Which form of iron is the most bioavailable?

• A. Heme iron.
• B. Elemental iron.
• C. Reduced iron.
• D. Non-heme iron.

Answer: (A)

Verified step by step guidance

1. Understand the concept of bioavailability: Bioavailability refers to the proportion of a nutrient that is absorbed and utilized by the body. In the case of iron, different forms have varying levels of bioavailability.
2. Identify the two main forms of dietary iron: Heme iron and non-heme iron. Heme iron is found in animal-based foods (e.g., meat, poultry, fish), while non-heme iron is found in plant-based foods (e.g., beans, lentils, spinach).
3. Recognize the bioavailability of heme iron: Heme iron is more bioavailable because it is absorbed directly into the intestinal cells without requiring conversion. This makes it easier for the body to utilize.
4. Compare non-heme iron: Non-heme iron has lower bioavailability because its absorption is influenced by dietary factors, such as the presence of vitamin C (which enhances absorption) or phytates (which inhibit absorption).
5. Conclude that heme iron is the most bioavailable form of iron, as it is absorbed more efficiently compared to elemental iron, reduced iron, or non-heme iron.