Anemia

Anemia is a nutritional deficiency characterized by hemoglobin or red blood cell counts that are below normal levels. Men with red blood cell count levels of 13.5 grams and lower, and women with red blood cell count levels of 12 grams and lower are said to have anemia.

Gastric Bypass Surgery

Gastric bypass surgery is a type of bariatric or weight loss surgery, and is also the most common.  The procedure involves making a portion of the stomach into a small pouch, and thereafter attaching it to the small intestine, particularly in the distal segment, avoiding the duodenum and a part of the jejunum.

In short, gastric bypass surgery is gut manipulation, which naturally affects the absorption of nutrients into the body. This leads to the development of nutritional deficiencies, anemia being the most common.

Iron Deficiency

The nutrient iron is mostly found in red meat and vegetables. The duodenum and jejunum are largely responsible for effective iron absorption into the body, and thus the interference caused by gastric bypass surgery may cause iron deficiency.

Iron deficiency is thought to be the common cause of anemia in post-operative gastric bypass patients. However, not all anemia's in such patients are caused by iron deficiency.

Vitamin B-12 Deficiency

One study showed that 29% of post-operative gastric bypass patients observed suffered from below normal levels of vitamin B-12.

Vitamin B-12, which is found mostly in meat and dairy, is another nutrient which, when deprived of, can cause anemia. Gastric bypass patients have the tendency to suffer from vitamin B-12 deficiency because the breakdown of vitamin B12 is impaired with the bypass of the duodenum.