Hyperoxaluria
Conditions
Brief summary
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.
Detailed description
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.
Interventions
DIETARY_SUPPLEMENTAloe vera with cactus
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.
DIETARY_SUPPLEMENTCranberry
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.
DIETARY_SUPPLEMENTGreen tea extract
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.
DIETARY_SUPPLEMENTBilberry
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.
DIETARY_SUPPLEMENTCinnamon
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.
DIETARY_SUPPLEMENTMilk thistle
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.
DIETARY_SUPPLEMENTTurmeric
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.
DIETARY_SUPPLEMENTAloe vera
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.
Sponsors
University of Wisconsin, Madison
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Within-subject change in 24-hour urinary oxalate excretion from before and after supplementation | 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. |
Countries
United States
Outcome results
None listed