Vitamin D Supplementation for Hormonal Imbalance

Overseen By Giuliet L Kibler

Age: 18 - 65

Sex: Female

Trial Phase: Academic

Sponsor: University of Southern California

Must not be taking: Exogenous hormones, Vitamin D

Disqualifiers: Pregnancy, Gynecological disease, Chronic diseases, others

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 2

Duration: 3 weeks

20 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines how a daily Vitamin D supplement might assist with hormonal imbalances. Participants will receive either a Vitamin D capsule or a placebo (a pill resembling the supplement but without active ingredients) for three weeks. It is ideal for individuals assigned female at birth, aged 18 to 35, without chronic diseases such as tuberculosis or inflammatory bowel disease, and who have not taken Vitamin D supplements in the past three months. The trial aims to determine if Vitamin D can impact hormonal balance management. Researchers will check participants' blood samples before and after the trial to measure any changes. As an unphased study, this trial provides a unique opportunity to advance scientific understanding of Vitamin D's role in hormonal health.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot be taking Vitamin D supplements or exogenous hormones (hormones from outside the body) to participate.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that vitamin D is usually safe when taken in the right amounts. However, excessive intake, such as over 4000 IU daily for an extended period, can raise calcium levels in the blood, potentially causing bone pain or kidney issues. In this study, participants will take 5000 IU of vitamin D each day for just three weeks, a duration much shorter than the long-term use associated with these problems. Although this dose slightly exceeds the usual safe limit, the short duration reduces the risk of serious side effects. Participants should monitor how they feel and report any unusual symptoms to the researchers. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about using Vitamin D for hormonal imbalance because it offers a natural approach that may complement or even enhance existing treatments like hormone therapy. Unlike traditional hormonal treatments, which often involve synthetic hormones, Vitamin D works by potentially regulating hormone levels through its role in calcium and bone metabolism, as well as immune function. This approach might provide a safer alternative with fewer side effects, and there’s growing interest in understanding how Vitamin D's broader health benefits could contribute to balancing hormones in the body.

What evidence suggests that Vitamin D might be an effective treatment for hormonal imbalance?

Research has shown that vitamin D helps maintain hormonal balance. Animal studies have found that a deficiency in vitamin D can reduce fertility and cause growth problems in newborns. Many people take vitamin D supplements to address these issues. Studies have discovered that vitamin D3 raises vitamin D levels in the body more effectively than D2. This trial will test a vitamin D3 supplement, which might improve hormonal balance. ^{6 7 8 9 10}

Who Is on the Research Team?

Giuliet L Kibler

Principal Investigator

University of Southern California - Division of Biokinesiology and Physical Therapy

Are You a Good Fit for This Trial?

This trial is for females experiencing hormonal imbalance. Participants will need to visit the research center twice, complete questionnaires, and allow a small amount of blood to be drawn. They must take a daily capsule for three weeks and keep a survey diary.

Inclusion Criteria

I weigh at least 110 lbs.

I was assigned female at birth.

Completion and signature of the informed consent document

Exclusion Criteria

Pregnant

I have taken Vitamin D supplements in the last 3 months.

I weigh less than 110 lbs.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Baseline Assessment

Initial visit to record height, weight, body composition, complete questionnaires, and withdraw a blood sample

1 day

1 visit (in-person)

Treatment

Participants consume either a placebo capsule or a 5000 IU Vitamin D capsule daily for three weeks and complete a daily survey

3 weeks

Daily self-administration

Post-Treatment Assessment

Second visit to complete the same blood sampling protocol as the baseline assessment

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

2-4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Vitamin D

Trial Overview The study tests if taking high-dose Vitamin D (5000 IU) affects testosterone levels compared to a placebo. It's randomized, meaning participants are put into the Vitamin D or placebo group by chance, and neither the researchers nor participants know who gets what until after the study.

How Is the Trial Designed?

Group I: Vitamin D Group Experimental Treatment 1 Intervention

The treatment intervention will consist of three weeks of one 5000 IU cholecalciferol capsule (Pure Encapsulations, LLC) daily, with breakfast.

Group II: Placebo Group Placebo Group 1 Intervention

The control group will also take a daily, with breakfast, placebo capsule (Zeebo) for the three-week intervention.

Vitamin D is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Vitamin D for:

• Rickets
• Osteomalacia
• Osteoporosis
• Hypocalcemia
• Hyperparathyroidism
• Malabsorption states
• Cirrhosis
• Obesity

Approved in European Union as Vitamin D for:

• Rickets
• Osteomalacia
• Osteoporosis
• Hypocalcemia
• Hyperparathyroidism
• Malabsorption states
• Cirrhosis
• Obesity

Approved in Canada as Vitamin D for:

• Rickets
• Osteomalacia
• Osteoporosis
• Hypocalcemia
• Hyperparathyroidism
• Malabsorption states
• Cirrhosis
• Obesity

Who Is Running the Clinical Trial?

University of Southern California

Lead Sponsor

Trials

956

Recruited

1,609,000+

Published Research Related to This Trial

Vitamin D3 (cholecalciferol) is more effective than Vitamin D2 (ergocalciferol) in raising serum levels of 25-hydroxyvitamin D, which is a key measure of vitamin D status in the body.

Due to its superior bioefficacy, Vitamin D2 should not be considered a suitable option for supplementation or fortification, as it has a shorter shelf life and less effective binding to vitamin D binding protein in plasma.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The case against ergocalciferol (vitamin D2) as a vitamin supplement. Houghton, LA., Vieth, R.[2023]

In a study involving 40 healthy participants, both vitamin D2 and D3, when consumed at low doses (5 or 10 μg/d), significantly increased serum levels of their respective metabolites (25-OH-D2 and 25-OH-D3) over a 4-week period with minimal UV-B exposure.

The results indicated that vitamin D2 and D3 are equally effective in raising serum 25-hydroxy-vitamin D levels, suggesting that either form can be used to improve vitamin D status in individuals with low UV-B exposure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fortified malted milk drinks containing low-dose ergocalciferol and cholecalciferol do not differ in their capacity to raise serum 25-hydroxyvitamin D concentrations in healthy men and women not exposed to UV-B. Fisk, CM., Theobald, HE., Sanders, TA.[2018]

Vitamin D, including both D2 and D3, is crucial for regulating calcium and phosphate metabolism, which are essential for bone health and overall bodily functions.

The body produces vitamin D3 in the skin through sunlight exposure, and it is then converted into its active form, calcitriol, in the liver and kidneys, highlighting the importance of both sunlight and organ function in maintaining vitamin D levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Vitamin D metabolism]. Kulda, V.[2013]

In a study of 64 adults aged 65 and older, vitamin D3 (cholecalciferol) was found to be slightly more effective than vitamin D2 (ergocalciferol) in increasing serum 25-hydroxyvitamin D levels over one year, with 19% of participants still having low levels despite high compliance.

Neither vitamin D2 nor D3 caused toxicity or significant changes in serum calcium or other bone markers, but about 20% of individuals still had insufficient vitamin D levels after treatment, indicating variability in individual responses to supplementation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluation of ergocalciferol or cholecalciferol dosing, 1,600 IU daily or 50,000 IU monthly in older adults. Binkley, N., Gemar, D., Engelke, J., et al.[2022]

Cholecalciferol (vitamin D3) is the most effective and stable form of vitamin D for supplementation, while ergocalciferol (vitamin D2) is less potent and more prone to degradation during storage and cooking.

Current nutrition guidelines often overlook that calcidiol and calcitriol are not nutrients suitable for food fortification or dietary supplementation, emphasizing the need to focus on cholecalciferol for effective vitamin D intake.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Vitamin D supplementation: cholecalciferol, calcifediol, and calcitriol. Vieth, R.[2021]

In a study of 279 adults, both vitamin D2 and D3 supplements significantly increased 25-hydroxy D levels compared to placebo, with the highest increases observed in those taking D3 on a 2-weekly schedule.

The effectiveness of vitamin D2 and D3 in raising 25-hydroxy D levels was found to be influenced by dosing schedule and sex, with females showing a greater response to both forms of vitamin D.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Differential effects of vitamin D2 and D3 supplements on 25-hydroxyvitamin D level are dose, sex, and time dependent: a randomized controlled trial. Hammami, MM., Yusuf, A.[2018]

Calcifediol (25-OH-vitamin D3) is more effective than cholecalciferol (vitamin D3) in preventing and treating vitamin D deficiency, with a rapid onset of action and greater potency, as shown in studies lasting over 6 months.

Both calcifediol and cholecalciferol are safe for the general population, but calcifediol does not increase toxicity levels, making it a preferable option for vitamin D supplementation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Treatment of Vitamin D Deficiency with Calcifediol: Efficacy and Safety Profile and Predictability of Efficacy. Pérez-Castrillon, JL., Usategui-Martín, R., Pludowski, P.[2023]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9372493/

Effectiveness of vitamin D2 compared with vitamin D3 ... The vitamin D3 injection alone or with a D2 tablet was associated with the highest treatment response compared to a vitamin D2 injection alone after adjusting ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S2161831323013947

Comparison of the Effect of Daily Vitamin D2 and ... The results based on 20 comparative studies showed vitamin D3 to be superior to vitamin D2 in raising total 25(OH)D concentrations.

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Consensus Statement on Vitamin D Status Assessment and ... There are many preclinical data on the extraskeletal effects of the vitamin D endocrine system, including gene regulation, cellular function, ...

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The health effects of vitamin D supplementation: evidence ... Vitamin D supplementation can prevent and cure nutritional rickets in infants and children. Preclinical and observational data suggest that ...

5. news-medical.net news-medical.net/health/The-Role-of-Vitamin-D-in-Hormonal-Balance.aspx

The Role of Vitamin D in Hormonal Balance Animal-based experiments revealed that 25(OH)D deficiency reduced fertility rates, compromised mating behavior, and impaired neonatal growth. Decreased maternal ...

6. ods.od.nih.gov ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

Vitamin D - Health Professional Fact Sheet Vitamin D overview for health professionals. Research health effects, dosing, sources, deficiency symptoms, side effects, and interactions ...

7. webmd.com webmd.com/vitamins/ai/ingredientmono-929/vitamin-d

Vitamin D - Uses, Side Effects, and More Taking vitamin D for long periods of time in doses higher than 4000 IU (100 mcg) daily is possibly unsafe and may cause very high levels of calcium in the blood ...

8. ncbi.nlm.nih.gov ncbi.nlm.nih.gov/books/NBK557876/

Vitamin D Toxicity - StatPearls - NCBI Bookshelf Toxicity of vitamin D leads to hypercalcemia and an imbalance in the regulation of bone metabolism; the resultant hypercalcemia leads to clinical ...

9. academic.oup.com academic.oup.com/jcem/article/99/4/1132/2537181

Vitamin D Supplementation and Risk of Toxicity in Pediatrics Safety data were collected and reviewed. Evidence Synthesis: A small number of pediatric studies tested vitamin D doses at or above the currently recommended ...

10. frontiersin.org frontiersin.org/journals/nutrition/articles/10.3389/fnut.2025.1579957/full

Cholecalciferol (vitamin D3): efficacy, safety, and ... While vitamin D supplementation is generally safe within recommended limits, excessive intake may cause hypercalcemia or nephrolithiasis, emphasizing the need ...