Iron Balance in Humans Living at High Altitude Using Stable Iron Isotopes to Define Requirements and Biomarker Thresholds

What this Trial Is About

Researchers are investigating how living at different altitudes affects iron absorption and losses in the body. The study focuses on people living below 1000 meters and above 1500 meters in Switzerland to better understand if daily iron intake recommendations and diagnostic thresholds for iron deficiency anemia should be adjusted for high-altitude populations. The study enrolls healthy adults aged 18 to 45 to fill knowledge gaps regarding iron balance influenced by oxygen availability at altitude. Participants will receive a single oral dose of stable iron isotopes (15 mg of ferrous sulphate 57FeSO4) combined with vitamin C and syrup to improve absorption and taste. The two groups differ only by their residence altitude, with no other interventions applied. The study includes a long-term observation period where iron turnover is tracked through isotope measurements in blood samples taken at four visits over the second year following isotope administration. During the four visits at months 12, 16, 20, and 24, blood samples will be collected to measure isotope concentration and several iron-related biomarkers including hemoglobin mass, ferritin, hepcidin, transferrin receptor, CRP, AGP, erythropoietin, and erythroferrone. Hemoglobin mass will be measured twice using a carbon monoxide rebreathing method. Participants will also complete questionnaires on diet and physical activity. This comprehensive monitoring aims to determine iron absorption, losses, and the impact of altitude on iron balance over time.

Determination of Iron Absorption and Losses in People Living at High Altitude to Investigate the Requirements in This Population Group Using a Newly Developed Technique