An observational study in Vitamin A, Vitamin A Deficiency and Leukoplakia, sponsored by University of Wisconsin, Madison. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-17.
Sponsored by University of Wisconsin, Madison · Observational
This study will determine systemic vitamin A status and lesion histopathology of participants with vocal fold hyperkeratosis resulting in clinical leukoplakia.
The investigator's overarching goal is to determine if there is a pathophysiologic rationale for vitamin A supplementation in the treatment of vocal fold hyperkeratosis. Vocal fold hyperkeratosis is an accumulation of epithelial surface keratin resulting in clinical leukoplakia. It is primarily managed using destructive techniques that risk iatrogenic injury, fibrosis, and voice impairment. Given the potential morbidity of biopsy and lesion removal, there is a need for new approaches to the prevention and treatment of vocal fold leukoplakic disorders that are non-destructive. Vitamin A is a key regulator of epithelial health and systemic vitamin A deficiency could directly contribute to hyperkeratosis. Based on vitamin A's importance to vocal fold stellate and epithelial cell biology and its direct relevance to vocal fold hyperkeratosis, this study will assess vitamin A status in participants with vocal fold hyperkeratosis. An association would suggest further study on the effects of vitamin A optimization and/or supplementation in patients with leukoplakia, as well as an adjuvant therapy in participants for whom surgical treatment is indicated.
67 studies on the registry are indexed under Vitamin A Deficiency; 7 are open to participants now.
This study's enrollment of 50 is below the median of 258 across 17 observational studies indexed under Vitamin A Deficiency.
Browse Vitamin A Deficiency studies →University of Wisconsin, Madison is the lead sponsor of 1,188 studies on the registry; 181 are open to participants now.
Of its 157 completed or terminated interventional studies of FDA-regulated products, 118 (75%) have results posted.
Counted across the registry records on this site, refreshed daily.
Potential participants will be identified from the active caseloads of speech-language pathologists or otolaryngologists. During a routine clinical encounter, a member of the clinical team will inform potential participants of the research opportunity.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Leukoplakia study groups:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy-confirmed diagnosis of hyperkeratosis with dysplasia
Biopsy-confirmed diagnosis of hyperkeratosis with no dysplasia
Laryngoscopy showing no evidence of vocal fold epithelial disease
Vitamin A liver reserves
Total vitamin A liver concentration determined using retinol stable isotope dilution (μmol/g)
Time frame: 14 days
Serum retinol
Serum retinol concentration (μmol/L)
Time frame: Baseline
Serum retinyl esters
Serum retinyl esters concentration (μmol/L)
Time frame: Baseline
Serum carotenoids
Serum carotenoid concentrations (μmol/L)
Time frame: Baseline
Plan to share: No
No publications or documents are linked to this record.
Ran from Jun 2022 to primary completion in Jun 2026, 48 months.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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University of Wisconsin, Madison →