From: Vitamin D and assisted reproduction technologies: current concepts
Author, year, [reference #] | Country | Study design | COH | Sample size | Biological sample(s) used for 25(OH)D assessment | Main Outcomes | Statistical analysis used for cycle outcome assessment | Main finding(s) | Main confounding factors considered in the analysis |
---|---|---|---|---|---|---|---|---|---|
Potashnik et al., 1992 [47] | Israel | Prospective cohort | Long agonist protocol | 10 | Serum; follicular fluid (from “one large follicle”) | Vitamin D and metabolites’ levels throughout COH | Paired t-test | 1,25(OH)2D increased at the end of stimulation. No changes observed for 25(OH)D, 24,25(OH)2D | None |
Ozkan et al., 2010 [38] | USA | Prospective cohort | Long agonist protocol | 84 | Serum; follicular fluid (pooled from follicles ≥14 mm) | CPR | Multivariate logistic regression | FF levels of 25(OH)D act as positive independent predictor of CPR | Age |
Race | |||||||||
BMI | |||||||||
Embryos transferred (n) | |||||||||
Anifandis et al., 2010 [39] | Greece | Retrospective cohort | Short agonist protocol | 101 | Serum; follicular fluid (pooled from all follicles) | Glucose levels in follicular fluid; embryo quality; CPR | X2-test | Higher FF levels of 25(OH)D are associated with lower FF glucose levels and with lower CPR | Age |
BMI | |||||||||
Oocytes retrieved (n) | |||||||||
Aleyasin et al., 2011 [40] | Iran | Prospective cohort | Long agonist protocol | 82 | Serum; follicular fluid (pooled from follicles ≥14 mm after oocyte isolation) | CPR | Multivariate logistic regression | No significant association between FF or serum levels of 25(OH)D and CPR | Variables showing p value ≤ 0.2 on univariate logistic regression |
Rudick et al., 2012 [41] | USA | Retrospective cohort | Long agonist; antagonist; microdose flare protocol | 188 | Serum | CPR | Multivariate logistic regression | Opposite relation between 25(OH)D levels and IVF outcomes by race: higher levels of 25(OH)D associated with higher CPR in non-Hispanic whites and with lower CPR in Asians | Age |
BMI | |||||||||
Embryos transferred (n, quality) | |||||||||
Poor ovarian reserve | |||||||||
Firouzabadi et al., 2014 [34] | Iran | Prospective cohort | Long agonist protocol | 221 | Serum; follicular fluid | Chemical pregnancy rate | Kruskal-Wallis H test | No significant association between FF or serum levels of 25(OH)D and CPR | None |
Rudick et al., 2014 [42] | USA | Retrospective cohort | Egg donation recipients | 99 | Serum | CPR, LBR | Multivariate logistic regression | Higher 25(OH)D levels associated with higher CPR and LBR | Recipient age |
Recipient BMI | |||||||||
Embryos transferred (n, quality) |