Effect of the Consumption of Ferric Hydroxide Adipate on Urinary Phosphorus Excretion.
Status:
Completed
Trial end date:
2009-10-01
Target enrollment:
Participant gender:
Summary
Ferric hydroxide adipate is a ferric iron supplement containing iron hydroxide and a dietary
organic acid that was developed at MRC Human Nutrition Research. We aim to determine if the
ingestion of ferric hydroxide adipate with food induces a reduction in urinary phosphate
concentration, compared with the administration of placebo plus the same food on a different
occasion. We hypothesise that ferric hydroxide adipate binds some phosphate ions in the
gastrointestinal tract, which prevents part of the phosphate load in a meal from being
absorbed. On another visit, calcium will be given with the same food, as a positive control,
since this element is well known to restrict dietary phosphate absorption through the
formation of insoluble calcium phosphates in the gut lumen. We will compare urinary phosphate
concentrations after co-ingestion of the calcium salt and food versus urinary phosphate
following ferric hydroxide adipate and the same food. Additionally, the calcium data will be
compared with placebo data, since a significant reduction in urinary phosphate concentrations
after calcium treatment will confirm the suitability of the study design.
Finally, iron absorption from the ferric hydroxide adipate treatment will be determined by
labelling this preparation with 58Fe and measuring day 14 erythrocyte 57Fe:58Fe.
The study design is: Three-way cross-over volunteer absorption study. Volunteers will not be
told which treatment they receive (placebo, ferric hydroxide adipate, or supplemental
calcium). Researchers co-ordinating the study on a day to day basis will be aware of
treatment allocation, but analysts will not be told which samples correspond to which
treatments.