Iron is involved in many vital metabolic processes such as oxygen transport, electron transport in cells, DNA synthesis and repair, and muscle metabolism. However, iron deficiency and iron deficiency anemia continue to affect many people, particularly preschool children (<5 years), adolescents, and pregnant and non-pregnant women of childbearing age. Iron deficiency is characterized by a lack of total iron stores in the body, which is mainly caused by insufficient dietary iron intake, physiologically increased iron requirements, poor intestinal iron absorption, or chronic blood loss. Animal foods are important sources of highly bioavailable iron in the human diet. Meeting human nutritional needs for the rapidly increasing world population while targeting food production within the planetary boundaries will require the identification of sustainable iron sources, such as edible insects. A previous iron absorption study showed that insect iron is absorbed moderately well. The present study will examine if and to which extent chitin, a polysaccharide within the insect biomass, inhibits iron absorption. In addition, the enhancing iron absorption of ascorbic acid on iron absorption from Tenebrio molitor larvae will be studied. This knowledge can support to optimize the composition of an insect-based meal to increase its iron absorption.

To distinguish iron absorption from insect biomass from other sources, insects are labeled with stable iron isotopes (Fe-57, Fe-58, Fe-54) and iron absorption in the blood is measured.

Inclusion Criteria:

• Female aged between 18-45 years
• Normal BMI (18.5 - 24.9 kg/m2)
• Body weight < 70 kg
• Low iron status (being in the lower half of the serum ferritin distribution at screening)

Exclusion Criteria:

• Anaemia (Hb < 12 g/dL)
• Inflammation (CRP > 5.0 mg/L)
• Pregnancy or intention to become pregnant during the study or within 30 days after the discontinuation of the study intervention
• Lactating up to 6 weeks before the study initiation
• Chronic digestive, renal and/or metabolic diseases
• Antibiotics in the last 4 weeks prior to the study and during the study
• Mineral and vitamin supplementation in the last 2 weeks prior to the study and during the course of the study
• Chronic medication intake (except for oral contraceptives)
• Blood transfusion, blood donation or significant blood loss (accident, surgery) over the past 4 months
• Earlier participation in a study using stable isotopes or in any clinical study within the last 30 days
• Food allergies, especially known hypersensitivity to crustacea, dust mites, sea food, gluten, milk, or eggs
• Cigarette smoking (> 1 cigarette per day)

The randomization will be single-blinded, i.e., the participants will not know which type of test meal they will be given on which study visit.