Vitamin D and assisted reproduction technologies: current concepts

Area of Science:

• Reproductive Endocrinology
• Nutritional Science
• Infertility Research

Background:

• Vitamin D plays a role in reproductive functions for both genders.
• The relationship between vitamin D status and Assisted Reproduction Technologies (ART) outcomes requires comprehensive analysis.
• Vitamin D deficiency is prevalent and correctable with inexpensive supplementation.

Purpose of the Study:

• To systematically review and meta-analyze clinical studies on vitamin D status in patients undergoing ART.
• To evaluate the association between vitamin D levels and ART cycle outcomes.
• To identify gaps in research, particularly regarding male partners' vitamin D status.

Main Methods:

• Systematic review and meta-analysis of seven studies on women undergoing controlled ovarian hyperstimulation (COH) for ART.
• Analysis of vitamin D deficiency prevalence (serum 25-hydroxyvitamin D <20 ng/ml).
• Meta-analysis of data from three studies to calculate the risk ratio for clinical pregnancy.

Main Results:

• High prevalence of vitamin D deficiency in women undergoing COH (21-31% in Western countries, 75-99% in Iranian studies).
• Vitamin D deficiency was associated with a non-statistically significant lower likelihood of clinical pregnancy (RR 0.89, 95% CI 0.53-1.49).
• No studies were found assessing vitamin D status in male partners undergoing ART.

Conclusions:

• Insufficient evidence currently supports routine assessment of vitamin D status for predicting ART clinical pregnancy rates.
• Conflicting results may stem from confounders and small sample sizes in existing studies.
• Larger cohort and randomized controlled studies are needed to clarify the role of vitamin D in ART outcomes.