One of the classical examples of a direct interaction between a vitamin and a mineral is the enhancing effect of ascorbic in non-heme iron absorption.
Ascorbic acid has an important role for iron nutrition in humans, and a deficiency interferes with iron metabolism.
For the absorption of dietary non-heme iron, ascorbic acid prevents the formation of insoluble and unabsorbed iron compounds or complexes and reduces the ferric ion to the ferrous ion, which seems to be requirements for the uptake of iron into mucosal cells.
The amount of ascorbic acid needed to inhibit phytate binding to iron depends on the amount of phytate present in the gastrointestinal tract.
The greater the amount of phytate that is present, the more ascorbic acid is required to reverse the inhibition.
The intestinal absorption of iron also is inhibited in the presence of the essential trace elements copper and zinc.
A four to fivefold increase in iron absorption is observed when ascorbic acids is added to the simultaneous application of iron and copper or iron and zinc when compared to application without ascorbic acid.
Ascorbic acid affects the mobilization and distribution of minerals ions throughout the body. For example, ascorbic acid stimulates iron incorporation into ferritin from the iron bound transferrin, stabilizes ferritin and enhances iron-induced ferritin translation in human cells. All these activities are able to increase iron bioavailability.
Ascorbic acid supplements can cause a change in the distribution of iron in a patient suffering from iron overload, but not necessarily in other individuals.
Ascorbic acid-iron interaction
