NCT04013776

The Impact of a Low or High Phosphate Diet on Phosphate and Calcium Excretion in Healthy People

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 20 (estimated)
• Sponsor: Clinical Evaluation Research Unit at Kingston General Hospital · Academic / Other
• Sex: All
• Age: 20 Years – 40 Years
• Healthy volunteers: Accepted

Summary

Phosphate is present in many of the foods that the investigators eat and is required by many cellular processes. The kidneys are the only organ that excrete the extra phosphate from the diet that the body does not require. Phosphate is linked to vascular calcification and cardiovascular disease. Measures of serum phosphate do not reflect the burden of phosphate and are not sensitive to early changes in the way the kidneys eliminate phosphate. This study will determine whether the kidneys handle an oral phosphate load differently after 5 days of a low phosphate diet compared to 5 days of a high phosphate diet.

Detailed description

In this study, participants will follow a low-phosphorus diet (750 mg) with a 500 mg calcium supplement for 5 days keeping a detailed diary of the foods eaten during this period. On the 5th day, the participant will undergo a 24 hour urine collection. Participants will present after an overnight fast for baseline blood and urine measurements. Then they will consume water containing 500 mg of phosphorus. Urine and blood will be collected every hour for 3 hours for measurement of phosphate and calcium and for measurement of hormones known to regulate phosphate and calcium including fibroblast growth factor-23, parathyroid hormone and vitamin D. One week later, participants will follow the same diet but will also receive a 1250 mg phosphorus supplement for 5 days. On the 5th day, urine will be collected for 24 hours. Participants will present again after an overnight fast and undergo the identical testing.

Conditions

• Cardiovascular Diseases
• Aging
• Nutrient; Excess

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Phosphate supplemented diet	Participants will be asked to follow a 5 day menu of 750 mg of phosphorus daily along with a daily sodium phosphorus supplement of 500 mg

Timeline

• Start date: 2017-05-01
• Primary completion: 2019-09-30
• Completion: 2019-09-30
• First posted: 2019-07-10
• Last updated: 2019-07-12

Locations

1 site across 1 country: Canada