Why does the FDA use 18 mg as the reference?

18 mg reflects the RDA for adult women, who generally need more iron than men due to menstrual blood loss; it's used as a single label reference value for all adults.

Does this account for iron absorption differences?

No, %DV reflects the amount of iron present, not how well your body absorbs it — plant-based (non-heme) iron is generally absorbed less efficiently than animal-based (heme) iron.

Iron Daily Value (%DV) Calculator

Calculate the Percent Daily Value (%DV) of iron in a food or supplement based on the current FDA reference daily intake of 18 mg, useful for tracking iron intake for anemia prevention or dietary planning.

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% Daily Value: 19.4%

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Formula

%DV = (Iron mg / 18 mg) × 100

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