How do vitamin D level affect in vitro fertilization outcomes?

This study investigated if vitamin D (VitD) levels affect fertility outcomes after in vitro fertilization (IVF). They found that VitD levels did not seem to be associated with fertility outcomes after IVF.

Infertility is a common problem worldwide. Assisted reproductive technology (ART) has improved fertility outcomes for many couples. In vitro fertilization (IVF) or intracytoplasmatic sperm injection are ARTs. IVF involves fertilizing an egg (oocyte) with a sperm in the lab and then implanting the embryo in the uterus. ICSI involves injecting a sperm cell directly into the egg.

Fertility outcomes after IVF/ICSI have improved over the years. A lot of research has focused on the role of diet in infertility. Vitamin D (VitD) is an important nutrient. It is a hormone produced by the skin in response to ultraviolet light. VitD is important in female reproduction. It helps regulate cell growth in the ovary and uterine lining. Low VitD levels are common in infertile couples. It is unclear if VitD levels are associated with fertility outcomes after IVF/ICSI. 

This study analyzed 14 clinical studies in couples undergoing IVF. This included 4,382 participants overall. All studies investigated VitD levels. 

Women who had normal vitD levels (30 ng/ml or higher) had a 32% higher chance of a clinical pregnancy and a 22% higher chance of a live birth compared to women with low vitD levels. However, these results were not statistically significant. No significant association was found between levels of vitD and miscarriage rate.

The authors concluded that VitD levels did not seem to be associated with fertility outcomes in couples undergoing IVF/ICSI.

There was a lot of variability in the data. This made it difficult to compare findings. VitD levels fluctuated seasonally. This could also affect fertility outcomes. In some studies, black and Asian women had lower vitD than other ethnic groups. All these factors make it difficult to compare results. 

If you have any concerns regarding infertility and vitamin D levels, please consult with your doctor.