I heard this question the other day and thought it odd anyone would suggest consuming the placenta is pica, but I wanted to address it just the same.
Pica is a disorder characterized by cravings for non-nutrient substances such as clay, chalk, paint, etc. It can occur during pregnancy. It is sometimes linked to an iron or zinc deficiency.
Implying that placenta consumption is pica signifies a misunderstanding of the placenta and why consuming it would be beneficial.
The placenta is not a non-nutritive substance. It contains lots of nutrition. Interestingly enough, if a woman recently having given birth was experiencing pica due to iron deficiency, the placenta would be a great resource for helping to correct the underlying deficiency causing the pica as the placenta is full of iron.
The placenta may not be the most common thing to eat, but it is certainly not pica. It contains nutrition. It has multiple benefits for a woman recently having given birth and therefore has a purpose to consuming it. We can safely put this rumor to rest.