Hormonal changes induced by changing amounts of protein and phosphorus in the diet of healthy volunteers

Effects of changes in dietary phosphorus intake on fibroblast growth factor 23 (FGF23) levels in healthy volunteers: a controlled crossover trial

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN10876564

Enrollment

Registered

2010-05-27

Start date

2008-08-01

Completion date

Unknown

Last updated

2015-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Kidney disease Urological and Genital Diseases Chronic nephritic syndrome

Interventions

Subjects are switched from regular diet to phosphate-restricted diet for two days, and the back to regular diet for ten days. After that they are switched from regular diet to phopsphate-enriched diet

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Male or female 2. Non-smoking subjects 3. Normal renal function, as defined by estimated Glomerular Filtration Rate (GFR) above 80 ml/min. 4. Females should have a negative test for pregnancy at baseline

Exclusion criteria

Exclusion criteria: 1. Abnormal kidney function 2. Substantial comorbidity

Design outcomes

Primary

Measure	Time frame
Changes in FGF23 levels, determined using sandwich ELISA for both C-terminal FGF23 (provided by Immutopics, San Clemente, USA) and Intact FGF23 (provided by Kainos, Japan).	—

Secondary

Measure	Time frame
1. Changes in phosphaturia 2. Changes in levels of metaboliotes of vitamin D (1,25 dihydroxyvitamin D) Outcomes analysed by standard laboratory techniques and radio-immuno assay (IDS, Tyne and Wear, UK) respectively	—

Countries

Netherlands

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026