Let's see what types exist depending on the rate of absorption: - Heme iron: It is found in foods of animal origin, such as red meat, poultry (turkey, chicken) and fish (salmon, sardines).

While Rh and ABO are the most common blood groups, MAL is different from them, due to an absence of an antigen called AnWj.

People who consume high amounts of red meat and other animal products may be at a risk of type 2 diabetes, mainly because of the content of heme iron in the food items, say Harvard researchers.