Table 5.
Summary of meta-analyses of randomized controlled trials on vitamin D supplementation for pregnant women with gestational diabetes mellitus and its impact on maternal and offspring health.
| Outcomes | First author | Year | No. of articles in MA | Comparator (vitamin D supplementation or level) | Effects model | Metric of MA | Effect size | 95% CI | I2 (%) | Publication bias |
|---|---|---|---|---|---|---|---|---|---|---|
| Pregnant health | ||||||||||
| Preterm birth | Wu | 2023 | 10 | high dose (≥ 400 IU/day) vs placebo | fixed-effect | OR | 0.37 | (0.22 ~ 0.62)* | 0 | NA |
| Total cholesterol | Wu | 2023 | 7 | high dose (≥ 400 IU/day) vs placebo | random-effect | SMD | (-0.67) | (-1.19 ~ -0.14)* | 85 | NA |
| Low-density lipoprotein cholesterol | Wu | 2023 | 7 | high dose (≥ 400 IU/day) vs placebo | fixed-effect | SMD | (-0.49) | (-0.68 ~ -0.29)* | 30 | NA |
| Triglycerides | Wu | 2023 | 6 | high dose (≥ 400 IU/day) vs placebo | random-effect | SMD | (-0.59) | (-1.01 ~ -0.17)* | 77 | NA |
| High-density lipoprotein cholesterol | Wu | 2023 | 8 | high dose (≥ 400 IU/day) vs placebo | fixed-effect | SMD | 0.41 | (0.23 ~ 0.58)* | 0 | NA |
| 25(OH)D | Wu | 2023 | 9 | high dose (≥ 400 IU/day) vs placebo | random-effect | SMD | 4.07 | (2.73 ~ 5.41)* | 97 | NA |
| HOMA-IR | Wang | 2021 | 8 | supplementation vs placebo or nothing | random-effect | MD | (-1.06 mmol/L) | (-1.40 ~ -0.72)* | 74 | NA |
| Cesarean section | Wang | 2021 | 9 | supplementation vs placebo or nothing | random-effect | RR | 0.75 | (0.63 ~ 0.89)* | 43 | NA |
| Hospitalization | Wang | 2021 | 2 | supplementation vs placebo or nothing | fixed-effect | RR | 0.13 | (0.02 ~ 0.98)* | 0 | NA |
| Postpartum hemorrhage | Wang | 2021 | 2 | supplementation vs placebo or nothing | fixed-effect | RR | 0.47 | (0.22 ~ 1.00) | 0 | NA |
| Fasting plasma glucose | Wang | 2021 | 11 | supplementation vs placebo or nothing | random-effect | MD | (-10.2 mg/dL) | (-13.43 ~ -6.96)* | 80 | NA |
| Fasting insulin level | Wang | 2021 | 8 | supplementation vs placebo or nothing | random-effect | MD | (-5.02 μIU/mL) | (-6.83 ~ -3.20)* | 78 | NA |
| Infant health | ||||||||||
| Hyperbilirubinemia | Wu | 2023 | 9 | high dose (≥ 400 IU/day) vs placebo | fixed-effect | OR | 0.38 | (0.25 ~ 0.58)* | 0 | NA |
| Hospitalization | Wu | 2023 | 4 | high dose (≥ 400 IU/day) vs placebo | fixed-effect | OR | 0.29 | (0.16 ~ 0.53)* | 0 | NA |
| Giant children | Wang | 2021 | 6 | supplementation vs placebo or nothing | fixed-effect | RR | 0.58 | (0.38 ~ 0.89)* | 0 | NA |
| Fetal distress | Wang | 2021 | 2 | supplementation vs placebo or nothing | fixed-effect | RR | 0.46 | (0.24 ~ 0.90)* | 0 | NA |
| Polyhydramnios | Wang | 2021 | 4 | supplementation vs placebo or nothing | fixed-effect | RR | 0.42 | (0.24 ~ 0.72)* | 0 | NA |
| Hypoglycemia | Wang | 2021 | 4 | supplementation vs placebo or nothing | fixed-effect | RR | 0.82 | (0.52 ~ 1.29) | 0 | NA |
MA meta-analysis, OR odds ratio, RR relative risk, MD mean difference, SMD standardized mean difference, NA not available; *significant difference; 25(OH)D 25-hydroxyvitamin D, HOMA-IR homeostasis model assessment of insulin resistance.