Heat StrainEarly Phase 1NCT06983730
The Kidney's Response to Exercise in Heat, and the Impact of Vitamin B3 on This Response
A Early Phase 1 study testing Vitamin B3 in people with Heat Strain and Healthy Volunteer Study, run by Beth Israel Deaconess Medical Center at 2 sites in United States.
Trial summary
The goal of this clinical trial is to learn about the processes occurring in the kidneys while under heat stress in healthy volunteers. The main questions it aims to answer are: How do the chemicals produced by the body change under conditions of higher versus lower heat stress? What role does a specific area of the… Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Heat Strain, Healthy Volunteer Study, Kidney Dysfunction
- What is being tested?
- Vitamin B3
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 2 sitesUnited States
- Study dates
- 26 Jan 2026to Jun 2028
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy volunteer
- Any race
- Estimated glomerular filtration rate greater than 90 ml/min/1.73m2
- Urine albumin/creatinine ratio less than 30mg/g
- Nonsmoker
- No regular dietary supplements, particularly vitamin B3
- Physically fit, defined as having a VO2 max of between 35 and 60mL/kg/min
Who cannot join
- Medical condition preventing safe participation in exercise during heat
- Allergy to Vitamin B3
- Severe food allergies or dietary restrictions that would preclude eating the planned study diet without major modifications
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites, 2 recruiting
- Recruiting
Beth Israel Deaconess Medical Center
Boston, Massachusetts, 02215
Nathan H Raines, MD MPH, 703-927-0992, nraines@bidmc.harvard.edu
Nathan H Raines, MD MPH
- Recruiting
Boston University
Boston, Massachusetts, 02215
Dustin Allen, PhD, 417-693-2182, drallen@bu.edu
Dustin Allen, PhD
About this study
Official title: Development of a Clinical Experimental Heat Stress Protocol and Exploration of the Effect of Niacinamide on Physiologic, Metabolic, and Biochemical Responses to Heat Stress
The goal of this clinical trial is to learn about the processes occurring in the kidneys while under heat stress in healthy volunteers. The main questions it aims to answer are:
- How do the chemicals produced by the body change under conditions of higher versus lower heat stress?
- What role does a specific area of the body's metabolism, known as NAD+ metabolism, play in the body's response to heat stress, and can this response be modified by taking vitamin B3?
Read the detailed description
To answer these questions, researchers will compare the chemical changes in each participant under progressively higher levels of heat stress, and while taking either vitamin B3 or a placebo.
This clinical trial will occur in two stages. Participants may choose participate in stage 1 only, stage 2 only, or both parts of this clinical trial.
During stage 1, participants will exercise using a stationary rowing ergometer in a hot and humid environmental chamber for three sessions, each session separated by about a week.
- Each session, they will be asked to work out at a progressively higher intensity with climate conditions kept the same in the chamber.
- More intense exercise produces greater heat stress, resulting in lower, moderate, and higher levels of heat stress exposure across the three sessions.
- Researchers will see how chemicals in the blood and urine, along with physical measurements like heart rate and body temperature, change across these different levels of heat stress.
During stage 2, participants will exercise using the same rowing ergometer in the same environmental chamber. They will do this for two sessions, each separated by about a week.
- One of the sessions each participant will take vitamin B3, and the other session each participant will take placebo.
- Heat stress exposure will be the same each session.
- Researchers will again see how chemicals in the blood and urine, along with physical measurements like heart rate and body temperature, differ between sessions with vitamin B3 and sessions with placebo
- Conditions
- Heat Strain, Healthy Volunteer Study, Kidney Dysfunction
- Being tested
- Vitamin B3
- Keywords
- NAD+, Niacinamide, Vitamin B3, Experimental heat strain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin B3Dietary supplement
Also called niacinamide
1000mg once a day orally for two days, once the day before the exercise session, and once the day of the exercise session.
| Study group | Role | What they receive |
|---|---|---|
| Vitamin B3, then placebo | Experimental | Individuals will receive 1000mg oral Vitamin B3 daily for two days leading up to their first exercise session, and oral placebo daily for two days leading up to their second exercise session. Receives: Dietary Supplement: Vitamin B3 |
| Placebo, then vitamin B3 | Experimental | Individuals will receive 1000mg oral placebo daily for two days leading up to their first exercise session, and oral vitamin B3 daily for two days leading up to their second exercise session. Receives: Dietary Supplement: Vitamin B3 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Urinary neutrophil gelatinase-associated lipocalin
Marker of stress and injury in the kidney
Measured: Pre- and immediately post- heat stress exposure
Urinary TIMP2 (tissue inhibitor of metalloproteinase-2) and IGFBP7 (insulin-like growth factor-binding protein 7)
Marker of kidney stress and injury
Measured: Pre- and immediately post- heat stress exposure
Secondary outcomes (2)
Urine Quinolinate to Tryptophan Ratio
Ratio of quinolinate to tryptophan in the urine
Measured: Pre- and immediately post- heat stress exposure
Serum creatinine
Marker of kidney function
Measured: Pre- and immediately post- heat stress exposure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 May 2025
- Study start26 Jan 2026
- Primary completionJun 2028 (estimated)
- Study completionJun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Heat StrainStudies of the same condition, open and under way.
- More trials run by Beth Israel Deaconess Medical CenterThe sponsor's other registered studies.
- 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
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- There are two phases to this study. The first phase is a dose-response phase evaluating the effect of experimental heat strain on kidney metabolic and stress response. The second phase uses this experimental heat strain at a dose producing kidney metabolic and stress response to conduct a crossover trial investigating how Vitamin B3 impacts the kidney's metabolic and stress response during heat strain.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 28 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Beth Israel Deaconess Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Boston University Charles River Campus, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Responsible party
- Principal investigator, Nathan Raines, Beth Israel Deaconess Medical Center
- Investigators
- Nathan H Raines, MD MPH, Principal investigator, Beth Israel Deaconess Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06983730
- Sponsor's protocol ID
- 2024P000637
- Other IDs
- K23DK138320
- Status last verified
- Feb 2026
- First submitted
- 14 May 2025
- Last updated
- 5 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data will be stored in the Harvard Dataverse Repository.
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Development of a Clinical Experimental Heat Stress Protocol and Exploration of the Effect of Niacinamide on Physiologic, Metabolic, and Biochemical Responses to Heat Stress
- ClinicalTrials.gov ID
- NCT06983730
- Acronym / sponsor ID
- 2024P000637
- Conditions
- Heat Strain, Healthy Volunteer Study, Kidney Dysfunction
- Keywords
- NAD+, Niacinamide, Vitamin B3, Experimental heat strain
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 28 participants (estimated)
- Lead sponsor
- Beth Israel Deaconess Medical CenterUniversity, hospital or other
- Collaborators
- Boston University Charles River Campus, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 26 Jan 2026 (actual)
- Primary completion
- Jun 2028 (estimated)
- Study completion
- Jun 2028 (estimated)
- First posted
- 21 May 2025 (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.
The goal of this clinical trial is to learn about the processes occurring in the kidneys while under heat stress in healthy volunteers. The main questions it aims to answer are:
- How do the chemicals produced by the body change under conditions of higher versus lower heat stress?
- What role does a specific area of the body's metabolism, known as NAD+ metabolism, play in the body's response to heat stress, and can this response be modified by taking vitamin B3?
Detailed description
To answer these questions, researchers will compare the chemical changes in each participant under progressively higher levels of heat stress, and while taking either vitamin B3 or a placebo.
This clinical trial will occur in two stages. Participants may choose participate in stage 1 only, stage 2 only, or both parts of this clinical trial.
During stage 1, participants will exercise using a stationary rowing ergometer in a hot and humid environmental chamber for three sessions, each session separated by about a week.
- Each session, they will be asked to work out at a progressively higher intensity with climate conditions kept the same in the chamber.
- More intense exercise produces greater heat stress, resulting in lower, moderate, and higher levels of heat stress exposure across the three sessions.
- Researchers will see how chemicals in the blood and urine, along with physical measurements like heart rate and body temperature, change across these different levels of heat stress.
During stage 2, participants will exercise using the same rowing ergometer in the same environmental chamber. They will do this for two sessions, each separated by about a week.
- One of the sessions each participant will take vitamin B3, and the other session each participant will take placebo.
- Heat stress exposure will be the same each session.
- Researchers will again see how chemicals in the blood and urine, along with physical measurements like heart rate and body temperature, differ between sessions with vitamin B3 and sessions with placebo
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- There are two phases to this study. The first phase is a dose-response phase evaluating the effect of experimental heat strain on kidney metabolic and stress response. The second phase uses this experimental heat strain at a dose producing kidney metabolic and stress response to conduct a crossover trial investigating how Vitamin B3 impacts the kidney's metabolic and stress response during heat strain.
| Arm | Type | Receives |
|---|---|---|
| Vitamin B3, then placebo | Experimental | Dietary Supplement: Vitamin B3Individuals will receive 1000mg oral Vitamin B3 daily for two days leading up to their first exercise session, and oral placebo daily for two days leading up to their second exercise session. |
| Placebo, then vitamin B3 | Experimental | Dietary Supplement: Vitamin B3Individuals will receive 1000mg oral placebo daily for two days leading up to their first exercise session, and oral vitamin B3 daily for two days leading up to their second exercise session. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Healthy volunteer
- Any race
- Estimated glomerular filtration rate greater than 90 ml/min/1.73m2
- Urine albumin/creatinine ratio less than 30mg/g
- Nonsmoker
Key exclusion criteria (3 listed)
- Medical condition preventing safe participation in exercise during heat
- Allergy to Vitamin B3
- Severe food allergies or dietary restrictions that would preclude eating the planned study diet without major modifications
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 |
|---|---|---|
| Vitamin B3Also: niacinamide1000mg once a day orally for two days, once the day before the exercise session, and once the day of the exercise session. | Dietary supplement | Placebo, then vitamin B3, Vitamin B3, then placebo |
Primary outcome
Urinary neutrophil gelatinase-associated lipocalin
Time frame: Pre- and immediately post- heat stress exposure
Marker of stress and injury in the kidney
Urinary TIMP2 (tissue inhibitor of metalloproteinase-2) and IGFBP7 (insulin-like growth factor-binding protein 7)
Time frame: Pre- and immediately post- heat stress exposure
Marker of kidney stress and injury
2 secondary outcomes
Urine Quinolinate to Tryptophan Ratio
Time frame: Pre- and immediately post- heat stress exposure
Serum creatinine
Time frame: Pre- and immediately post- heat stress exposure
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Feb 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data will be stored in the Harvard Dataverse Repository.
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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.
Nathan H Raines, MD MPH principal investigator
Beth Israel Deaconess Medical Center
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Vitamin B3 in people with Heat Strain and Healthy Volunteer Study, run by Beth Israel Deaconess Medical Center at 2 sites 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 7 inclusion and 3 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: looking for participants now, as of the sponsor's last update on 5 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Nathan H Raines, MD MPH (703-927-0992, nraines@bidmc.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Urinary neutrophil gelatinase-associated lipocalin (time frame: Pre- and immediately post- heat stress exposure). 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?
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 5 Feb 2026.