For many women navigating fertility planning or delayed motherhood, ovarian reserve often becomes the focal point of concern. Yet, one silent factor continues to slip under the radar – vitamin D deficiency.
Despite India’s abundant sunlight, low vitamin D levels are alarmingly common and increasingly linked to declining ovarian reserve, hormonal imbalance, and compromised fertility outcomes. Emerging evidence now positions vitamin D not just as a supporting nutrient, but as an active regulator of ovarian health and reproductive potential.
Why Vitamin D Is More Than A Bone Nutrient
“Vitamin D deficiency is still largely overlooked when it comes to ovarian reserve and reproductive planning,” says Dr. Nidhi Saluja, Centre Clinical Director at Indira IVF, Gurugram. She explains that vitamin D receptors are present in the ovaries, endometrium, and placenta, underscoring its direct role in follicle development, hormone regulation, and implantation. “It’s not just an associated factor. It can directly affect how the ovaries function.”
This biological connection is echoed by Dr. Onkar Swami, Senior Vice-President–Medical Services at Alembic Pharmaceuticals. He notes, “Vitamin D receptors are present in ovarian tissue, where the vitamin influences follicle development, hormone production, and ovarian aging.” Together, these findings challenge the traditional view of vitamin D as merely a bone-health nutrient.
The Link Between Vitamin D And Ovarian Reserve
Ovarian reserve is commonly assessed through anti-Mullerian hormone (AMH) levels and antral follicle count (AFC). According to Dr. Swami, “Multiple studies have found that women with low vitamin D levels tend to have lower AMH values and higher rates of diminished ovarian reserve.” Meta-analyses and ART-based studies further reinforce that vitamin D–replete women often show healthier ovarian reserve profiles.
Clinically, Dr. Saluja observes that low vitamin D frequently coexists with poor ovarian response, especially in women with PCOS. “Women with adequate vitamin D often show better ovarian markers, particularly in conditions where hormonal and metabolic imbalances already challenge fertility,” she adds.
Beyond Ovarian Reserve: Hormones, Immunity, And Implantation
Vitamin D’s influence extends well beyond egg count. “It supports embryo quality and endometrial receptivity by regulating immune function at the maternal-fetal interface,” explains Dr. Saluja, highlighting its role in implantation and early pregnancy success.
From a broader gynaecological perspective, Dr. Sushma Tomar, Consultant at Fortis Hospital, Kalyan, points out that deficiency often presents alongside irregular cycles, poor ovulation, and low AFC. “Declining ovarian reserve is very common in infertility with vitamin D3 deficiency because it helps in folliculogenesis and increases antral count,” she says.
Dr. Tomar also emphasises vitamin D’s role in AMH gene expression, noting that deficiency is prevalent in women with PCOS, obesity, and menopausal changes – factors already linked to reproductive decline.
Why Indian Women Are Especially Vulnerable
Despite plentiful sunlight, vitamin D deficiency remains widespread in India. Dr. Swami notes that nearly half to two-thirds of infertile women are vitamin D-deficient. Factors such as darker skin pigmentation, indoor lifestyles, sunscreen use, and dietary gaps all contribute to poor absorption.
Alarmingly, severe deficiency may also trigger immune-mediated ovarian dysfunction. “Indian studies show increased ovarian autoantibodies in women with severe deficiency,” Dr. Swami explains, pointing to a potential autoimmune pathway affecting ovarian health.
Screening, Supplementation, And Fertility Care
With growing evidence, vitamin D testing is gaining recognition as part of fertility evaluation. “Given its low cost, safety, and emerging reproductive relevance, correcting deficiency may offer a simple but meaningful way to support reproductive health,” says Dr. Swami.
Dr. Tomar adds that sunlight exposure, dietary changes, oral supplementation, or injectable vitamin D3 can significantly improve symptoms and support fertility treatment outcomes.
Vitamin D deficiency may be one of the most under-recognised yet modifiable factors influencing ovarian reserve in women today. As fertility timelines shift and ovarian ageing becomes a growing concern, early screening and correction of vitamin D levels could play a crucial role in preserving reproductive potential and improving outcomes – naturally and through assisted reproduction.
