Iron deficiency with or without anemia is considered the most widespread nutritional deficiency in the world. To diagnose iron deficiency anemia (hemoglobin and ferritin measurement), a venous blood sample is necessary. Whole saliva is a potentially attractive fluid for disease biomarker discovery and diagnostic efforts, because it is readily available from most individuals, can be easily collected and the collection procedure is non-invasive. The iron storage protein ferritin is too big, to be secreted into saliva. However, the main iron regulatory protein hepcidin is a very small protein and there is some evidence for hepcidin detection in saliva. The production of serum hepcidin positively correlates with serum ferritin, thereby reflecting patient's iron status. Whether hepcidin is detectable in saliva and whether saliva hepcidin correlates with serum hepcidin with current assays, needs to be tested.

Inclusion Criteria:

• Normal-weight (BMI 18-24.9kg/m2)
• fasting
• Participants Need to have brushed their teeth at least 1 hour before the visit

Exclusion Criteria:

• acute, chronic illness
• use of long-term medication other than contraception
• medical Problems known to affect Fe homeostasis
• smoking

healthy volunteers, male and female