Complications of celiac disease

Malnutrition
The biggest danger of untreated celiac disease is malabsorption which in turn can lead to malnutrition. This occurs in spite of what appears to be an adequate diet. Malabsorption can lead to a deficiency in vitamins A, B-12, D, E and K, and folate, resulting in anemia and weight loss. Malnutrition can cause stunted growth in children and delay their development.

Loss of calcium and bone density
The continued loss of fat in the stool may also cause an excessive loss in calcium and vitamin D. This could be very dangerous because it may result in a bone disorder called osteomalacia, a softening of the bone also known as rickets in children, and loss of bone density. It is also proven that lack of calcium absorption can lead to a certain type of kidney stone.

Lactose intolerance
If the intestine has already been damaged by the gluten consumption, foods that don't contain gluten also may cause abdominal pain and diarrhea. Great majority of people with celiac disease aren't able to tolerate milk sugar found in dairy products and this condition is called lactose intolerance. If this is the case, you need to limit food and beverages containing lactose as well as those containing gluten. Once your intestine has healed, you may be able to tolerate dairy products again. 

Cancer
People with celiac disease who don't maintain a gluten-free diet also have a greater chance of getting one of several forms of cancer. The most common forms are intestinal lymphoma and bowel cancer.

Neurological complications
Celiac disease has also been associated with disorders of the nervous system, including epilepsy and nerve damage although this is very rare.

Treatment of celiac disease

Unfortunately there is no cure for celiac disease but the patients can effectively manage their disease through dietary changes. Once gluten is removed from diet, inflammation in small intestine will begin to subside, usually within several weeks.
Complete healing and regrowth of the villi may take several months in younger people and as long as two to three years in older people.