GLOSSARY

Iron Absorption Inhibitors Table

Heme and nonheme iron differ in absorption; meal interactions matter most when iron status or intake is vulnerable.

Iron Absorption varies with heme form, meal composition and body regulation, not food iron quantity alone.

Vitamin C can improve meal nonheme iron absorption, while phytate and tea or coffee polyphenols can reduce it. The whole meal and body status influence the effect; a short-term absorption result is not identical to a definite long-term outcome. During deficiency correction, supplement timing and digestive tolerance are coordinated professionally rather than removing nutritious foods indiscriminately from every athlete's diet.

Minerals must become accessible before crossing through regulated or passive routes. Chemical form, dose, meal composition and body status matter; one fixed absorption percentage does not fit every mineral. Entry into an intestinal cell differs from export to blood and later retention. For supplements, actual elemental amount and interactions are more informative than total compound weight or a universal claim of superior uptake.

Bioaccessibility concerns release from the food matrix and accessibility for absorption; bioavailability concerns the absorbed and usable fraction within a stated framework. Laboratory release does not equal human uptake. Cooking, meal composition, chemical form and body status matter. Practical food choices require actual portions and variety rather than accepting a claim of complete absorption without knowing the measurement method or relevant conditions.

A transporter generally has substrate preferences and finite capacity, so fractional uptake may change as dose rises. Competition depends on substance, concentration and conditions; ordinary foods do not all cancel each other out. Gradual fueling practice and tolerance assessment are useful in sport. Findings from a concentrated experimental dose should not be generalized without context to a mixed meal or an athlete's whole daily diet.

For example, record amount, food form and time before training when assessing a meal; neither a label value nor one blood peak alone establishes complete absorption and use.

Fractional absorption relates absorbed amount to a defined intake, whereas absorption rate expresses amount per time. Rates can differ despite similar final fractions, or the reverse. Specify nutrient, dose and interval when reporting percentages. A rising blood concentration also reflects more than entry because tissue removal and metabolism occur simultaneously. Neither one blood peak nor a rapid label claim establishes total absorption.

For sports use, consider meal size and timing together with fluids, intensity and composition. Large, fiber-rich or fatty meals close to exercise trouble some individuals, but tolerance varies. Changing one factor during training and recording responses helps identify patterns. First-time competition products or broad food exclusions without a replacement plan do not substitute for this practical evaluation and can compromise adequate fueling.

Table references: NIH ODS · 1