Review Article

Vitamin D Supplementation Ameliorates Metabolic Dysfunction in Patients with PCOS: A SystematicReview of RCTs and Insight into the Underlying Mechanism

Table 1

Summary of RCTs focusing on the effect of Vitamin D supplementation in women with polycystic ovary syndrome.

Author/year/countryPopulation/age/vitamin D levelInterventionDuration25OHD before treatment(g/ml)25OHD after treatment (ng/ml)HyperandrogenismInsulin resistanceDyslipidemiaInflammation

Seyyed et al., (2017)
Iran [19]
36 women with PCOS,
aged 20–38 years,
25OHD < 20 ng/ml
G1: 50,000 IU/week of oral vitamin D3 (n = 19);
G2: placebo (n = 17)
8 weeksG1: 3.5 ± 4.2;
G2: 9.8 ± 5.1
28.24 ± 6.47;
13.3 ± 7.1
↓FPG ↔HOMA-IR,
QUICKI

Asemi et al., (2017)
Iran [21]
104 overweight and obese women with PCOS,
aged 18–40 years,
25OHD < 20 ng/ml
G1: 1000 mg/d calcium + vitamin D placebo (n = 26);
G2: 50,000 IU/week vitamin D + calcium placebo (n = 26);
G3: 1000 mg/d calcium+ 50,000 IU/week vitamin D (n = 26);
G4: calcium placebo + vitamin D placebo (n = 26)
8 weeksG1: 13.9 ± 2.0;
G2: 11.6 ± 4.7;
G3: 15.1 ± 3.6;
G4: 14.0 ± 4.1
71.2 ± 14.7;
86.8 ± 16.1;
76.4 ± 13.3;
73.5 ± 23.8
↓insulin, HOMA-IR,
↑QUICKI
↔FPG
↓TG, VLDL-C
↔TC, LDL-C, HDL-C
8 weeks

Bonakdaran et al., (2012)
Iran [26]
48 women with PCOS,
aged 20–40 years,
25OHD < 20 ng/ml
G1: 1000 mg/d metformin (n = 17);
G2: 0.5ug/d calcitriol (n = 15);
G3: placebo (n = 16)
12 weeksG1:28.2 ± 13.5;
G2:11.4 ± 8.2;
G3:19.9 ± 16.5;
26.7 ± 10.6;
20.1 ± 16.2;
19.0 ± 15.3
↔Total testosterone,
DHEAS
↔FPG, insulin,
HOMA-IR

Foroozanfard et al., (2015)
Iran [22]
104 overweight women with PCOS who have vitamin D deficiency,
aged 18–40 years,
25OHD < 20 ng/ml
G1: 1000 mg calcium/d plus vitamin D placebo weekly (n = 26);
G2: 50,000 IU/week vitamin D plus calcium placebo daily (n = 26);
G3: 1000 mg/d calcium plus 50,000 IU vitamin D weekly (n = 26);
G4: calcium placebo daily plus vitamin D placebo weekly (n = 26)
8 weeksG1: +0.3 ± 0.4;
G2: +12.5 ± 1.1;
G3: +9.2 ± 1.5;
G4: +0.2 ± 0.6
↓hs-CRP

Gupta et al., (2017)
India [27]
50 women with PCOS,
aged 18–45 years,
25OHD < 30 ng/ml
G1: 12000 IU/week vitamin D (n = 25);
G2: placebo (n = 25)
12 weeksG1: 18.56 ± 9.68;
G2: Vacant
44.90 ± 9.04;
vacant
↔-Total testosterone,
DHEAS
↓FPG,
insulin, HOMA-IR
↑ QUICKI
↔TG, TC,
HDL-C

Rahimi-Ardabili et al., (2013)
Iran [25]
50 women with PCOS,
aged 20–40 years,
25OHD < 20 ng/ml
G1: 50,000 IU/20 days of oral cholecalciferol (n = 24);
G2: placebo (n = 26)
8 weeksG1:6.9 ± 2.8;
G2:7.28 ± 2.93
23.4 ± 6.14;
8.57 ± 3.98
↓ TC
↔TG, LDL-C, HDL-C,
VLDL-C
↓hs-CRP
Javed et al. (2019)
UK [30]
37 women with PCOS,
aged 18–45 years,
25OHD < 20 ng/ml
G1: 3200IU/day vitamin D (n = 18);
G2: placebo (n = 19)
12 weeksG1:10.26 ± 4.57;
G2:12.38 ± 4.45
36.22 ± 7.81;
19.07 ± 8.21
↔Total testosterone,
SHBG
↔FPG, insulin,
HOMA-IR
↔TG, TC, LDL-C,
HDL-C
↔ hs-CRP

Irani et al., (2015)
USA [31]
53 women with PCOS,
aged 18–38 years,
25OHD <20 ng/ml
G1: 50,000 IU/week of oral vitamin D3 (n = 35);
G2: placebo (n = 18)
8 weeksG1: 16.3 ± 0.9;
G2: 17 ± 1.8
43.2 ± 2.4;
17.4 ± 1.9
↔Total testosterone,
SHBG
↔ HOMA-IR↓TG
↔HDL-C,
LDL-C

Maktabi et al., (2017)
Iran [24]
60 women with PCOS,
aged 18–40 years,
25OHD < 20 ng/ml
G1: 50,000 IU/2 weeks of oral vitamin D3 (n = 30);
G2: placebo (n = 30)
12 weeksG1: 12.8 ± 4.5;
G2: 14.5 ± 5.1
27.5 ± 9.8;
14.4 ± 5.2
↔Total testosterone,
SHBG, DHEAS
↓FPG, insulin,
HOMA-IR, QUICKI
↔TG, TC, LDL-C,
HDL-C, VLDL-C
↓hs-CRP

Jorly Mejia-Montilla et al., (2018)
Venezuela [29]
169 women with PCOS,
aged 20–40 years,
25OHD < 20 ng/ml
G1: 5000 IU/day vitamin D (n = 84);
G2: placebo (n = 85)
12 weeksG1:13.7 ± 4.2;
G2:13.5 ± 4.4
19.1 ± 4.9;
13.3 ± 4.5
↓FPG, insulin,
HOMA-IR
↓TG, TC, LDL-C
↔HDL-C

Ardabili et al., (2012)
Iran [20]
50 women with PCOS,
aged 20–40 years,
25OHD < 20 ng/ml
G1:50,000 IU of oral vitamin D3 every 20 days (n = 24);
G2: placebo (n = 26)
8 weeksG1: 6.9 ± 2.8;
G2: vacant
23.4 ± 6.1;
vacant
↔FPG, insulin,
HOMA-IR,
QUICKI

Jafari-Sfidvajani et al., (2017)
Iran [23]
56 women with PCOS,
aged 20–40 years,
25OHD < 20 ng/ml
G1: low-calorie diet+ 50,000 IU/week oral vitamin D3 (n = 26);
G2: low-calorie diet + placebo (n = 28)
12 weeksG1: 15.83 ± 4.85;
G2: 14.93 ± 5.55
43.38 ± 12.61;
25.32 ± 10.13
↔Total testosterone,
DHEAS, SHBG

Trummer et al., (2018)
Austria [28]
123 women with PCOS,
aged ≥ 18 years,
25OHD < 30 ng/ml
G1:20,000 IU of oral vitamin D3/week (n = 81);
G2: placebo (n = 42)
24 weeksG1: 19.55 ± 6.73;
G2: 19.55 ± 7.01
36.14 ± 8.05;
22.76 ± 11.82
↔Total testosterone↔ FPG, HOMA-IR,
QUICKI
↔TG, TC

IU: international units; FPG: fasting plasma glucose; IR: insulin resistance; HOMA-IR: homeostasis model of assessment-estimated insulin resistance; QUICKI: quantitative insulin sensitivity check index; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; VLDL-C: very low-density lipoprotein cholesterol; TC: total cholesterol; TG: triglyceride; hs-CRP: high sensitive C-reactive protein; SHBG: sex hormone-binding globulin; DHEAS: dehydroepiandrosterone sulfate.