Vitamin D Enhances Fertility
Vitamin D for implantation and continuation of a pregnancy
Unfortunately, and surprisingly, vitamin D deficiency is very common, affecting about 50% of New Zealand adults. Vitamin D is needed by the body to create sex hormones which in turn affects ovulation and implantation and may help prevent miscarriage. Research has shown that Vitamin D supplementation by both men and women may help couples trying to conceive.
Good levels of vitamin D are associated with successful fertility
A 2014 study found that Women who had sufficient levels of vitamin D were twice as likely to conceive twice as likely to conceive as their counterparts with vitamin D deficiency. The authors said, “We found that women who had sufficient levels of vitamin D were more likely to produce high-quality embryos and more likely to become pregnant than women who were deficient in vitamin D.” This study was repeated in another IVF center, which confirmed a four-fold difference in pregnancy rates between vitamin D replete and deficient women. In another study looking at the recipients of donor eggs, vitamin D levels in the recipients were associated with clinical pregnancy, emphasizing that the critical role of vitamin D in pregnancy may be within the uterus. Though more research is needed, it appears that vitamin D levels are associated with IVF success and that it’s most important role in reproduction may be at the uterine lining.
A 2015 clinical trial found that males with low serum levels of vitamin D have correspondingly lower pregnancy rates. This demonstrates the importance of both couples both taking a supplement to ensure Vitamin D levels are high.
4000 ug of Vitamin D per day is recommended in pregnancy
4,000 IU of vitamin D daily had the greatest benefits in preventing preterm labor/births and infections in this 2013 clinical trial. The average prenatal vitamin only contains 400 IU of vitamin D, so additional supplementation should be taken daily. In my clinic, I use a practitioner only Vitamin D spray ( $32.70 ). It’s an easy way to top up during the day versus taking more pills.
And for those who like to know the science behind Vitamin D in the reproductive world….
D3 is able to affect many different types of cells in different organs in the body. The way it does this is by turning genes within that cell, “on and off.” In other words, vitamin D affects the way a cell carries out its function, and it can control the growth or the death of that cell.
In the world of reproduction, the importance of vitamin D was initially shown in experiments with mice. Mice who are either deficient in vitamin D or who lack the vitamin D receptor, demonstrated underdevelopment of the uterus and inability to form normal mature eggs, resulting in infertility. If pregnancy is achieved, the fetuses of these mice showed impaired growth. Reproduction is normalised in mice with vitamin D supplementation.
In humans, the vitamin D receptor is present in many organs, including the testes, ovary, uterus, and placenta. The active form of vitamin D (calcitriol) has many roles in female reproduction. Bound to its receptor, calcitriol is able to control the genes involved in making estrogen. The uterine lining produces calcitriol in response to the embryo as it enters the uterine cavity, shortly before implantation. Calcitriol controls several genes involved in embryo implantation. Once a woman becomes pregnant, the uterus and placenta continue to make calcitriol, which helps organise immune cells in the uterus, so that infections can be fought without harming the pregnancy. Poor vitamin D status has been associated with certain pregnancy complications such as gestational hypertension and diabetes. Women about to undergo in vitro fertilization (IVF) can provide valuable insight into the role of vitamin D, since it is possible to examine each aspect of reproduction, from egg development to implantation of the embryo.