Actively Recruiting

Phase Not Applicable
Age: 19Years +
All Genders
Healthy Volunteers
NCT04603898

Oxalate Formation From Ascorbic Acid

Led by University of Alabama at Birmingham · Updated on 2026-03-09

136

Participants Needed

1

Research Sites

263 weeks

Total Duration

On this page

Sponsors

U

University of Alabama at Birmingham

Lead Sponsor

N

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborating Sponsor

AI-Summary

What this Trial Is About

The purpose of this basic research study is to determine the contribution of endogenous ascorbic acid (AA) turnover to urinary oxalate excretion in both normal BMI and obese adult non-stone formers and calcium oxalate stone formers. The studies proposed will use diets of known nutrient composition, a stable isotope of ascorbic acid (13C6-AA) and mass spectrometric techniques to quantify ascorbic acid turnover to oxalate.

CONDITIONS

Official Title

Oxalate Formation From Ascorbic Acid

Who Can Participate

Age: 19Years +
All Genders
Healthy Volunteers

Eligibility Criteria

Eligible

You may qualify if you...

  • Able to provide informed consent
  • For stone formers: most recent stone is over 50% calcium oxalate with no uric acid
  • For stone formers: first or recurrent calcium oxalate stone with event in prior 3 years
  • Two 24-hour urine collections with creatinine excretion within 20% of expected for gender and weight
  • Willing to stop supplements (vitamins, calcium, minerals, herbal, probiotics) for 2 weeks before and during study
  • Willing to avoid vigorous exercise during study
  • Normal fasting Comprehensive Metabolic Panel (CMP)
  • Willing to eat menus prepared at Clinical Research Unit
  • No allergies or intolerances to study foods
  • Stable dose of stone prevention medications for at least 8 weeks prior and during screening if applicable; stop allopurinol 2 weeks before screening and during study
Not Eligible

You will not qualify if you...

  • Diabetes
  • Gout
  • Hypertension
  • Estimated glomerular filtration rate (eGFR) below 60 ml/min/1.73m2
  • Primary hyperoxaluria
  • Nephrotic syndrome
  • Enteric hyperoxaluria
  • Renal tubular acidosis
  • Primary hyperparathyroidism
  • Liver disease
  • Autoimmune disorders
  • Neurogenic bladder
  • Urinary diversion
  • Bariatric surgery
  • Active cancer or cancer treatment within 12 months
  • Pregnancy
  • Breastfeeding or nursing
  • Females of childbearing age unable to use effective birth control
  • Mental or medical conditions that may prevent study completion
  • Illness such as flu, cold, or fever within 14 days before or during study
  • Diarrhea or abnormal bowel events within 14 days before or during study
  • Abnormal fasting Comprehensive Metabolic Panel (CMP)

AI-Screening

AI-Powered Screening

Complete this quick 3-step screening to check your eligibility

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Trial Site Locations

Total: 1 location

1

University of Alabama at Birmingham

Birmingham, Alabama, United States, 35243-3353

Actively Recruiting

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Research Team

D

Demond Wiley

CONTACT

How is the study designed?

Study Type

INTERVENTIONAL

Masking

NONE

Allocation

NA

Model

SINGLE_GROUP

Primary Purpose

BASIC_SCIENCE

Number of Arms

1

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