Clinical trial NCT06610968: Acute Vitamin D Supplementation on Testosterone in Females
Official title: Effects of Acute Vitamin D Supplementation on Testosterone in Young, Healthy Females: a Pilot Study
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Female Hormone Profile
Lead sponsor: University of Southern California
Sponsor class: OTHER
First posted: 2024-09-24
Enrollment: 20
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention 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.
Primary purpose: HEALTH_SERVICES_RESEARCH

Brief 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. 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.

Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Hormonal Effects of Vitamin D in Young, Healthy Women
timeFrame: 3 weeks
measure: Hormonal Effects of Vitamin D in Young, Healthy Women
timeFrame: 3 weeks
measure: Hormonal Effects of Vitamin D in Young, Healthy Women
timeFrame: 3 weeks
measure: Hormonal Effects of Vitamin D in Young, Healthy Women
timeFrame: 3 weeks
Secondary outcomes:
measure: Effects of Body Composition on Hormonal Changes Due to Vitamin D Supplementation in Young, Healthy Women
timeFrame: 3 weeks
measure: Effects of Body Composition on Hormonal Changes Due to Vitamin D Supplementation in Young, Healthy Women
timeFrame: 3 weeks
Other outcomes:
Locations:
city: Los Angeles
country: United States
facility: University of Southern California Health Sciences Campus Center for Health Professions
state: California
Study officials:
affiliation: University of Southern California - Division of Biokinesiology and Physical Therapy
name: Giuliet L Kibler
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.