This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
Metabolic complications of subtotal gastrectomy with Billroth I or Billroth II reconstruction include: 
Select and explain. 
A. Anemia, B. Reactive hypoglycemia, C. Dumping syndrome, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Anemia develops in as many as 30% of patients within 15 years of surgery. The cause is multifactorial and includes malabsorption of iron, folate, and vitamin B 12. A metabolic bone disease occurs in as many as 33% of patients, is similar to osteomalacia, and is probably a result of malabsorption of calcium and vitamin D. Reactive hypoglycemia occurs with rapid gastric emptying, resulting in increased glucose absorption immediately after a meal. Initially there is hyperglycemia, leading to hyperinsulinemia and subsequent rapid glucose clearance and symptomatic hypoglycemia. Dumping syndrome varies from very mild symptoms to significantly disabling ones. The severe syndrome occurs in fewer than 5% of patients. Small, frequent, dry meals of low osmolality reduces symptoms and somatostatin analog has been of some clinical use.