Celiac disease is a digestive and autoimmune disorder that results in damage to the lining of the small intestine when foods with gluten are eaten. Gluten is a form of protein found in some grains. When foods containing gluten are consumed, the immune system forms antibodies to gluten, which then attack the intestinal lining. This causes inflammation in the intestines and damages the villi, the hair-like structures on the lining of the small intestine, which normally absorb nutrients provided from food. If the villi are damaged, nutrients are not absorbed properly and malnutrition may occur.

Symptoms of celiac disease include digestive problems (abdominal bloating, pain, gas, diarrhea, pale stools, and weight loss), iron deficiency anemia, and musculoskeletal problems (muscle cramps, joint and bone pain). Adopting a gluten-free diet is the primary treatment approach for celiac disease, however nutritional supplementation may also be necessary for malabsorption caused by damage to the intestines.