Although the short-term effects of weight-loss surgery are well understood, there are still questions to be answered about the long-term effects on nutrition and body systems. Nutritional deficiencies that occur over the course of many years will need to be studied. Over time, you will need periodic checks for anemia (low red blood cell count) and Vitamin B1, B12, Vitamin D, folate, and iron levels. Follow-up tests will initially be conducted every three to six months or as needed, and then annually. It is very important to keep all of your follow-up appointments, even if you are feeling well or if you need additional encouragement to stay on track.