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Phytate

Plant phosphate storage compound (inositol hexaphosphate) abundant in whole grains, legumes, nuts, and seeds that binds divalent cations (Fe2+, Zn2+, Ca2+, Mg2+) and reduces their bioavailability.

Also: IP6, Inositol hexaphosphate, Phytic acid

Phytate is the principal dietary inhibitor of nonheme iron and zinc absorption. The phytate:zinc molar ratio is used to grade dietary zinc bioavailability (>15 indicates low absorption). Soaking, fermentation, germination, and addition of phytase reduce phytate. Phytate also has antioxidant and possibly anticancer activity, illustrating MNHD's repeated point that anti-nutrients and nutrients are not cleanly separable.

How one textbook covers it

  • Modern Nutrition in Health and Disease, 12th ed. — Ch 11: Zinc

    Phytate is the principal dietary inhibitor of nonheme iron and zinc absorption. The phytate:zinc molar ratio is used to grade dietary zinc bioavailability (>15 indicates low absorption). Soaking, fermentation, germination, and addition of phytase reduce phytate. Phytate also has antioxidant and possibly anticancer activity, illustrating MNHD's repeated point that anti-nutrients and nutrients are not cleanly separable.

Related terms

Bioavailability, Nonheme iron, Zinc