Phytic acid is an organic acid found in many foods that come from plants, including corn, wheat, rice, and soybeans, and in large amounts in cereals and legumes. It is a mixture of calcium-magnesium salts of inositehexaphosphoric acid, also found in the bran or outer hulls of nuts, seeds, and grains.

Soaking seeds and nuts in water for several hours prior to consumption, and sprouting grains, is advocated in order to reduce the phytic acid content in these foods. Phytic acid may be considered a phytonutrient, providing an antioxidant effect. It may have more therapeutic value when added to water rather than when naturally absorbed in foods, as it is difficult to free from fiber.