Clinical trial NCT00459485: Effects of Initiation and Discontinuation of Short Term Zinc Supplementation on Plasma Zinc Concentration
Official title: Effects of Initiation and Discontinuation of Short Term Zinc Supplementation on the Magnitude and Velocity of Change in Plasma Zinc Concentration
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Zinc Deficiency
Keywords: Plasm zinc concentration
Zinc supplementation
Assessment of zinc status
Plasma zinc concentration
Lead sponsor: University of California, Davis
Sponsor class: OTHER
Collaborators: name: USDA, Western Human Nutrition Research Center
First posted: 2007-04-12
Enrollment: 58
Sex: MALE
Minimum age (years): 19
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: This is a double-blind, randomized controlled trial conducted in men 19-65 years of age who will receive daily zinc supplements (10 or 20 mg zinc/d as zinc sulfate) or placebo for 21 days. Blood samples for plasma zinc and CRP concentrations will be drawn at baseline and days 1, 2, 5, 9, 14, and 21 during supplementation and days 1, 2, 5, 9, and 14 after discontinuation of supplementation.

Detailed description: The study will be a double blind, randomized, placebo controlled trial conducted in men 19-65 years of age. Participants will receive daily zinc or placebo liquid supplements for 21 days. Supplemental zinc will be given as zinc sulfate; the lower dose zinc supplement will contain 10 mg/d elemental zinc, and the higher dose zinc supplement will contain 20 mg/d elemental zinc. The placebo will contain the same excipients expect for zinc sulfate.

Multiple blood draws will be performed throughout the course of the study, to determine the responsiveness of plasma zinc concentrations to zinc supplementation. Two baseline blood draws will occur prior to the start of supplementation (study days -7 and 0). Blood draws will be performed on days 1, 2, 5, 9, 14 and 21 of the 21 day supplementation period. Upon termination of supplementation (day 21), blood draws will be performed on days 1, 2, 5, 9, 14 and 21 post-supplementation (study days 22, 23, 26, 30, 35 and 42).

The major outcomes of interest are the magnitude and velocity of change in plasma zinc concentration. Other outcomes to be assessed are plasma concentrations of the acute phase proteins CRP and AGP, as well as reported morbidity, because of their potential roles as confounding variables. Anthropometric variables will be assessed at baseline.

Eligibility criteria: Inclusion Criteria:

* Generally health men
* 19-65 years
* Non-anemic

Exclusion Criteria:

* Age \<19 or \>65
* Hemoglobin \<120 g/L
* Clinical evidence of illness
* Consumption of mineral supplements
* Recent blood donation (within 8 weeks)

Primary outcomes:
measure: Plasma zinc concentration
timeFrame: 3 weeks
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: University of California, Davis
name: Kenneth H Brown, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Wessells KR, Jorgensen JM, Hess SY, Woodhouse LR, Peerson JM, Brown KH. Plasma zinc concentration responds rapidly to the initiation and discontinuation of short-term zinc supplementation in healthy men. J Nutr. 2010 Dec;140(12):2128-33. doi: 10.3945/jn.110.122812. Epub 2010 Oct 13.