**6. Ferropenic anaemia and associated CD**

Anaemia without other clinical signs of intestinal malabsorption is one of the most common extra-intestinal manifestations of CD [37]. CD is frequently diagnosed in patients referred for evaluation for iron deficiency anaemia, which is found in 1.8–14.6% of patients [38].

A prospective study conducted in patients with iron deficiency anaemia published in 2005 [39] reported a 5% prevalence of celiac disease. Subsequent studies have confirmed that between 4 and 6% of patients with refractory iron deficiency anaemia of unknown origin have CD. Associated autoimmune gastritis is found in 20–27% of patients, 50% of whom also have an associated active *H. pylori* infection that responds effectively to the eradicating treatment.

The most obvious cause of this anaemia is a decrease in intestinal absorption of iron and other nutrients, including folate and cyanocobalamin. Villous atrophy of the intestinal mucosa is a significant cause of the decrease in iron absorption, as confirmed by the microcytic and hypochromic anaemia revealed in the haemograms of the majority of anaemic patients with CD [40].

The decreased absorption of iron in CD is also revealed by the failure of the serum iron levels to increase following oral administration of iron supplements, whereas the problem is resolved rapidly when iron is administered parenterally.
