Characterizing the influence of vitamin D levels on IVF outcomes.
BACKGROUND
Vitamin D plays a role in reproductive capacity. Recently, several investigators have demonstrated higher IVF pregnancy rates in vitamin D replete women. The objective of this study was to validate these findings and to further elucidate the role of vitamin D in reproduction among a diverse group of women.


METHODS
This was a retrospective cohort study in an academic tertiary care center of 188 infertile women undergoing IVF. Serum levels of vitamin D (25OH-D) were measured in previously frozen serum samples. The main outcome measure was clinical pregnancy, defined as sonographic presence of a heartbeat following IVF.


RESULTS
The relationship between vitamin D status and pregnancy rates differed by race (P < 0.01). Among non-Hispanic whites, pregnancy rates declined with progressively lower levels of vitamin D, while in Asians, the reverse was true. Adjusting for age and number and quality of embryos transferred among non-Hispanic whites, the odds of pregnancy were four times higher in vitamin D replete versus deficient patients. Live birth rates mirrored pregnancy rates. Vitamin D status was not associated with ovarian stimulation parameters or with markers of embryo quality.


CONCLUSIONS
Vitamin D deficiency is associated with lower pregnancy rates in non-Hispanic whites, but not in Asians, possibly due to their lower IVF success rates. Vitamin D deficiency was not correlated with ovarian stimulation parameters or with markers of embryo quality, suggesting its effect may be mediated through the endometrium.
Center for Women's Reproductive Health, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Columbia University, New York, NY 10019, USA. briana.rudick@gmail.com
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Stanczyk
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D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000046:Academic Medical Centers; D000328:Adult; D001213:Asian; D002112:Calcifediol / Q000097:blood*; D015331:Cohort Studies; D010064:Embryo Implantation; D004717:Endometrium / Q000503:physiopathology; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000097:blood / Q000150:complications* / Q000208:ethnology / Q000628:therapy*; D050498:Live Birth; D015141:Los Angeles / Q000453:epidemiology; D010044:Outpatient Clinics, Hospital; D011247:Pregnancy; D018873:Pregnancy Rate / Q000208:ethnology; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014808:Vitamin D Deficiency / Q000150:complications* / Q000453:epidemiology / Q000208:ethnology / Q000503:physiopathology; D044465:White People
D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol