Some contemporary forms of pica have been well publicized: clay eating in Turkey, Iran, and the southern United States, starch eating in our northeastern megopolis, and ice eating (pagophagia) on US Air Force bases.1-3 Of especial poignancy are the illness and death of ghetto children who eat peeling, lead-based paint. Matches-pica used to cause phosphorus poisoning in children. Now the dried paint-pica causes lead poisoning.
Pica usually occurs with iron deficiency. Much discussion of this association has been of the chicken-or-the-egg variety, which comes first? Does iron deficiency cause pica or does pica lead to iron deficiency? When a woman eats little besides laundry starch she is certainly in negative iron balance, and clay evidently contains substances which chelate ionized iron, preventing its absorption. But these are not primary reasons for the iron deficiency-pica syndrome. Coltman found in blind experiments that iron-deficient ice eaters lost the appetite for ice within
Crosby WH. Food Pica and Iron Deficiency. Arch Intern Med. 1971;127(5):960-961. doi:10.1001/archinte.1971.00310170168027