Pica (parorexia) is a persistent craving to eat non-food substances: ice, clay, soil, chalk, starch, paper. To speak of pica, this behavior must persist for at least a month and be inappropriate for the person's age and cultural norms.
For adults, pica is an important signal: it is often linked to iron deficiency and can be the first sign of iron-deficiency anemia.
What pica is
Pica occurs in young children (often resolving on its own), in pregnant women and in people with micronutrient deficiencies. A distinct, well-studied variant is pagophagia, an obsessive craving to chew and crunch ice. Pagophagia is considered fairly specific for iron deficiency and often disappears quickly once iron is replenished.
Link to iron and zinc deficiency
The mechanism of pica is not fully understood, but it is consistently linked to a lack of iron, and also zinc — especially during pregnancy. In many people the unusual craving passes after ferritin normalizes and anemia is treated. So pica is not a 'strange habit' but a reason to check iron metabolism.
When to get tested
If the craving for non-food items persists, it is worth taking a complete blood count and ferritin. It is also important to remember the flip side: eating soil, old paint or plaster carries a risk of lead poisoning and intestinal infections. Treatment aims to correct the deficiency and, if needed, address the behavior.
Calculate using this marker
Calculators where Pica is used directly:
Frequently asked questions
Is a craving to chew ice a disease?
A constant craving to chew ice (pagophagia) is a form of pica that often points to iron deficiency. It is worth checking ferritin and a complete blood count; the craving often disappears after iron treatment.
Is pica during pregnancy normal?
A craving for non-food items during pregnancy does occur, but it should not be ignored: it may indicate iron or zinc deficiency. Be sure to tell your doctor and check your blood counts.