This is a condition characterized by a deficiency of an enzyme called lactase, which is necessary for the digestion of sugars found in milk or other dairy products. Untreated celiac disease often leads to the destruction of villi in the small intestine and thus, a decrease in production of lactase, leading to secondary lactose intolerance. It is estimated that lactose intolerance is present in about one-fourth of the cases of celiac disease. However, there is also a direct relationship between celiac disease and lactose intolerance. So, someone suffering from lactose intolerance is also at a much higher risk of developing celiac disease. Following a gluten-free diet has shown excellent results, as it results in healing the villous atrophy and a renewed production of lactase.