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Completed

NCT Number: NCT02404701

Effect of Over-the-counter Dietary Supplements on Kidney Stone Risk

The purpose of this study is to ascertain whether certain supplements promote excessive urinary oxalate excretion and increase the risk for calcium oxalate kidney stones. Supplements that enhance urinary oxalate excretion, as a result of their oxalate concentration or from some other mechanism (e.g., providing substrate for oxalate biosynthesis) will be identified by the investigators.

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Key information

Conditions

Hyperoxaluria Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Kidney Diseases Male Urogenital Diseases Urogenital Diseases Urologic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Urology, School of Medicine & Public Health, University of Wisconsin

Madison, Wisconsin, 53705-2281, United States

About this study

The investigators hypothesize that certain over-the-counter dietary supplements will increase urinary excretion of oxalate as measured in 24-h urine collections. The investigators further hypothesize that the concentration of oxalate in dietary supplements may not be associated with urinary oxalate excretion, suggesting that other nutritional components of the supplements may be exerting an influence over oxalate biosynthesis, oxalate absorption in the gastrointestinal tract, and/or renal oxalate handling. These other factors include the form of oxalate in the supplement (water- vs. non water-soluble) and the supplement's concentration of ascorbic acid.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • At least 18 years of age, no prior personal history of kidney stones

Exclusion criteria

  • Personal history of kidney stones (by subjects' report); known allergy to any of the dietary supplements to be used in the study (by subjects' report); short bowel; active ulcerative colitis or irritable bowel disease; Crohns or Celiac disease; renal tubular acidosis; current use of topiramate or other carbonic anhydrase inhibitor, steroids, allopurinol, thiazide diuretics, or supplemental ascorbic acid >250 mg/day.

Treatment and study plan

Aloe vera with cactus

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Walgreens

cranberry

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Puritan's Pride

Green Tea Extract

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Puritan's Pride

Bilberry

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Puritan's Pride

Cinnamon

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Puritan's Pride

Milk thistle

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Puritan's Pride

Turmeric

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Puritan's Pride

Aloe Vera

Dietary Supplement

Eligible participants who provide consent/authorization will report for an orientation visit (1 of 3 visits), during which participants will: provide a medical history and a 24-hour diet recall, have height and weight measured, learn how to collect 24-hour urine, receive instructions on following a standardized diet for 7 days, learn to use a food scale and provide diet records, and receive a 4-day supply of the supplement they were allocated to take along with instructions. After 3 days on the diet (no supplement), participants will return their first (of 2) diet record and 24-hour urine collection. After 4 days on the diet while taking the supplement, participants will return their second (and final) completed diet record and their second (and final) 24-hour urine collection.

Other names: Puritan's Pride

Primary outcomes

  1. Within-subject change in 24-hour urinary oxalate excretion from before and after supplementation

    Time frame: 7 days

    24-hour urine samples will be analyzed for oxalate by ion chromatography. The difference in oxalate between the baseline (non-supplement) and supplement phase will be assessed.

Sponsors and collaborators

Lead sponsor

University of Wisconsin, Madison

Other

Registry information

Important dates

Study start
2015
Primary completion
2016
Study completion
2016
First posted
Mar 31, 2015
Registry last updated
Oct 27, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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