Funding for this research was provided by:
Phosphoric Acid & Phosphate Producers Associations
Received: 21 August 2017
Accepted: 22 January 2018
First Online: 16 February 2018
Ethics approval and consent to participate
: This study was approved by the Ethical Committee of the Friedrich Schiller University Jena (no.: 3987-01/14). Written informed consent was obtained from all subjects. The trial is registered at ExternalRef removed as NCT02095392.
: Not applicable
: The authors declare that they have no competing interests.
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