Does vitamin D supplementation affect ovarian reserve markers in women with infertility associated with diminished ovarian reserve?

This study evaluated the effects of vitamin D supplementation on ovarian reserve markers in women with infertility due to reduced ovarian reserves and vitamin D deficiency. The study showed possible beneficial effects on ovarian reserve markers with vitamin D supplementation in these women.

Ovarian reserve refers to the number of healthy, immature eggs found in a woman’s ovaries. As a woman ages, this number becomes reduced, and this is known as a diminished ovarian reserve (DOR). DOR is recognized as a cause of lowered fertility. DOR indicators include changes in serum anti-Mullerian hormone (AMH), serum follicle-stimulating hormone (FSH), and antral follicle count (AFC). Vitamin D has many important roles including some that relate to reproduction. In addition to being important for the developing follicle, it may influence AMH and progesterone production, and sensitivity to FSH.

Vitamin D is made in the skin by ultraviolet-B radiation from sunlight. This process results in the production of 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxy vitamin D (1,25(OH)D). Vitamin D deficiency can be significant to women of reproductive age. Whether or not vitamin D has the ability to influence ovarian reserve remains unclear and requires further investigation.

The study included 62 women with DOR and 25(OH)D deficiency. Patients were unable to achieve pregnancy after 12 months of regular sexual intercourse. All patients had partners with normal semen parameters and no other gynecological issues. Levels of serum AMH, FSH, 25(OH)D, 1,25(OH)D, calcium, phosphate, alkaline phosphatase, and parathormone (blood markers of vitamin D abnormalities) were assessed in patients before and after supplemental vitamin D was given. Patients received 300,000 international units (IU) of vitamin D ampules.

There was a statistically significant increase in AFC, AMH, 25(OH)D, 1,25(OH)D, phosphate, and calcium levels following supplementation with vitamin D. There was a statistically significant decrease in FSH and alkaline phosphatase levels after vitamin D supplementation.

The study found that vitamin D supplementation led to increased AFC and AMH levels and a decrease in the level of FSH in women with infertility and may provide some benefits for fertility treatment.

The study design did not allow for patient randomization and the number of patients included was small. Additional factors that would influence the results such as dietary habits and clothing styles were not considered. Further studies are needed.