In the people intolerant to gluten, even a small quantity of gluten results in autoimmune activity that harms the finger like structures called villi in the intestine. This results in malabsorption of nutrients, and various problems of the intestine like chronic diarrhea and malabsorption of nutrients. Quite like any other autoimmune disorder, it is not rare for the celiac disease to be present along with other disorders of an autoimmune mechanism like type 1 diabetes(2), thus further complicating the food choice.
If a person remains undiagnosed, celiac disease may lead to weight loss and other health problems as a result of malnutrition. In people suffering from gluten intolerance there often a deficiency of minerals like iron, calcium, magnesium, zinc, and deficit of vitamins like vitamin B12, niacin, folate, vitamin D, and riboflavin (3).
So it is important for people suffering from celiac to have a completely gluten free diet.