Millions of women go through menopause every year. Most will develop genitourinary syndrome of menopause, or GSM. Few will hear their doctor say those words out loud. GSM is common, but doctors rarely treat it. That gap is exactly why nonhormonal options like vitamin D deserve a closer look.
What is genitourinary syndrome of menopause?
GSM is the modern term for what used to be called vaginal atrophy. It describes a group of changes that happen when estrogen drops during menopause. The vaginal lining thins and loses elasticity and moisture. The vaginal pH rises, which can invite irritation and infection.
Symptoms include vaginal dryness, burning, and itching. Many women also experience pain during sex, known as dyspareunia. Urinary symptoms are common too, including urgency, frequent urination, and recurrent urinary tract infections.
Following menopause, most women experience symptoms of GSM. For example, approximately 75% of women experience vaginal dryness, 40% report pain during intercourse, and 30% to 40% experience urinary urgency and frequency. GSM also affects breast cancer survivors due to the anti-estrogen therapies common for breast cancer treatment.
Despite how common GSM is, most women stay quiet about it. Embarrassment, lack of awareness, and the assumption that nothing can help all keep women from bringing it up.
That silence carries a real cost. GSM can strain relationships, fuel anxiety and depression, and even push women out of the workforce. Menopause symptoms cost the U.S. economy an estimated $1.8 billion a year in lost productivity.
Hormone therapy to treat GSM
Vaginal estrogen is the most effective treatment for GSM. It restores collagen, thickens the vaginal lining, and normalizes pH. But some women cannot or choose not to use estrogen therapy. In the past, doctors often told women with a history of hormone-sensitive breast cancer to avoid estrogen therapy. That advice held even at low doses, because of concerns about cancer recurrence.
However, we now know that it is generally safe. Authors of a 2022 review of the use of intravaginal estrogen after menopause reported:
“Licensed doses of intravaginal oestrogen do not elevate systemic estradiol levels above the normal postmenopausal range with long term use and there is no evidence of an increased risk of coronary heart disease, stroke, thromboembolism, colorectal cancer, endometrial cancer, breast cancer or breast cancer recurrence with their use.”
“…there is no evidence of an increased risk of coronary heart disease, stroke, thromboembolism, colorectal cancer, endometrial cancer, breast cancer or breast cancer recurrence with (intravaginal estrogen).”
— Laing, A. J., Newson, L., & Simon, J. A. (2022) The Cancer Journal
Yet vaginal estrogen simply isn’t available in many countries. Egypt, Saudi Arabia, and the United Arab Emirates are three examples where regulators restrict topical estrogen products. In some cases, the products simply aren’t available. For women there, hormonal treatment isn’t a choice to weigh. It’s off the table entirely.
Nonhormonal options and a lesser-known contender
Moisturizers and prescription alternatives
Nonhormonal care for genitourinary syndrome usually starts with vaginal moisturizers and lubricants. Most rely on hyaluronic acid, and they can ease dryness without affecting hormone levels. They don’t rebuild vaginal tissue, though, or improve urinary symptoms of GSM.
Two nonhormonal prescription drugs are also available to treat GSM. Ospemifene is an oral medication that acts on estrogen receptors in vaginal tissue. Prasterone, sold as a vaginal insert, converts into small amounts of estrogen and androgen locally. The FDA approves both, and they’re available in North America, Europe, and a few other countries. That leaves a real gap for women who want more than a moisturizer but can’t access these drugs or hormonal therapy at all.
Vitamin D
This gap has pushed researchers to find alternative treatments for GSM. A number of studies have considered a less familiar candidate: vitamin D. Vitamin D receptors exist throughout the vaginal lining. That finding has led scientists to ask whether vitamin D, taken orally or applied vaginally, might help rebuild vaginal tissue the way estrogen does. The research is thin compared to hormonal therapy, but it has been building quietly for two decades.
What a recent cohort study found
A 2026 study in Future Science OA, led by Christopher Massaad and colleagues at Saint George University of Beirut and the Lebanese University, examined vaginal vitamin D for GSM.
How the study was designed
The researchers included 110 postmenopausal women with GSM symptoms such as dryness, dyspareunia (pain associated with sex), and urinary urgency. Within the main group, the researchers split women across four arms:
- Control group — 35 women who were not treated in the study
- Probiotic group — 38 women received probiotic Lactobacillus
- Vaginal vitamin D group — 30 women used a 10,000 IU vitamin D vaginal suppository three times a week for two months, then twice weekly for maintenance.
- Combination group — 5 women used vitamin D plus probiotics together.
What improved
The results looked strong on the surface. Every woman who received vitamin D in one analysis (10 of 10) was symptom-free at three months, compared to 34% (10 of 29) of women who didn’t receive it, a statistically significant difference. Over the full treatment period, 96.7% of the vitamin D group was in remission at six months, compared with 76.3% of the probiotic-only group and 62.9% of the control group. The small combination group that used vitamin D with probiotics reported 100% remission, though only five women were in that group.
Specific symptoms improved too. Dryness got better in 83.3% of the vitamin D group versus 51.4% of controls. Dyspareunia improved in 70.0% versus 42.9%. Urinary urgency improved in 63.3% versus 40.0%. Sexual function scores, measured with the Female Sexual Function Index, rose from an average of 19.6 to 26.4, moving many women from a range associated with sexual dysfunction into a healthier range.
Study limitations
This was a small cohort study, not a randomized clinical trial. The study followed women who either chose their treatments themselves or received them from clinicians in real clinical practice. Additionally, most participants had already received antibiotics, antifungals, or probiotics for underlying infections before the vitamin D phase even started. This likely led to the relatively high remission rate in the control group. The authors acknowledge this directly, writing that larger randomized trials are needed.
A possible mechanism, seen in rats
A 2023 study in Molecules offers a clue about why vitamin D might help. Researchers removed the ovaries from rats to mimic menopause, then tracked what happened to vaginal tissue with and without vitamin D treatment.
The rats developed the rodent version of GSM. Their vaginal pH rose, their Lactobacillus levels dropped, and their vaginal and uterine tissue lost weight and thickness. At the cellular level, the rats made less of three proteins tied to tissue health: PCNA, which drives cell growth, and E-cadherin and occludin, which hold epithelial cells together to form a barrier.
Vitamin D treatment reversed several of these changes. It lowered vaginal pH, increased Lactobacillus, and boosted the vaginal lining’s thickness. It also raised PCNA, E-cadherin, and occludin levels in both the rats and human vaginal cells grown in a lab dish. In plain terms, vitamin D appeared to help vaginal cells multiply and stick together more effectively, rebuilding a tissue barrier that estrogen loss had broken down.
This is a plausible biological explanation for how vitamin D might work in women. However, rat vaginal tissue and human vaginal tissue don’t always respond the same way, and a mechanism that works in a lab dish doesn’t guarantee a benefit in real patients.
What the broader evidence shows
A 2025 systematic review and meta-analysis, published in the International Journal of Gynecology & Obstetrics by Youssef and colleagues, pulled together the human evidence available so far. The team combined data from eight randomized controlled trials covering 608 postmenopausal women, 222 of whom received vitamin D.
The results were mixed:
- Oral vitamin D showed no significant improvement in the vaginal health index and only slightly improved vaginal pH.
- Topical vitamin D did show a significant improvement in the vaginal health measure, along with a rise in the percentage of healthy superficial vaginal cells. On sexual function, topical vitamin D helped with arousal specifically, but not with other domains evaluated.
The review’s authors were blunt about the bottom line: vitamin D alone is not a sufficient alternative to existing treatments, particularly topical estrogen.
Why the evidence falls short for genitourinary syndrome
Several problems weaken confidence in even the positive findings. Most subgroups showed substantial statistical heterogeneity, meaning the trials disagreed with each other more than chance would predict. Sample sizes were small. Studies used different doses, forms, and durations of vitamin D, which makes it hard to know what actually “works.” No trial tested vitamin D in breast cancer survivors, the group most likely to need a nonhormonal option. Most studies never measured women’s baseline vitamin D levels, so nobody knows whether vitamin D helps everyone or mainly women who started out deficient.
Where this leaves women considering vitamin D
Vitamin D is not a substitute for vaginal estrogen when estrogen is a safe option. But for women who can’t or won’t use hormonal treatment, and who don’t have access to prescription nonhormonal drugs like ospemifene or prasterone, vitamin D (especially in topical form) remains a low-risk option worth discussing with a physician.
Nobody should start any new treatment for genitourinary syndrome of menopause without medical guidance, vitamin D included. A doctor can check vitamin D levels, rule out other causes of symptoms, and help weigh the modest, uncertain benefits this research shows against other options. GSM is common, treatable, and worth talking about. The more women raise it with their doctors, the faster researchers will fill in the gaps that studies like these leave open.
To learn more about hormonal options to treat menopause symptoms, visit our page on Hormones for Menopause.
