Female Hormone ProfileNCT06610968
Acute Vitamin D Supplementation on Testosterone in Females
A study testing Vitamin D (Cholecalciferol ) in people with Female Hormone Profile, run by University of Southern California at 1 site in United States.
Trial summary
Participation will take place over two visits to the Clinical Exercise Research Center (CERC) at the University of Southern California Health Sciences Campus. On the first visit, height, weight, and body composition by bioelectrical impedance are recorded. Read more about this study
- Who is it for?
- Ages 18 to 35 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Female Hormone Profile
- What is being tested?
- Vitamin D (Cholecalciferol )
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jul 2025to 30 Sep 2026
- Phase
- Interventional
- 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 35 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Assigned female at birth
- 18 to 35 years of age
- No chronic diseases affecting the uptake of Vitamin D or causing Vitamin D sensitivity (e.g., sarcoidosis, tuberculosis, Wegener's granulomatosis, other forms of vasculitis, inflammatory bowel diseases, etc.) [21]
- Completion and signature of the informed consent document
- Non-pregnant or trying to become pregnant
- No supplementation with Vitamin D within three months of enrollment
- No documented gynecological disease (e.g., PCOS, endometriosis, etc.)
- Weight greater than or equal to 110 lbs
Who cannot join
- Pregnant
- Supplementation with Vitamin D within three months of enrollment
- Taking exogenous hormones
- Documented gynecological disease (e.g., PCOS, endometriosis, etc.)
- Suffering from chronic diseases affecting the uptake of Vitamin D or causing Vitamin D sensitivity (e.g., sarcoidosis, tuberculosis, Wegener's granulomatosis, other forms of vasculitis, inflammatory bowel diseases, etc.) [21]
- Weight less than 110 lbs
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Southern California Health Sciences Campus Center for Health Professions
Los Angeles, California, 90033
About this study
Official title: Effects of Acute Vitamin D Supplementation on Testosterone in Young, Healthy Females: A Pilot Study
Participation will take place over two visits to the Clinical Exercise Research Center (CERC) at the University of Southern California Health Sciences Campus.
On the first visit, height, weight, and body composition by bioelectrical impedance are recorded. Questionnaires and withdrawal of a sample of blood (1 tablespoon) are also completed. The intervention begins the day following the first visit. The intervention protocol consists of three weeks of consuming either a placebo capsule or a 5000 IU Vitamin D capsule daily and completing a daily survey.
The second visit to CERC immediately follows the 3-weeks intervention. In this visit, the same blood sampling protocol will be completed. The assignment of the intervention will be randomized (i.e., rolling a die), and participants are blinded to group assignment.
Read the detailed description
High-dose Vitamin D supplementation significantly increases testosterone in men, but research about Vitamin D's effect on testosterone in young, healthy females is limited [1]. However, testosterone is a critical hormone for many physiologic functions in females including maintenance of reproductive health, cognitive function, body composition, mental health, bone density, muscle strength, and much more. Thus, this study aims to investigate the effect of Vitamin D supplementation on testosterone and gonadotropin concentrations in premenopausal, healthy females. The study investigators hypothesize that Vitamin D supplementation will result in a significant increase in circulating Vitamin D [25(OH)D], testosterone, and sex hormone modulators (i.e., gonadotropins and SHBG) concentrations in pre-menopausal females and that the magnitude of testosterone increase will be inversely related to fat mass and BMI. 20 young, healthy females will be randomized to either a treatment or placebo group for a three-week intervention, where the control group will take 5000 IU of Vitamin D orally, daily and the placebo group will take a placebo capsule orally, daily. Circulating Vitamin D, testosterone, gonadotropin, and SHBG concentrations will be assessed via serum pre- and post-intervention. Two-tailed unpaired t-test will be conducted to assess the relative change in total testosterone and free testosterone levels between the groups. Additionally, correlation analyses will be performed for correlations between body composition metrics and 25(OH)D, testosterone, and sex hormone modulator concentrations.
- Conditions
- Female Hormone Profile
- Being tested
- Vitamin D (Cholecalciferol ), Placebo Group
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin D (Cholecalciferol )Dietary supplement
Also called 5000 IU Vitamin D daily
5000 IU Vitamin D (as cholecalciferol) capsules (Vitamin D3 125 mcg [5,000 IU], Pure Encapsulation, LLC) daily
Placebo GroupDietary supplement
Also called Placebo (Zeebo) pill daily
One placebo capsule (Zeebo Imagine, Zeebo) daily.
| Study group | Role | What they receive |
|---|---|---|
| Vitamin D Group | Experimental | The treatment intervention will consist of three weeks of one 5000 IU cholecalciferol capsule (Pure Encapsulations, LLC) daily, with breakfast. Receives: Dietary Supplement: Vitamin D (Cholecalciferol ) |
| Placebo Group | Placebo comparator | The control group will also take a daily, with breakfast, placebo capsule (Zeebo) for the three-week intervention. Receives: Dietary Supplement: Placebo Group |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hormonal Effects of Vitamin D in Young, Healthy Women
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating testosterone (total testosterone and free testosterone) concentrations (ng/dL) will be assessed via serum pre- and post-Vitamin D intervention.
Measured: 3 weeks
Hormonal Effects of Vitamin D in Young, Healthy Women
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating Vitamin D [25(OH)D] concentrations (ng/dL) will be assessed via serum pre- and post-Vitamin D intervention.
Measured: 3 weeks
Hormonal Effects of Vitamin D in Young, Healthy Women
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating gonadotropins (LH and FSH) concentrations (IU/L) will be assessed via serum pre- and post-Vitamin D intervention.
Measured: 3 weeks
Hormonal Effects of Vitamin D in Young, Healthy Women
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating SHBG concentrations (nmol/L) will be assessed via serum pre- and post-Vitamin D intervention.
Measured: 3 weeks
Secondary outcomes (2)
Effects of Body Composition on Hormonal Changes Due to Vitamin D Supplementation in Young, Healthy Women
Secondary analyses will evaluate the effect of body composition on change in testosterone concentration due to acute Vitamin D supplementation of pre-menopausal, healthy females. Testosterone (TT and FT) concentrations will be correlated with body composition metrics, i.e. fat and fat-free mass (kg), pre- and post-Vitamin D intervention.
Measured: 3 weeks
Effects of Body Composition on Hormonal Changes Due to Vitamin D Supplementation in Young, Healthy Women
Secondary analyses will evaluate the effect of body composition on change in testosterone concentration due to acute Vitamin D supplementation of pre-menopausal, healthy females. Testosterone (TT and FT) concentrations will be correlated with body composition metrics, i.e. BMI (kg/m^2) as measured from height (m) and weight (kg), pre- and post-Vitamin D intervention.
Measured: 3 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Sep 2024
- Study start1 Jul 2025
- Primary completion5 Mar 2026
- Study completion30 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Female Hormone ProfileStudies of the same condition, open and under way.
- More trials run by University of Southern CaliforniaThe 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
- Phase N/A
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomized to either a treatment or control group upon enrollment and blinded to group assignment. The treatment intervention will consist of three weeks of one 5000 IU cholecalciferol capsule (Pure Encapsulations, LLC) daily, with breakfast. The control group will also take a daily, with breakfast, placebo capsule (Zeebo) for the three-week intervention.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Southern California
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Todd Schroeder, University of Southern California
- Investigators
- Giuliet L Kibler, Principal investigator, University of Southern California - Division of Biokinesiology and Physical Therapy
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06610968
- Sponsor's protocol ID
- HS-24-00403
- Status last verified
- Mar 2026
- First submitted
- 17 Sep 2024
- Last updated
- 25 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Pilz S, Frisch S, Koertke H, Kuhn J, Dreier J, Obermayer-Pietsch B, Wehr E, Zittermann A. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011 Mar;43(3):223-5. doi: 10.1055/s-0030-1269854. Epub 2010 Dec 10.
PubMed 21154195
Study at a glance
From the registry record, last updated by the sponsor on 25 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Acute Vitamin D Supplementation on Testosterone in Young, Healthy Females: A Pilot Study
- ClinicalTrials.gov ID
- NCT06610968
- Acronym / sponsor ID
- HS-24-00403
- Conditions
- Female Hormone Profile
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of Southern CaliforniaUniversity, hospital or other
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- 5 Mar 2026 (actual)
- Study completion
- 30 Sep 2026 (estimated)
- First posted
- 24 Sep 2024 (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.
Participation will take place over two visits to the Clinical Exercise Research Center (CERC) at the University of Southern California Health Sciences Campus.
On the first visit, height, weight, and body composition by bioelectrical impedance are recorded. Questionnaires and withdrawal of a sample of blood (1 tablespoon) are also completed. The intervention begins the day following the first visit. The intervention protocol consists of three weeks of consuming either a placebo capsule or a 5000 IU Vitamin D capsule daily and completing a daily survey.
The second visit to CERC immediately follows the 3-weeks intervention. In this visit, the same blood sampling protocol will be completed. The assignment of the intervention will be randomized (i.e., rolling a die), and participants are blinded to group assignment.
Detailed description
High-dose Vitamin D supplementation significantly increases testosterone in men, but research about Vitamin D's effect on testosterone in young, healthy females is limited [1]. However, testosterone is a critical hormone for many physiologic functions in females including maintenance of reproductive health, cognitive function, body composition, mental health, bone density, muscle strength, and much more. Thus, this study aims to investigate the effect of Vitamin D supplementation on testosterone and gonadotropin concentrations in premenopausal, healthy females. The study investigators hypothesize that Vitamin D supplementation will result in a significant increase in circulating Vitamin D [25(OH)D], testosterone, and sex hormone modulators (i.e., gonadotropins and SHBG) concentrations in pre-menopausal females and that the magnitude of testosterone increase will be inversely related to fat mass and BMI. 20 young, healthy females will be randomized to either a treatment or placebo group for a three-week intervention, where the control group will take 5000 IU of Vitamin D orally, daily and the placebo group will take a placebo capsule orally, daily. Circulating Vitamin D, testosterone, gonadotropin, and SHBG concentrations will be assessed via serum pre- and post-intervention. Two-tailed unpaired t-test will be conducted to assess the relative change in total testosterone and free testosterone levels between the groups. Additionally, correlation analyses will be performed for correlations between body composition metrics and 25(OH)D, testosterone, and sex hormone modulator concentrations.
Study design
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Participants will be randomized to either a treatment or control group upon enrollment and blinded to group assignment. The treatment intervention will consist of three weeks of one 5000 IU cholecalciferol capsule (Pure Encapsulations, LLC) daily, with breakfast. The control group will also take a daily, with breakfast, placebo capsule (Zeebo) for the three-week intervention.
| Arm | Type | Receives |
|---|---|---|
| Vitamin D Group | Experimental | Dietary Supplement: Vitamin D (Cholecalciferol )The treatment intervention will consist of three weeks of one 5000 IU cholecalciferol capsule (Pure Encapsulations, LLC) daily, with breakfast. |
| Placebo Group | Placebo comparator | Dietary Supplement: Placebo GroupThe control group will also take a daily, with breakfast, placebo capsule (Zeebo) for the three-week intervention. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Assigned female at birth
- 18 to 35 years of age
- No chronic diseases affecting the uptake of Vitamin D or causing Vitamin D sensitivity (e.g., sarcoidosis, tuberculosis, Wegener's granulomatosis, other forms of vasculitis, inflammatory bowel diseases, etc.) [21]
- Completion and signature of the informed consent document
- Non-pregnant or trying to become pregnant
Key exclusion criteria (6 listed)
- Pregnant
- Supplementation with Vitamin D within three months of enrollment
- Taking exogenous hormones
- Documented gynecological disease (e.g., PCOS, endometriosis, etc.)
- Suffering from chronic diseases affecting the uptake of Vitamin D or causing Vitamin D sensitivity (e.g., sarcoidosis, tuberculosis, Wegener's granulomatosis, other forms of vasculitis, inflammatory bowel diseases, etc.) [21]
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 D (Cholecalciferol )Also: 5000 IU Vitamin D daily5000 IU Vitamin D (as cholecalciferol) capsules (Vitamin D3 125 mcg [5,000 IU], Pure Encapsulation, LLC) daily | Dietary supplement | Vitamin D Group |
| Placebo GroupAlso: Placebo (Zeebo) pill dailyOne placebo capsule (Zeebo Imagine, Zeebo) daily. | Dietary supplement | Placebo Group |
Primary outcome
Hormonal Effects of Vitamin D in Young, Healthy Women
Time frame: 3 weeks
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating testosterone (total testosterone and free testosterone) concentrations (ng/dL) will be assessed via serum pre- and post-Vitamin D intervention.
Hormonal Effects of Vitamin D in Young, Healthy Women
Time frame: 3 weeks
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating Vitamin D [25(OH)D] concentrations (ng/dL) will be assessed via serum pre- and post-Vitamin D intervention.
Hormonal Effects of Vitamin D in Young, Healthy Women
Time frame: 3 weeks
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating gonadotropins (LH and FSH) concentrations (IU/L) will be assessed via serum pre- and post-Vitamin D intervention.
Hormonal Effects of Vitamin D in Young, Healthy Women
Time frame: 3 weeks
The primary objective is to evaluate the effect of acute Vitamin D supplementation on systemic Vitamin D, testosterone, and sex hormone modulators in pre-menopausal, healthy females. Circulating SHBG concentrations (nmol/L) will be assessed via serum pre- and post-Vitamin D intervention.
2 secondary outcomes
Effects of Body Composition on Hormonal Changes Due to Vitamin D Supplementation in Young, Healthy Women
Time frame: 3 weeks
Effects of Body Composition on Hormonal Changes Due to Vitamin D Supplementation in Young, Healthy Women
Time frame: 3 weeks
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 25 Mar 2026.
- Background: PubMed 21154195Pilz S, Frisch S, Koertke H, Kuhn J, Dreier J, Obermayer-Pietsch B, Wehr E, Zittermann A. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011 Mar;43(3):223-5. doi: 10.1055/s-0030-1269854. Epub 2010 Dec 10.
- Individual participant dataSharing planned: No
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.
Giuliet L Kibler principal investigator
University of Southern California - Division of Biokinesiology and Physical Therapy
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Vitamin D (Cholecalciferol ) in people with Female Hormone Profile, run by University of Southern California 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 8 inclusion and 6 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: under way, not looking for participants, as of the sponsor's last update on 25 Mar 2026. 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. Some participants in this study may receive a placebo. 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?
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?
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?
Hormonal Effects of Vitamin D in Young, Healthy Women (time frame: 3 weeks). The study lists 4 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 NCT06610968, which also lists 1 linked publication.
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 25 Mar 2026; AzTrials last refreshed its copy on 8 Nov 2026.