Women with sufficient vitamin D levels who had undergone assisted reproductive treatment had higher live birth rates than similar women who were vitamin D-insufficient or deficient, according to a systematic review and meta-analysis recently published in Human Reproduction.
“The biological plausibility that vitamin D plays an important role in implantation has led research groups to investigate the importance of vitamin D in patients undergoing assisted reproductive treatment,” Justin Chu, MBChB, MRCOG, academic lecturer, Institute of Metabolism and Systems Research, University of Birmingham, United Kingdom, and colleagues wrote. “Some studies have found that replete concentrations of vitamin D lead to an increase in clinical pregnancy and live birth rates. However, others have found conflicting evidence suggesting that vitamin D has no effect on the outcome of assisted reproductive treatment.”
Researchers summarized the available evidence by reviewing 11 studies with 2,700 women who underwent either in vitro fertilization, intracytoplasmic sperm injection and/or frozen embryo transfer and had their vitamin D status checked either through follicular fluid assay or blood serum. Primary outcome was live birth rates according to vitamin D status, and secondary outcomes were clinical pregnancy and biochemical pregnancy rates.
Chu and colleagues found that when comparing women who were vitamin D replete vs. women were insufficient or deficient:
- live births were more likely (OR = 1.33; 95% CI, 1.08–1.65);
- clinical pregnancies were more likely (OR = 1.46; 95% CI, 1.05–2.02); and
- biochemical pregnancies were more likely (OR = 1.34; 95% CI, 1.04–1.73).
Despite the findings, it is premature to suggest women undergoing assisted reproductive treatments take vitamin D, Chu said in a press release.
“Women who want to achieve a successful pregnancy should not rush off to their local pharmacy to buy vitamin D supplements until we know more about its effects,” he said. “It is possible to overdose on vitamin D and this can lead to too much calcium building up in the body, which can weaken bones and damage the heart and kidneys.” – by Janel Miller
The authors report no relevant financial disclosures.