Vitamin D and fertility

Infertility is a complex disorder with important medical and psychosocial aspects that affects about 15% of couples. Vitamin D is also known as “the vitamin of the sun”. It is produced in the skin in response to sun exposure, and can also be eaten through food and supplements. While most of the people have heard about the benefits and vitality of vitamin D in skeletal health, few know that vitamin D levels can affect fertility of both men and women.

What is vitamin D3?

Vitamin D3 (cholecalciferol) is the primary form of vitamin D in the body. It is the form that is produced on the skin and can be found in certain foods and supplements. Although there are other forms of vitamin D, such as vitamin D2 (ergocalciferol), studies have shown that our body metabolizes vitamin D3 more effectively than vitamin D2. If we were exposed to sun adequately, no one would have a deficiency in vitamin D. However, most people do not have enough sun exposure to maintain a normal vitamin D level throughout the year.

Vitamin D, fertility and pregnancy

Vitamin D has been associated with a variety of health benefits. Results from clinical studies indicate that vitamin D deficiency is very common in pregnant and breastfeeding women and is associated with many health problems. There is some evidence that in addition to hormone steroid hormones, which are the regulators of reproduction, vitamin D also regulates reproductive processes in women and men.

For women trying to conceive, it seems to be associated with better fertility, as well as with a healthy pregnancy. Although data on vitamin D and fertility are not consistent, several studies have found that vitamin D levels in the blood above 30 ng/mL, are associated with the highest rates of pregnancy. Studies also showed that women who had normal vitamin D levels were four times more likely to become pregnant through IVF compared to those who had low levels of vitamin D. Studies have linked vitamin D deficiency during pregnancy, with increased risk of premature delivery, gestational diabetes, pre-eclampsia (very high blood pressure during pregnancy) and bacterial vaginosis.

As for men, vitamin D levels appear to be related to spermatogenesis, sperm quality and hypogonadism. It is also associated with the levels of androgens, as it has been shown that taking vitamin D can increase testosterone levels.

Vitamin D supplements

Considering the multiple side effects of vitamin D deficiency in various aspects of health, vitamin D supplementation is of great importance. Meta-analysis of studies has shown that vitamin D supplementation during pregnancy is safe and improves vitamin D and calcium status, thus protecting health. There are no specific guidelines for vitamin D supplementation for women or men who have endocrine disorders and infertility. The current guidelines for vitamin D are 400 to 800 IU daily intake, and 1000 IU daily may be needed if there is a deficiency.