Vasfelszívódás

Vasfelszívódás refers to the process by which the human body absorbs iron from the digestive tract, primarily in the small intestine. This process is crucial for maintaining adequate iron levels, which are essential for oxygen transport, energy production, and various enzymatic functions.

There are two main forms of dietary iron: heme iron and non-heme iron. Heme iron is found in animal products like red meat, poultry, and fish. It is absorbed more efficiently and directly through specific transporters in the intestinal cells. Non-heme iron, found in plant-based foods such as legumes, leafy greens, and fortified cereals, as well as in inorganic iron supplements, is absorbed less efficiently.

The absorption of non-heme iron is significantly influenced by other dietary components. Vitamin C (ascorbic acid) is a well-known enhancer of non-heme iron absorption, as it reduces ferric iron (Fe3+) to ferrous iron (Fe2+), which is more readily absorbed. Conversely, certain substances can inhibit absorption. Phytates, found in whole grains and legumes, and polyphenols, present in tea, coffee, and red wine, can bind to non-heme iron and reduce its bioavailability. Calcium can also interfere with iron absorption.

Iron absorption is tightly regulated by the body's iron status. When iron stores are low, the body increases absorption efficiency. Conversely, when iron stores are high, absorption is reduced to prevent iron overload. This regulation is largely mediated by hepcidin, a hormone produced by the liver. Hepcidin controls the amount of iron released from intestinal cells into the bloodstream.