This is a common side effect that occurs after gastric bypass surgery. Because the procedure is restrictive and malabsorptive in nature, gastric bypass patients will experience nutritional deficiencies which will affect how the body functions. Nutritional supplements must be taken post-op in order to feel 100%.
This also includes vitamins such as B12, iron and calcium. Nearly half of all gastric bypass surgery patients develop anemia. Your surgeon will provide you a detailed list of nutritional and vitamin supplements that should be taken daily and/or regularly for optimal health.