A recent study is the largest to date that examines how vitamin D affects fertility in women who are undergoing fertility treatment, namely IVF. For decades scientists have known that vitamin D is essential for mammalian reproduction, but its role in human fertility specifically has not been as well studied.
The study evaluated pregnancy outcomes for 335 women who attended a fertility clinic in Milan in 2012. Researchers measured serum vitamin D levels up to 90 days before their embryo transfer. Out of the 335 women, 154 had vitamin D deficiency – the embryo implantation rate for this group was just 13% compared to 21% for women who have sufficient or higher levels of vitamin D in their serum. The rates of successful pregnancy were also increased for women with higher levels of vitamin D.
This analysis was adjusted to account for other factors, such as age, ethnicity, parity, body mass index, fertility duration, number of retrieved oocytes, number of transferred embryos, study period, and the presence of at least one top-quality embryo.
The authors stated that “it can be concluded that vitamin D insufficiency negatively affects clinical pregnancy rate in women undergoing IVF”. However, they also warn that this does not establish a causal relationship between low vitamin D and general infertility – more randomised and controlled trials would be required to determine whether vitamin D definitely plays a supporting role in the chances of both pregnancy and infertility.
When trying to conceive, whether naturally or while undergoing fertility treatment, it is important to pay close attention to diet and lifestyle to increase your chances of conception and to improve the chances of a healthy baby and comfortable pregnancy. A balanced diet should provide sufficient vitamin D, but some people may need to take supplements to reach optimum levels. Speak to your doctor before taking any supplements, either before or during pregnancy.