Bioavailability Definition

Bioavailability refers to a degree and rate at which a nutrient is absorbable or made available at the site of physiological activity.

For example, calcium is present in high amounts in spinach, but oxalic acid in spinach inhibits calcium absorption in the small intestine, so calcium from spinach is less bioavailable than, for example, calcium from sardines.

Another example is erythritol, a sugar polyol, which is readily absorbed but not used by the body, which means it is not bioavailable.

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