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 assessments 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. In general, the high prevalence of preoperative nutritional deficiencies in bariatric candidates supports the need for careful preoperative assessment of nutritional status, to adequately assess and correct pre-existing deficits.
The main site of absorption of vitamin B12 is the terminal ileum. The storage capacity of vitamin B12 in the body is quite large; however, vitamin B12 deficiency can cause hematological and neurological symptoms. In particular, macrocytic anemia after bariatric surgery may indicate a deficiency of vitamin B12.Vitamin B12 deficiency was prevalent in 14% of the study population and decreased significantly over time due to intramuscular administration of vitamin B12 every 3 months, especially in RYGB. Many in the medical community believe that macronutrients are poorly absorbed after gastric bypass surgery, as is the case with BPD or BPD with the duodenal exchange procedure, while others say this is not the case.
Primarily, research shows that micronutrients are poorly absorbed after gastric bypass surgery, leading to micronutrient deficiencies in patients. Bariatric surgery, and in particular gastric bypass, is an increasingly used and successful approach for the long-term treatment of obesity and the improvement of comorbidities. Nutrient deficiencies after surgery are common and have multiple causes. Preoperative factors include obesity, which appears to be associated with the risk of several nutrient deficiencies and preoperative weight loss.
In the postoperative period, reduced food intake, suboptimal dietary quality, impaired digestion and absorption, and lack of adherence to supplementation regimens contribute to the risk of deficiency. 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. Diet and multivitamin use are unlikely to prevent deficiency consistently, so supplementation with additional specific nutrients is often needed.
Although optimal supplement regimens have not yet been defined, most micronutrient deficiencies following gastric bypass can currently be prevented or treated with adequate supplementation. We also discuss the importance of careful preoperative assessments and correction of pre-existing nutritional deficiencies, and present current recommendations for adequate long-term biochemical and nutritional monitoring. Recently, the American Association of Clinical Endocrinologists released updated guidelines for postoperative nutritional and metabolic support of patients after bariatric surgery in collaboration with multiple societies. Before starting treatment with bisphosphonates, vitamin D deficiency should be completely corrected to avoid severe hypocalcemia, hypophosphatemia and osteomalacia.
This review focuses on some nutritional consequences that may occur in bariatric patients that could hinder the clinical benefits of this therapeutic option. Iron deficiency in obese patients is probably related to the negative impact that chronic inflammation has on iron homeostasis. Symptoms of iron deficiency include a constant craving for ice (pagophagia); a desire and consumption of non-food materials such as paper, earth, clay, corn starch or paint; paleness and increased shortness of breath with new onset deficiency (etiology unknown); dark circles under the eyes; lethargy; and nails with impaired breathing form (koilonyquia). Folic acid deficiency is a possible complication of bariatric procedures that can contribute to anemia.
Nutritional complications associated with bariatric surgery can be prevented through lifelong nutritional monitoring with the administration of multivitamin and mineral supplements according to the patient's needs. Protein deficiency is less common in patients who have undergone gastric bypass, sleeve and adjustable gastric band procedures; however, it is a concern in those who have undergone BPD with or without duodenal change. However, numbness that worsens in patients with diabetes could be a sign of vitamin B12, thiamine, or copper deficiency, depending on the area of numbness. Questions to Ask Postoperative Surgery Patients When working with bariatric surgery patients, it's 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.
However, many of these complications can be prevented with regular follow-ups, routine micronutrient screenings, and nutritional supplements when a deficiency is identified. After gastric bypass surgery, ingested food and enzymes are mixed only in the small area of the common limb, which compromises the absorption of certain nutrients. Long-term follow-up visits should include screening for micronutrient deficiencies, bone health, and monitoring of nutrition-related diseases. Need for nutritional guidelines With the increasing prevalence of bariatric surgery, there is an increased need for evidence-based nutritional guidelines.