๐Ÿ›๏ธ Verified NIH Record โ€ข Updated 2026-08-27

Urinary Vitamin C Loss in Diabetic Subjects (NCT00071526)

Urinary Vitamin C Loss in Subjects With and Without Diabetes

๐ŸŸข Recruiting Interventional Protocol ๐Ÿ“Š Observational Clinical Research Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

๐Ÿฉบ Plain-English Summary (8th-Grade Level)

Several studies have reported that diabetic subjects have lower plasma vitamin C concentrations than non-diabetic subjects. Although urinary vitamin C loss in diabetic subjects was reported to be increased in two studies, these are difficult to interpret due to lack of controlled vitamin C intake, inadequate sampling, lack of control subjects, or methodology uncertainties in vitamin C assay and sample processing. Consequently, it is unclear whether diabetic subjects truly have both low plasma and high urine vitamin C concentrations. We propose that low plasma vitamin C concentrations in diabetic subjects are due in part to inappropriate renal loss of vitamin C in these subjects but not in healthy controls. We will study nondiabetic controls and cohorts with diabetes. Vitamin C concentrations in plasma, RBCs, and urine will be measured in outpatients. In those willing to be admitted to the Clinical Center, we will measure vitamin C pharmacokinetics to determine the relative bioavailability for vitamin C in individuals with and without abnormal urinary loss of vitamin C (or renal leak). Single nucleotide polymorphisms (SNPs) will be determined in genomic DNA responsible for the two proteins mediating sodium dependent vitamin C transport, SVCT1 and SVCT2. We will also explore mechanisms underlying abnormal urinary vitamin C loss....

Who can join: Review the eligibility criteria below.

Location: National Institutes of Health Clinical Center โ€” Bethesda, Maryland

Age range: 18 Years to 65 Years

๐Ÿ“‹ "Do I Qualify?" โ€” 1-Minute Self Screener

Instant Checklist

Full eligibility criteria are available on the official NIH protocol. View the criteria โ†—

๐Ÿ“ All Participating Trial Locations (1 Sites)

  • National Institutes of Health Clinical Center โ€” Bethesda, Maryland

๐Ÿ“ž Contact the Study Coordinator

Phone: (301) 827-5757

Email: razi.berman@nih.gov

Coordinator details come directly from the registered NIH protocol. Confirm the study is still recruiting before traveling.

๐Ÿ’ฐ Cost, Insurance & Patient Rights

  • 100% Free Items: The investigational treatment and protocol-required procedures are supplied at zero cost by the sponsor.
  • Routine Patient Care: Under federal law (ACA ยง 2709) and many state statutes, routine care costs are covered during participation.
  • Voluntary Participation: You may withdraw at any time without affecting your standard medical care.

Explore by condition: All Diabetes clinical trials

๐Ÿ’ก How to Participate

  1. Check the checklist above to see if you may qualify.
  2. Contact the study coordinator using the phone/email above.
  3. Ask about the visit schedule, what is covered at no cost, and any travel support.
  4. Confirm with your own doctor before making a decision.
๐Ÿ›๏ธ View Official NIH Record โ†—