennsylvania Hospital.

Iron Deficiency

Iron deficiency is common after bariatric surgery and is the primary cause of anemia, or low red blood cell levels, after surgery, according to the Consumer Guide to Bariatric Surgery. Reasons for iron deficiencies include limited stomach acid production, which is required to convert dietary iron to a more absorbable form, reduced meat intake and bypass of the area of the intestines that maximally absorbs iron, according to an article by Jacqueline Alvarez-Leite in the September 2004 issue of "Current Opinion in Clinical Nutrition and Metabolic Care." Iron supplements are recommended following surgery, but they should not be taken within two hours of calcium supplements because they interfere with the absorption of each other.

Protein Deficiencies

Adequate protein intake after bariatric surgery is crucial because it not only is required by the body to function properly but also speeds the healing process. Malabsorption, reduced dietary intake and limited meat and dairy consumption may all contribute to protein deficiencies. Liquid protein supplements are generally recommended the first few weeks after bariatric surgery, but over time individuals should get most of their protein from dietary sources. It is important to note that protein from animals is a complete protein source, meaning it contains all essential amino acids, and plant-based protein is an incomplete source of protein, even though both should be included in a healthy eating plan, according to Western Pennsylvania Hospital.