Optimizing Fertility: The Role of Vitamin D in Ovarian Reserve and Egg Quality

Vitamin D, commonly known as the "sunshine vitamin," is an essential nutrient that plays a crucial role in maintaining overall health and well-being. Emerging research suggests that vitamin D may also have an important impact on ovarian health and reproductive function. Unfortunately at first glance, the research on the impact of Vitamin D and ovarian reserve isn’t as straightforward as we would like. Part of this comes from the fact that we know vitamin D is often low in women with PCOS, women with autoimmune diseases and women with elevated BMI. All of which are common reasons why women are seeking fertility care in the first place. This also means that unless the study has explicitly controlled for each of these previously mentioned factors, it can be hard to determine the true association between vitamin D and fertility. The other issue we often face in research when evaluating specific factors that impact ovarian reserve, is that researching ovarian failure is often determined retrospectively, meaning that we aren’t always aware that women are having ovarian failure until they are no longer candidates for fertility care.

So what do we actually know about the role of Vitamin D and fertility and how does this impact you?

I’m glad you asked! Let’s give in!

Observational trials have found that vitamin D status can be low in unsuccessful fertility cycles and overall is seen to be lower in women with established infertility. This means that if you are currently struggling to conceive, it may be worth asking your doctor to test your vitamin D levels. What is also interesting about the role vitamin D plays in fertility care is that although the association between vitamin D and AMH levels has not been found to have a significant impact in observational trials, we do see that in interventional trials (trials were vitamin D was given as a therapy), vitamin D may improve AMH levels in women with declining ovarian reserve - making it the ONLY supplemental intervention that changes this biomarker of fertility status.

To date, there are two main trials that noticed that  the supplementation of vitamin D improved AMH levels in women with low ovarian reserve.

The first study by Naderi (2018) dosed Vitamin D at 50,000IU weekly (NOT DAILY) for 3 consecutive months. Researchers found that over the 3 months, vitamin D and AMH levels improved significantly.

The second study by Dennies et al (2017) administered a single dose of 50,000IU of vitamin D to women who were identified as infertile who also had vitamin D levels below 75 nmol/L. This single dose caused a statistically significant rise not only in vitamin D levels but an acute rise in AMH levels. The mean increase of AMH seen by women in this study was 12.9%!

Although there are still few trials on this particular topic, given the significant impact vitamin D has in fertility in general, women with established vitamin D deficiencies should be candidates for vitamin D treatment in the context of their fertility care. So whether you are trying naturally or you are gearing up for IVF, if you have a vitamin D deficiency, treating your vitamin D deficiency before trying to conceive or before your next round of IVF is critical in improving your chances of success!

Vitamin D also influences other important factors in your fertility care including:

Vitamin D and Egg Quality

Vitamin D may contribute to improving the quality of eggs produced by the ovaries. A study by Rudick et al. (2012) found that women with higher vitamin D levels had a higher percentage of mature eggs retrieved during assisted reproductive techniques. This suggests that sufficient vitamin D may positively impact egg maturation and overall egg quality.

Anti-Inflammatory Effects

Vitamin D has also been shown to possess anti-inflammatory properties. Chronic inflammation in the ovaries can negatively affect ovarian reserve. Adequate vitamin D levels may help reduce inflammation in ovarian tissues, potentially preserving ovarian reserve. Further research is needed to fully understand this mechanism but is something to consider in patients suffering from infertility. 

Hormonal Regulation

Vitamin D is known to influence hormone regulation in the body. Researchers believe it may impact follicle-stimulating hormone (FSH) levels, which play a crucial role in the maturation of eggs in the ovaries. Maintaining optimal FSH levels is essential for maintaining a healthy ovarian reserve.

Fertility Treatment Outcomes

Research suggests that women with sufficient vitamin D levels may have improved outcomes during fertility treatments such as in vitro fertilization (IVF). Higher vitamin D levels have been associated with higher pregnancy rates and successful embryo implantation.

While research into the impact of vitamin D on ovarian reserve is still ongoing, emerging evidence suggests that maintaining adequate vitamin D levels may have a positive influence on egg quality, ovarian function, and fertility outcomes. Asking your doctor to test and RETEST your vitamin D levels if you are deficient can be an important goal in your fertility care.

References: 

Dennis, N. A., Houghton, L. A., Pankhurst, M. W., Harper, M. J., & McLennan, I. S. (2017). Acute Supplementation with High Dose Vitamin D3 Increases Serum Anti-Müllerian Hormone in Young Women. Nutrients, 9(7). https://doi.org/10.3390/nu9070719

Drakopoulos, P., van de Vijver, A., Schutyser, V., Milatovic, S., Anckaert, E., Schiettecatte, J., Blockeel, C., Camus, M., Tournaye, H., & Polyzos, N. P. (2017). The effect of serum vitamin D levels on ovarian reserve markers: A prospective cross-sectional study. Human Reproduction (Oxford, England), 32(1), 208–214. https://doi.org/10.1093/humrep/dew304

Jukic, A. M. Z., Baird, D. D., Wilcox, A. J., Weinberg, C. R., & Steiner, A. Z. (2018). 25-Hydroxyvitamin D (25(OH)D) and biomarkers of ovarian reserve. Menopause (New York, N.Y.), 25(7), 811–816. https://doi.org/10.1097/GME.0000000000001075

Naderi, Z., Kashanian, M., Chenari, L., & Sheikhansari, N. (2018). Evaluating the effects of administration of 25-hydroxyvitamin D supplement on serum anti-mullerian hormone (AMH) levels in infertile women. Gynecological Endocrinology: The Official Journal of the International Society of Gynecological Endocrinology, 34(5), 409–412. https://doi.org/10.1080/09513590.2017.1410785

Rudick, B. J., Ingles, S. A., Chung, K., Stanczyk, F. Z., & Paulson, R. J. (2012). 

Shapiro, A. J., Darmon, S. K., Barad, D. H., Gleicher, N., & Kushnir, V. A. (2018). Vitamin D levels are not associated with ovarian reserve in a group of infertile women with a high prevalance of diminished ovarian reserve. Fertility and Sterility, 110(4), 761-766.e1. https://doi.org/10.1016/j.fertnstert.2018.05.005

About the Author: Meet Dr. ZenAlissia Zenhausern- Pfeiffer, NMD, FABNE, (commonly known by her patients as Dr. Zen), is a licensed naturopathic doctor board certified in naturopathic endocrinology and the founder of NMD Wellness of Scottsdale, a premier naturopathic medical practice that focuses on helping women to take a proactive approach to their hormone and fertility health. Dr. Zen has been featured as a lead expert in Forbes, Shape Magazine, and Instyle and is deeply passionate about bridging the gap between traditional and natural medicine in the world of fertility. She works with a variety of hormone related issues including PCOS, endometriosis and unexplained infertility. Her goal is to help more women get back into the driver’s seat of their own health to make lasting transformational changes to their health to bring more cute and adorable babies into this world. Read More About Dr. Zen...