Table 1.
Studies examining the relationship between vitamin D levels and ART outcomes
| Study | n | Vitamin D status | % of patients | Fertilization (%) | Implantation (%) | CP per cycle (%) | CP per ET (%) | % CP improvement |
|---|---|---|---|---|---|---|---|---|
| Prospective cohort | ||||||||
| Aleyasin et al. [67] 2011 Iran |
82 | Deficient | 98.8 | 79 | 9.6 | – | – | CP not reported |
| Insufficient | 1.2 | 67.8 | 13 | – | – | |||
| Replete | 0 | 68.3 | 15.9 | – | – | |||
| P-value | 0.274 | 0.857 | – | – | ||||
| Anifandis et al. [68] 2010 Greece |
86 | Deficient | 30.7 | – | – | – | 40 | Deficient→Replete: −24.2 Insufficient→Replete: −22.3 |
| Insufficient | 48.5 | – | – | – | 38.1 | |||
| Replete | 20.8 | – | – | – | 15.8 | |||
| P-value | – | – | – | <0.05 | ||||
| Firouzabadi et al.a [66] 2012 Iran |
180 | Deficient | 22.6 | 43.17 | 17.33 | 31.1 | – | Deficient→Replete: −25.7 Insufficient→Replete: −58.1 |
| Insufficient | 70.1 | 53.37 | 15.26 | 63.5 | – | |||
| Replete | 7.2 | 58.77 | 18.75 | 5.4 | – | |||
| P-value | 0.054 | 0.579 | 0.094 | – | ||||
| Garbedian et al.b [72] 2013 Canada |
173;162e | Insufficientf | 55.0 | – | 25.6 | 34.7 | 37.9 | 16.8 |
| Sufficient | 45.1 | – | 34.5 | 52.5 | 54.7 | |||
| P-value | – | 0.06 | <0.001 | |||||
| Ozkan et al.c [69] 2010 USA |
84 | Lowest tertile | 27 % deficient; 36 % insufficient; 37 % replete | – | 11 | <0.001 | 20 | N/A |
| Middle tertile | – | 12 | – | 21 | ||||
| Highest tertile | – | 26 | – | 49 | ||||
| P-value | – | 0.041 | – | 0.029 | ||||
| Retrospective cohort | ||||||||
| Polyzos et al.d [73] 2014 Belgium |
368 | Deficient | 65 | 78.7 | – | – | 41 | 13 |
| Not deficient | 35 | 78.2 | – | – | 54 | |||
| P-value | 0.81 | – | – | 0.015 | ||||
| Rudick et al. [70] 2012 USA |
188 | Deficient | 21 | 74 ± 17 | 16 ± 27 | 36 | – | Deficient→Replete: 7 Insufficient→Replete: 5 |
| Insufficient | 37 | 71 ± 23 | 18 ± 27 | 41 | – | |||
| Replete | 42 | 68 ± 25 | 19 ± 26 | 43 | – | |||
| P-value | 0.79 | 0.38 | 0.48 | – | ||||
| Rudick et al. [71] 2014 USA |
99 | Deficient | 26 | – | – | – | 37 | Deficient→Replete: 41 Insufficient→Replete: 41 |
| Insufficient | 38 | – | – | – | 37 | |||
| Replete | 35 | – | – | – | 78 | |||
| P-value | – | – | – | 0.004 | ||||
Unless otherwise noted, vitamin D status categorized as: deficient (<20 ng/mL), insufficient (20–30 ng/mL), or replete (>30 ng/mL)
CP clinical pregnany, ET embryo transfer, n sample size
aDeficient (<10 ng/mL), insufficient (10–29 ng/mL), replete (30–100 ng/mL)
bInsufficient (<75 nmol/L), sufficient (≥75 nmol/L) [75 nmol/L = 30 ng/mL]
cTertiles (Mean ± SD): Lowest: 16.74 ± 3.38; Middle: 25.58 ± 3.17; Highest: 43.01 ± 10.65
dDeficient (<20 ng/mL), not deficient (≥20 ng/mL)
e173 patients underwent oocyte retrieval but only 162 underwent ET
f“Insufficient” = 1.2 % deficient (<20 ng/mL) + 53.8 % insufficient (20–30 ng/mL)