The most common clinically relevant micronutrient deficiencies following gastric bypass include thiamine, vitamin B12, vitamin D, iron, and copper. Reports of deficiencies in many other nutrients, some with severe clinical manifestations, are relatively sporadic. This review focuses on the main nutritional issues associated with bariatric procedures by examining some important clinical conditions that are caused by vitamin and micronutrient deficiencies, such as anaemia, osteoporosis, neurological disorders and malnutrition. We will also discuss the importance of careful preoperative evaluations and correction of pre-existing nutritional deficiencies, which are quite common in obese patients.
Finally, recommendations are presented for the prevention and treatment of nutritional deficiencies after bariatric surgery. The most common deficiencies caused by malabsorption of Roux-en-Y gastric bypass are iron, vitamin B12, folate, calcium and vitamin D. Other less common deficiencies that can occur after gastric bypass surgery include thiamine, zinc, copper, and vitamins A and K. Bariatric surgery can exacerbate or increase the risk of thiamine deficiency and cause beriberi, a condition caused by a lack of thiamine.
Postbariatric anaemia is most often due to iron deficiency, along with vitamin B12 deficiency as a secondary cause. The sleeve also reduces the risk of micronutrient deficiencies and associated complications related to Roux-en-Y gastric bypass and BPD procedures. The prevalence of vitamin B12 deficiency in patients scheduled for BS is reported in approximately 18% of patients. So why should patients also consider the intake and absorption of vitamins after gastric bypass surgery? Mineral deficiencies are more common after BPD and RYGB; however, the actual prevalence of these alterations cannot be accurately estimated, as most deficiencies may be present as early as surgery (see next paragraph).
A deficiency of vitamin B12 is rare among patients with gastric bands because they have full use of the stomach. Wah Yang, MD, surgical specialist and researcher at the First Affiliated Hospital of Jinan University in Guangdong, China, and colleagues reported that among 414 of 668 Chinese adults who underwent Roux-en-Y gastric bypass and sleeve gastrectomy procedures, 25.1% were deficient in thiamine (vitamin B), 21.4% deficient in vitamin C, and 19.7% had low levels of vitamin E. Malabsorption BPD with or without duodenal change includes this category of bariatric surgery. Gastric sleeve, although less invasive than gastric bypass procedures or BPD, can lead to a higher risk of folate deficiency.
Common Postoperative Micronutrient Deficiencies Bariatric procedures that involve techniques to reduce gastric capacity or redirect the intestines to the gastric pouch may result in micronutrient deficiencies. This chapter will provide the multidisciplinary bariatric team with a comprehensive review of micronutrient deficiencies before and after bariatric surgery. Questions to Ask Postoperative Surgery Patients When working with bariatric surgery patients, it is important to ask them questions during their post-op visit that can help determine if they are at risk of developing vitamin and mineral deficiencies. We examined some important clinical conditions that are caused by vitamin and micronutrient deficiencies, such as anaemia, osteoporosis and malnutrition.
The measurement of serum ferritin is the best diagnostic test for detecting iron deficiency, as it is a more specific and early indicator of the body's iron capacity and becomes abnormal before a decrease in serum iron concentration. .
