vitamin DResearchers have determined a connection between vitamin D levels in women undergoing in-vitro fertilization (IVF) and IVF success. According to the study, published in CMAJ Open, women with adequate vitamin D levels are more likely to conceive with IVF than women with lower than adequate levels. The body is prepared to naturally produce more than enough vitamin D when the skin comes in contact with sunlight.

Deficiency of vitamin D levels is common in women in the United States, especially during the winter when women tend to stay inside or use clothing to protect skin from cold weather and the environment. Extensive use of sunscreen prior to going out in the sun in summer months also affects vitamin D production.

The study completed in Toronto, involved 173 women. More than 50% of the women in the study suffered from low vitamin D levels. Overweight women tend to be at increased risk of vitamin D deficiency than normal weight women, according to study authors and a study published in PLoS Medicine.

Women with adequate levels of vitamin D, based on serum testing, achieved clinical pregnancy in more than 52% of cases. Women with inadequate levels were significantly less successful with a success rate of about 35%. Researchers believe serum vitamin D testing before IVF treatment could be enough to improve success rates in most clinical settings. Vitamin D supplementation is extremely affordable and with a 20% gap between women with adequate vitamin D levels and women with inadequate vitamin D levels taking a vitamin D supplement could theoretically mean the difference between successful IVF and unsuccessful IVF for many women.

Dr. Kimberly Lui believes vitamin D supplementation could be a turning point for some women. “We know that [women] are prone to vitamin D insufficiency, especially during the winter months and this study suggests that vitamin D supplementation could provide an easy and cost-effective means for improving pregnancy rates…we are always looking at ways to improve a patient’s success with fertility treatments; this study gives us an opportunity for further research so we can continue to help our patients.”

Source: Kimberley Garbedian, Miranda Boggild, Joel Moody, and Kimberly E. Liu. Effect of vitamin D status on clinical pregnancy rates following in vitro fertilization. doi: 10.9778/cmajo.20120032.