Geophagy

Geophagy, literally “earth eating,” also known as pica (technically the consumption of all inappropriate materials), is the practice of consuming dirt, typically clays. Geophagy may be practiced for either health or religious reasons. Devout Christians and Muslims have engaged in ritualized forms of geophagy for centuries, typically in the form of wafers ostensibly derived from holy sites.

Geophagy was widely practiced in many preindustrial societies, particularly in tropical environments and most commonly by pregnant women to relieve the nausea of pregnancy. Through trial-and-error experimentation, many cultures learned to compensate for nutritional deficiencies of trace minerals or vitamins, particularly sulfur, zinc, calcium, phosphorus, potassium, magnesium, and manganese, by consuming certain forms of clay. Consumption of dirt rich in iron is helpful in regions where people suffer from ...