A new study published in the journal Human Reproduction found that there is a relationship between vitamin D levels and fertility treatment success rates from assisted reproductive technology. The researchers concluded that women with sufficient levels of vitamin D have higher live birth rates after undergoing fertility treatment with assisted reproductive technology than women with low vitamin D levels.
The study was a systematic review and meta-analysis of 11 published studies that looked at an association between vitamin D levels and assisted reproductive technology outcomes. The 11 studies combined included 2700 women who underwent IVF, frozen embryo transfer, or both. All of the women had vitamin D levels checked by blood blood tests. Vitamin D levels greater than 75 nmol/L of blood were considered sufficient, 50-75 nmol/L were considered insufficient, and less than 50 nmol/L were deficient.
Women with sufficient vitamin D levels were 34% more likely to have a positive pregnancy test, 46% more likely to have a clinical pregnancy (fetal heart beat seen on ultrasound), and 33% more likely to have a live birth than women with insufficient or deficient vitamin D status. Overall, in the study, only 26% of women had sufficient vitamin D levels. 45% had insufficient levels and 35% were deficient.
The majority of our vitamin D supply is generated in our skin after sun exposure. That means that women living in colder climates are at higher risk for having low vitamin D levels. Women with darker skin, women who wear clothes covering the majority of their skin, women who routinely use sunscreen, and women who don’t spend much time outdoors are also at risk of having low levels.
For those women who are at higher risk of having low vitamin D levels and struggling with infertility, you may want to ask your physician to have a vitamin D level checked. According to this study, it may be beneficial to optimize your vitamin D level, especially when undergoing fertility treatment.