Kidney responses to exercise in heat and whether vitamin B3 changes them.

Development of a Clinical Experimental Heat Stress Protocol and Exploration of the Effect of Niacinamide on Physiologic, Metabolic, and Biochemical Responses to Heat Stress

Early Phase 1 Interventional Beth Israel Deaconess Medical Center · NCT06983730

This project will test whether taking vitamin B3 changes how the kidneys respond when healthy, physically fit adults exercise in hot, humid conditions.

Quick facts

PhaseEarly Phase 1
Study typeInterventional
Enrollment28 (estimated)
Ages18 Years to 45 Years
SexAll
SponsorBeth Israel Deaconess Medical Center Academic / other
Locations2 sites (Boston, Massachusetts and 1 other locations)
Trial IDNCT06983730 on ClinicalTrials.gov

What this trial studies

Healthy adult volunteers will perform supervised exercise on a rowing ergometer inside a controlled hot, humid environmental chamber while researchers collect blood, urine, heart rate, and body temperature measurements. The trial has two optional stages: stage 1 compares chemical and physiologic changes across three exercise sessions of progressively higher intensity, and stage 2 compares two matched exercise sessions in which participants take vitamin B3 on one visit and a placebo on the other. Participants must meet fitness and kidney function criteria (eGFR >90 mL/min/1.73 m2, urine albumin/creatinine <30 mg/g, VO2max 35–60 mL/kg/min) and be nonsmokers without regular vitamin B3 supplementation. The within-person design focuses on NAD+–related metabolic markers and other biomarkers to see how they change with heat stress and with vitamin B3 administration.

Who should consider this trial

Good fit: Ideal participants are healthy, nonsmoking adults who are physically fit (VO2max 35–60 mL/kg/min), have normal kidney function (eGFR >90 mL/min/1.73 m2, urine albumin/creatinine <30 mg/g), and can safely exercise in a hot, humid environment.

Not a fit: People with existing kidney disease, reduced kidney function, inability to exercise safely in heat, active smokers, or those already taking or allergic to vitamin B3 are unlikely to receive benefit from participating.

Why it matters

Potential benefit: If successful, the findings could point to simple ways—like vitamin B3—to modify kidney responses to heat and reduce the risk of heat-related kidney injury.

How similar studies have performed: Human data on using vitamin B3 to alter kidney responses to heat are limited; NAD+–targeted supplements have been studied in other settings, but this application is largely novel and experimental.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Where this trial is running

Boston, Massachusetts and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Heat StrainHealthy Volunteer StudyKidney DysfunctionNAD+NiacinamideVitamin B3Experimental heat strain
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.