Bioavailability

Heme iron and synthetic iron exhibit differences in how effectively the body absorbs and utilises them. Heme iron, predominantly found in animal-based foods, boasts higher bioavailability compared to synthetic iron. Bioavailability refers to the amount of a nutrient that the body can absorb and use effectively.

The unique structure of heme iron found in hemoglobin and myoglobin in animal tissues allows for efficient absorption in the intestines. This characteristic absorption mechanism enables the body to utilise a more substantial portion of heme iron consumed compared to its synthetic counterpart.

Conversely, synthetic iron, often in the form of supplements or fortified foods, contains non-heme iron. This form of iron doesn't absorb as efficiently as heme iron. Factors such as the presence of inhibitors in certain foods and lower absorption rates contribute to the decreased bioavailability of synthetic iron.

Side Effects

Synthetic iron supplements can cause gastrointestinal discomfort, including nausea, and abdominal pain. One of the most common side effects of synthetic iron is constipation. Iron supplements can slow down bowel movements and cause stools to become hard and difficult to pass.

The form in which synthetic iron is presented in supplements can be harsh on the digestive system. Some forms of iron, such as ferrous sulfate or ferrous fumarate, can irritate the stomach lining, causing discomfort, nausea, or even gastritis.

Heme iron, found in animal-based foods, has fewer side effects due to better absorption and its natural form, minimising gastrointestinal issues.