Zinc Supplements in Lowering Cadmium Levels in Smokers
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT00376987 |
Recruitment Status :
Completed
First Posted : September 15, 2006
Last Update Posted : May 30, 2017
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
RATIONALE: Zinc supplements may lower cadmium levels in smokers and may help prevent DNA damage.
PURPOSE: This clinical trial is studying how well zinc supplements work in lowering cadmium levels in smokers.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Bladder Cancer Cervical Cancer Esophageal Cancer Gastric Cancer Head and Neck Cancer Kidney Cancer Leukemia Liver Cancer Lung Cancer Pancreatic Cancer Tobacco Use Disorder | Dietary Supplement: zinc oxide | Phase 2 |
OBJECTIVES:
- Determine whether zinc supplements reduce cadmium levels in smokers.
- Measure serum levels of cotinine (a biomarker of smoking), zinc (a marker of compliance), and cadmium (the dependent variable) at 3 pre-supplementation visits and at 6 supplementation visits.
- Determine whether serum cadmium levels (adjusted for serum levels of cotinine) decrease during supplementation with VisiVite Smoker's Formula.
- Determine if increased cadmium levels in the blood of cigarette smokers can be correlated with decreased mismatch repair.
- Determine if administration of zinc-containing supplements reverses cadmium-induced inhibition of mismatch repair.
OUTLINE: This is an open-label, nonrandomized study.
Patients receive oral zinc supplements once daily for 12 weeks in the absence of unacceptable toxicity.
Blood, serum, and urine are collected once weekly for 3 weeks before beginning treatment and in weeks 5, 6, 9, 12, 15, and 17 for biomarker/laboratory analysis. Samples are examined for cadmium, zinc, and cotinine levels by atomic absorption spectrophotometry, expression of mismatch repair proteins (MSH2, MSH6, MSH3, MLH1, and PMS2), levels of messenger RNA by reverse transcriptase-polymerase chain reaction, and microsatellite instability by gel electrophoresis.
After completion of study therapy, patients are followed for 5 weeks.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 61 participants |
Allocation: | Non-Randomized |
Intervention Model: | Single Group Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Prevention |
Official Title: | Do Dietary Supplements of Zinc Reduce Serum Cadmium Levels in Smokers? |
Study Start Date : | December 2003 |
Actual Primary Completion Date : | October 2006 |
Actual Study Completion Date : | June 2015 |

- Dietary Supplement: zinc oxide
Oral daily dietary supplement containing 80 mg Zinc oxide
- Reduction of cadmium levels [ Time Frame: 17 weeks ]
- Serum levels of cotinine, zinc, and cadmium at 3 pre-supplementation visits and at 6 supplementation visits [ Time Frame: 17 weeks ]
- Correlation of increased cadmium levels with decreased mismatch repair [ Time Frame: 17 weeks ]
- Reversal of cadmium-induced inhibition of mismatch repair [ Time Frame: 17 weeks ]

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 21 Years to 120 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
DISEASE CHARACTERISTICS:
- Currently smoking ≥ 1 pack (20 cigarettes) per day
- Baseline cadmium level ≥ 0.5 μg/L
PATIENT CHARACTERISTICS:
- Negative pregnancy test
- Fertile patients must use effective contraception
- No known gastrointestinal upset due to zinc vitamins or lozenges
PRIOR CONCURRENT THERAPY:
- At least 2 weeks since prior and no other concurrent vitamins and zinc supplements

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00376987
United States, North Carolina | |
Wake Forest University Comprehensive Cancer Center | |
Winston-Salem, North Carolina, United States, 27157-1096 |
Principal Investigator: | Gary G. Schwartz, MD, PhD, MPH | Wake Forest University Health Sciences |
Responsible Party: | Wake Forest University Health Sciences |
ClinicalTrials.gov Identifier: | NCT00376987 |
Other Study ID Numbers: |
CDR0000495325 CCCWFU-98903 CCCWFU-BG03-538 |
First Posted: | September 15, 2006 Key Record Dates |
Last Update Posted: | May 30, 2017 |
Last Verified: | September 2015 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
renal cell carcinoma bladder cancer cervical cancer esophageal cancer gastric cancer adult acute myeloid leukemia pancreatic cancer hypopharyngeal cancer lip and oral cavity cancer |
laryngeal cancer nasopharyngeal cancer oropharyngeal cancer paranasal sinus and nasal cavity cancer non-small cell lung cancer small cell lung cancer adult primary liver cancer tongue cancer tobacco use disorder |
Lung Neoplasms Pancreatic Neoplasms Stomach Neoplasms Uterine Cervical Neoplasms Urinary Bladder Neoplasms Esophageal Neoplasms Liver Neoplasms Tobacco Use Disorder Neoplasms Respiratory Tract Neoplasms Thoracic Neoplasms Neoplasms by Site Lung Diseases Respiratory Tract Diseases Digestive System Neoplasms |
Endocrine Gland Neoplasms Digestive System Diseases Pancreatic Diseases Endocrine System Diseases Gastrointestinal Neoplasms Gastrointestinal Diseases Stomach Diseases Head and Neck Neoplasms Uterine Neoplasms Genital Neoplasms, Female Urogenital Neoplasms Uterine Cervical Diseases Uterine Diseases Urologic Neoplasms Urinary Bladder Diseases |