Iron Absorption: Factors, Limitations, and Improvement Methods

Abstract

Iron is an essential element for human life since it participates in many functions in the human body, including oxygen transport, immunity, cell division and differentiation, and energy metabolism. Iron homeostasis is mainly controlled by intestinal absorption because iron does not have active excretory mechanisms for humans. Thus, efficient intestinal iron bioavailability is essential to reduce the risk of iron deficiency anemia. There are two forms of iron, heme and nonheme, found in foods. The average daily dietary iron intake is 10 to 15 mg in humans since only 1 to 2 mg is absorbed through the intestinal system. Nutrient–nutrient interactions may play a role in dietary intestinal iron absorption. Dietary inhibitors such as calcium, phytates, polyphenols and enhancers such as ascorbic acid and proteins mainly influence iron bioavailability. Numerous studies have been carried out for years to enhance iron bioavailability and combat iron deficiency. In addition to traditional methods, innovative techniques are being developed day by day to enhance iron bioavailability. This review will provide information about iron bioavailability, factors affecting absorption, iron deficiency, and recent studies on improving iron bioavailability.

Microencapsulation of Erythrocytes Extracted from Cavia porcellus Blood in Matrices of Tara Gum and Native Potato Starch

“…Iron absorption occurs mainly in the duodenum, and it is known that heme iron enhances the absorption of non-heme iron, the latter being much less consumed in developing countries [ 39 ]. A daily intake of 10 to 15 mg of iron in the human diet is recommended, so the erythrocytes obtained in the present research could be used in fortified foods with prior food safety studies [ 15 , 40 , 41 ]. Microencapsulation is one of the most recommended techniques to achieve a controlled release of iron [ 42 , 43 , 44 , 45 ].…”

“…At 120 min, the T4C treatment presented the highest result of 94.71%, followed by the T1C treatment, whose value was 91.71%. Likewise, high values of iron release could also be appreciated in the other treatments (T2C, T3C, T5C, and T6C), whose bioavailability in the small intestine is essential to reduce the risk of suffering from anemia since only 1 to 2 mg of iron is absorbed in this part of the human body [ 15 ].…”

“…Food fortification and oral iron supplementation are the most used mechanisms for the prevention and treatment of anemia, and they are performed to protect and release the mineral at the right time and place [ 15 ], with encapsulation being the most used method, which allows inhibiting the different mechanisms of reaction and degradation of bioactive compounds, during the incorporation of ingredients to food systems, this process allows protecting the nucleus with various matrices such as starches, maltodextrins, gums, lipids, carbohydrates, proteins and antioxidants [ 16 ]. The most commonly applied encapsulation methods in the food industry are emulsification [ 17 ], gelation [ 18 ], extrusion [ 19 ], spray drying [ 20 ] and lyophilization [ 21 ], and there are also chemical encapsulation techniques such as coacervation, co-crystallization, interfacial polymerization, ionic gelation, polymeric incompatibility, liposome entrapment and molecular inclusion [ 22 ].…”

Food fortification strategies to deliver nutrients for the management of iron deficiency anaemia

“…These include germination, soaking, fermentation, and thermal or mechanical processing ( Suma and Urooj, 2014 ; Gupta et al, 2015 ; Samtiya et al, 2021 ). Furthermore, the consumption of “iron inhibitors” like foods rich in polyphenols (red wine, tea, cocoa or coffee) along with meals, may also reduce iron absorption in the body ( Piskin et al, 2022 ).…”

Regulation of iron transport is required for terminal erythroid differentiation even under iron-replete conditions that are sufficient for hemoglobinization

“…Addressing this hypothesis, and determining how iron facilitates erythroid development, is critical for optimizing therapeutics for iron deficiency anemia. Conceptually, this is an important question as little is understood mechanistically as to how transition metals are handled in different cellular contexts and employed as effectors of developmental signaling, despite the well-established role of transition metals in cellular differentiation (11)(12)(13)(14)(15)(16).…”