Fractional Zinc AbsorptionNCT03934346
Determination of Pre-Absorptive Dissociation of Zinc From a Zinc Amino Acid Complex in Healthy Men
A study testing Zinc amino acid complex in people with Fractional Zinc Absorption, run by UCSF Benioff Children's Hospital Oakland at 1 site in United States.
Trial summary
Zinc may be absorbed from diet via zinc transporter mediated pathways, or, when coupled with amino acids, via amino acid transporter pathways. When zinc is coupled with amino acids in diet, it may dissociate from those amino acids in the acidic environment of the stomach prior to entering the small intestine. Read more about this study
- Who is it for?
- Ages 18 to 50 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Fractional Zinc Absorption
- What is being tested?
- Zinc amino acid complex
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 1 siteUnited States
- Study dates
- 10 Jun 2019to 16 Dec 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Apparently healthy men
- Body mass index between 18 and 30 kg/m2
- Willing to eat only the foods provided by the study for a 2 week period
Who cannot join
- Those reporting any chronic or acute diseases, food allergies, smoking or alcohol abuse
- Use of illicit drugs; regular consumption of medications, micronutrient supplements, or both
- Vegetarians, or those unable to eat meat, are also excluded since the foods for the study contain meat
- Unable to refrain from taking medications during the study period
Trial locations and contacts
1 site in 1 country.
United States1 site
Children's Hospital and Research Center Oakland
Oakland, California, 94609
About this study
Zinc may be absorbed from diet via zinc transporter mediated pathways, or, when coupled with amino acids, via amino acid transporter pathways. When zinc is coupled with amino acids in diet, it may dissociate from those amino acids in the acidic environment of the stomach prior to entering the small intestine. An experimentally-determined value for any pre-absorptive dissociation of zinc from a zinc amino acid complex (ZnAA) is necessary for the accurate compartmental modeling of zinc metabolism when provided as ZnAA compared with ionic zinc, which the investigators will perform in a future study. The current study will allow us to determine the dissociation of zinc from ZnAA, while serving as a pilot test of a novel technique to determine for the first time an individual's zinc transport kinetics.
Read the detailed description
An experimentally-determined value for any pre-absorptive dissociation of zinc from ZnAA is necessary for the accurate compartmental modeling of zinc metabolism when provided as ZnAA compared with zinc chloride, which the investigators will perform in a future study.
The current study will allow us to determine the pre-absorptive dissociation of zinc from ZnAA, while serving as a pilot test of a novel technique to determine for the first time an individual's zinc transport kinetics. Since zinc absorption kinetics follow a saturable process, the zinc transport maximum (Tr_max) and transport rate (K_Tr) can be determined by fitting Hill transport equation to measurements of absorbed zinc at 3 or more levels of zinc intake (mg zinc/d):
Total Absorbed Zinc (TAZ) = (Zinc Intake * Tr_max) / (Zinc Intake + K_Tr)
Although population data have been used to estimate zinc transport kinetics (Tran, et al. AJCN 2004), Tr_max and K_tr have never been determined in individual subjects. The investigators plan to determine the fractional zinc absorption (FZA) from multiple levels of dietary zinc in rapid succession (Chung, et al. AJCN 2004) and, therefore, estimate an individual's transport maximum and rate, Tr_max and K_Tr. Once Tr_max and K_Tr are known, the FZA can be used to determine an unknown zinc intake from zinc chloride and any zinc dissociated from the ZnAA complex using the following equation:
Zinc Intake = (Tr_max / FZA) - K_Tr
Since zinc that dissociates from the ZnAA complex will compete for absorption with the inorganic zinc stable isotopic oral tracer (70-zinc chloride), reducing the amount of that tracer absorbed, the investigators can therefore determine the total zinc intake (the sum of the known zinc in the controlled study diet and the unknown quantity of zinc dissociated from ZnAA pre-absorption) based on the transport kinetics (FZA, Tr_max and KTr).
In other words, for the meal with added ZnAA, the zinc intake is the sum of the zinc in the test meal (3.6 mg zinc and 0.4 mg 70-Zn tracer) and the zinc that dissociates from the ZnAA complex pre-absorption. Since the intact ZnAA (i.e. that zinc that does not dissociate pre-absorption from the ZnAA complex) is absorbed by a different transport mechanism (Sauer, et al. Biometals 2017), it does not compete with the stable isotope tracer for absorption via zinc cation transporters and is, therefore, not part of the "zinc intake" for the purpose of these calculations.
If the hypothesized 20% dissociation is correct (i.e. 3 mg zinc dissociated from an initial 15 mg ZnAA), the total amount of ionic zinc will be 7 mg (the 3.6 mg base diet, 0.4 mg zinc stable isotope tracer, and 3 mg dissociated zinc), and the FZA will therefore be the same as that from a 7 mg test diet (the 3.6 mg base diet, 0.4 mg zinc tracer, and 3 mg zinc as zinc chloride).
- Conditions
- Fractional Zinc Absorption
- Being tested
- Zinc amino acid complex
- Keywords
- zinc, absorption, kinetics, amino acid chelate
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Zinc amino acid complexOther
Zinc in the form of a Zinc Amino Acid Complex (ZnAA) is provided with a test diet, and the amount of zinc that dissociates from the ZnAA and is thus absorbed via an ionic zinc transport pathway is determined based on the Hill transport kinetics for the respective subject.
| Study group | Role | What they receive |
|---|---|---|
| Zinc transport kinetics | Other | Three different amounts of dietary zinc are used in the creation of a standard curve for determining zinc absorption kinetics: 4 mg, 7 mg, and 15 mg of zinc. Receives: Other: Zinc amino acid complex |
What is being measured
The primary outcome is the main question the study is designed to answer.
Zinc Transport Curve
The saturable zinc transport curve determined by fitting the zinc absorption data to the Hill transport equation
Measured: 2 weeks
Dissociated Amino Acid Zinc
Amount of zinc dissociated from the ZnAA prior to absorption
Measured: 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 May 2019
- Study start10 Jun 2019
- Primary completion16 Dec 2019
- Study completion16 Dec 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Fractional Zinc AbsorptionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Nonlinear regression of fractional zinc absorption from 3 test diets using the Hill transport equation, and determination of an unknown amount of zinc based on fractional absorption from a single test diet. Order of the four test diets is randomized, with the constraint that the same oral zinc stable isotope tracer is not given on consecutive days.
- Masking
- None (open label)
- Enrolment
- 13 participants (actual)
Sponsor and investigators
- Lead sponsor
- UCSF Benioff Children's Hospital Oakland
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Andrew G Hall, Ph.D., Principal investigator, UCSF Benioff Children's Hospital Oakland
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03934346
- Sponsor's protocol ID
- 2019-001
- Status last verified
- Jan 2020
- First submitted
- 29 Apr 2019
- Last updated
- 22 Jan 2020
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Chung CS, Stookey J, Dare D, Welch R, Nguyen TQ, Roehl R, Peerson JM, King JC, Brown KH. Current dietary zinc intake has a greater effect on fractional zinc absorption than does longer term zinc consumption in healthy adult men. Am J Clin Nutr. 2008 May;87(5):1224-9. doi: 10.1093/ajcn/87.5.1224.
PubMed 18469243Tran CD, Miller LV, Krebs NF, Lei S, Hambidge KM. Zinc absorption as a function of the dose of zinc sulfate in aqueous solution. Am J Clin Nutr. 2004 Dec;80(6):1570-3. doi: 10.1093/ajcn/80.6.1570.
PubMed 15585770Sauer AK, Pfaender S, Hagmeyer S, Tarana L, Mattes AK, Briel F, Kury S, Boeckers TM, Grabrucker AM. Characterization of zinc amino acid complexes for zinc delivery in vitro using Caco-2 cells and enterocytes from hiPSC. Biometals. 2017 Oct;30(5):643-661. doi: 10.1007/s10534-017-0033-y. Epub 2017 Jul 17.
PubMed 28717982
Study at a glance
From the registry record, last updated by the sponsor on 22 Jan 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Determination of Pre-Absorptive Dissociation of Zinc From a Zinc Amino Acid Complex in Healthy Men
- ClinicalTrials.gov ID
- NCT03934346
- Acronym / sponsor ID
- 2019-001
- Conditions
- Fractional Zinc Absorption
- Keywords
- zinc, absorption, kinetics, amino acid chelate
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 13 participants (actual)
- Lead sponsor
- UCSF Benioff Children's Hospital OaklandUniversity, hospital or other
- Study start
- 10 Jun 2019 (actual)
- Primary completion
- 16 Dec 2019 (actual)
- Study completion
- 16 Dec 2019 (actual)
- First posted
- 1 May 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Zinc may be absorbed from diet via zinc transporter mediated pathways, or, when coupled with amino acids, via amino acid transporter pathways. When zinc is coupled with amino acids in diet, it may dissociate from those amino acids in the acidic environment of the stomach prior to entering the small intestine. An experimentally-determined value for any pre-absorptive dissociation of zinc from a zinc amino acid complex (ZnAA) is necessary for the accurate compartmental modeling of zinc metabolism when provided as ZnAA compared with ionic zinc, which the investigators will perform in a future study. The current study will allow us to determine the dissociation of zinc from ZnAA, while serving as a pilot test of a novel technique to determine for the first time an individual's zinc transport kinetics.
Detailed description
An experimentally-determined value for any pre-absorptive dissociation of zinc from ZnAA is necessary for the accurate compartmental modeling of zinc metabolism when provided as ZnAA compared with zinc chloride, which the investigators will perform in a future study.
The current study will allow us to determine the pre-absorptive dissociation of zinc from ZnAA, while serving as a pilot test of a novel technique to determine for the first time an individual's zinc transport kinetics. Since zinc absorption kinetics follow a saturable process, the zinc transport maximum (Tr_max) and transport rate (K_Tr) can be determined by fitting Hill transport equation to measurements of absorbed zinc at 3 or more levels of zinc intake (mg zinc/d):
Total Absorbed Zinc (TAZ) = (Zinc Intake * Tr_max) / (Zinc Intake + K_Tr)
Although population data have been used to estimate zinc transport kinetics (Tran, et al. AJCN 2004), Tr_max and K_tr have never been determined in individual subjects. The investigators plan to determine the fractional zinc absorption (FZA) from multiple levels of dietary zinc in rapid succession (Chung, et al. AJCN 2004) and, therefore, estimate an individual's transport maximum and rate, Tr_max and K_Tr. Once Tr_max and K_Tr are known, the FZA can be used to determine an unknown zinc intake from zinc chloride and any zinc dissociated from the ZnAA complex using the following equation:
Zinc Intake = (Tr_max / FZA) - K_Tr
Since zinc that dissociates from the ZnAA complex will compete for absorption with the inorganic zinc stable isotopic oral tracer (70-zinc chloride), reducing the amount of that tracer absorbed, the investigators can therefore determine the total zinc intake (the sum of the known zinc in the controlled study diet and the unknown quantity of zinc dissociated from ZnAA pre-absorption) based on the transport kinetics (FZA, Tr_max and KTr).
In other words, for the meal with added ZnAA, the zinc intake is the sum of the zinc in the test meal (3.6 mg zinc and 0.4 mg 70-Zn tracer) and the zinc that dissociates from the ZnAA complex pre-absorption. Since the intact ZnAA (i.e. that zinc that does not dissociate pre-absorption from the ZnAA complex) is absorbed by a different transport mechanism (Sauer, et al. Biometals 2017), it does not compete with the stable isotope tracer for absorption via zinc cation transporters and is, therefore, not part of the "zinc intake" for the purpose of these calculations.
If the hypothesized 20% dissociation is correct (i.e. 3 mg zinc dissociated from an initial 15 mg ZnAA), the total amount of ionic zinc will be 7 mg (the 3.6 mg base diet, 0.4 mg zinc stable isotope tracer, and 3 mg dissociated zinc), and the FZA will therefore be the same as that from a 7 mg test diet (the 3.6 mg base diet, 0.4 mg zinc tracer, and 3 mg zinc as zinc chloride).
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Nonlinear regression of fractional zinc absorption from 3 test diets using the Hill transport equation, and determination of an unknown amount of zinc based on fractional absorption from a single test diet. Order of the four test diets is randomized, with the constraint that the same oral zinc stable isotope tracer is not given on consecutive days.
| Arm | Type | Receives |
|---|---|---|
| Zinc transport kinetics | Other | Other: Zinc amino acid complexThree different amounts of dietary zinc are used in the creation of a standard curve for determining zinc absorption kinetics: 4 mg, 7 mg, and 15 mg of zinc. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Apparently healthy men
- Body mass index between 18 and 30 kg/m2
- Willing to eat only the foods provided by the study for a 2 week period
Key exclusion criteria (4 listed)
- Those reporting any chronic or acute diseases, food allergies, smoking or alcohol abuse
- Use of illicit drugs; regular consumption of medications, micronutrient supplements, or both
- Vegetarians, or those unable to eat meat, are also excluded since the foods for the study contain meat
- Unable to refrain from taking medications during the study period
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Zinc amino acid complexZinc in the form of a Zinc Amino Acid Complex (ZnAA) is provided with a test diet, and the amount of zinc that dissociates from the ZnAA and is thus absorbed via an ionic zinc transport pathway is determined based on the Hill transport kinetics for the respective subject. | Other | Zinc transport kinetics |
Primary outcome
Zinc Transport Curve
Time frame: 2 weeks
The saturable zinc transport curve determined by fitting the zinc absorption data to the Hill transport equation
Dissociated Amino Acid Zinc
Time frame: 2 weeks
Amount of zinc dissociated from the ZnAA prior to absorption
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Jan 2020.
- Background: PubMed 18469243Chung CS, Stookey J, Dare D, Welch R, Nguyen TQ, Roehl R, Peerson JM, King JC, Brown KH. Current dietary zinc intake has a greater effect on fractional zinc absorption than does longer term zinc consumption in healthy adult men. Am J Clin Nutr. 2008 May;87(5):1224-9. doi: 10.1093/ajcn/87.5.1224.
- Background: PubMed 15585770Tran CD, Miller LV, Krebs NF, Lei S, Hambidge KM. Zinc absorption as a function of the dose of zinc sulfate in aqueous solution. Am J Clin Nutr. 2004 Dec;80(6):1570-3. doi: 10.1093/ajcn/80.6.1570.
- Background: PubMed 28717982Sauer AK, Pfaender S, Hagmeyer S, Tarana L, Mattes AK, Briel F, Kury S, Boeckers TM, Grabrucker AM. Characterization of zinc amino acid complexes for zinc delivery in vitro using Caco-2 cells and enterocytes from hiPSC. Biometals. 2017 Oct;30(5):643-661. doi: 10.1007/s10534-017-0033-y. Epub 2017 Jul 17.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Andrew G Hall, Ph.D. principal investigator
UCSF Benioff Children's Hospital Oakland
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Zinc amino acid complex in people with Fractional Zinc Absorption, run by UCSF Benioff Children's Hospital Oakland at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Jan 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Zinc Transport Curve (time frame: 2 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03934346, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Jan 2020.