Vitamin D Decreases Serum VEGF Correlating with Clinical Improvement in Vitamin D-Deficient Women with PCOS: A Randomized Placebo-Controlled Trial.

Vascular endothelial growth factor (VEGF) has been suggested to play a role in the pathophysiology of polycystic ovary syndrome (PCOS) and may contribute to increased risk of ovarian hyperstimulation syndrome (OHSS) in affected individuals. Vitamin D (VitD) supplementation improves multiple clinical parameters in VitD-deficient women with PCOS and decreases VEGF levels in several other pathologic conditions. Unveiling the basic mechanisms underlying the beneficial effects of vitamin D on PCOS may enhance our understanding of the pathophysiology of this syndrome. It may also suggest a new treatment for PCOS that can improve it through the same mechanism as vitamin D and can be given regardless of vitamin D levels. Therefore, we aimed to explore the effect of VitD supplementation on serum VEGF levels and assess whether changes in VEGF correlate with an improvement in characteristic clinical abnormalities of PCOS. This is a randomized placebo-controlled trial conducted between October 2013 and March 2015. Sixty-eight VitD-deficient women with PCOS were recruited. Women received either 50,000 IU of oral VitD3 or placebo once weekly for 8 weeks. There was a significant decrease in serum VEGF levels (1106.4 ± 36.5 to 965.3 ± 42.7 pg·mL-1; p < 0.001) in the VitD group. Previously reported findings of this trial demonstrated a significant decrease in the intermenstrual intervals, Ferriman-Gallwey hirsutism score, and triglycerides following VitD supplementation. Interestingly, ∆VEGF was positively correlated with ∆triglycerides (R² = 0.22; p = 0.02) following VitD supplementation. In conclusion, VitD replacement significantly decreases serum VEGF levels correlating with a decrease in triglycerides in women with PCOS. This is a novel molecular explanation for the beneficial effects of VitD treatment. It also suggests the need to investigate a potential role of VitD treatment in reducing the incidence or severity of OHSS in VitD-deficient women with PCOS.

Vitamin D Supplementation Decreases TGF-ß1 Bioavailability in PCOS: A Randomized Placebo-Controlled Trial.

CONTEXT: There is an abnormal increase in TGF-ß1 bioavailability in women with polycystic ovary syndrome (PCOS), which might play a role in the pathophysiology of this syndrome. Vitamin D (VD) supplementation improves various clinical manifestations of PCOS and decreases TGF-ß1 levels in several diseases including myelofibrosis. OBJECTIVE: The objective of the study was to determine the effect of VD supplementation on TGF-ß1 bioavailability in VD-deficient women with PCOS and assess whether changes in TGF-ß1/soluble endoglin (sENG) levels correlate with an improvement in PCOS clinical manifestations. DESIGN: This was a prospective, randomized, placebo-controlled trial. SETTING: The study was conducted at an academic-affiliated medical center. PARTICIPANTS: Sixty-eight VD-deficient women with PCOS who were not pregnant or taking any exogenous hormones were recruited between October 2013 and January 2015. INTERVENTIONS: Forty-five women received 50 000 IU of oral vitamin D3 and 23 women received oral placebo once weekly for 8 weeks. MAIN OUTCOMES MEASURES: Serum TGF-ß1, sENG, lipid profile, testosterone, dehydroepiandrosterone sulfate, and insulin resistance were measured. The clinical parameters were evaluated before and 2 months after treatment. RESULTS: The VD level significantly increased and normalized after VD supplementation (16.3 ± 0.9 [SEM] to 43.2 ± 2.4 ng/mL; P < .01), whereas it did not significantly change after placebo. After the VD supplementation, there was a significant decrease in the following: the interval between menstrual periods (80 ± 9 to 60 ± 6 d; P = .04), Ferriman-Gallwey score (9.8 ± 1.5 to 8.1 ± 1.5; P < .01), triglycerides (138 ± 22 to 117 ± 20 mg/dL; P = .03), and TGF-ß1 to sENG ratio (6.7 ± 0.4 to 5.9 ± 0.4; P = .04). In addition, the ΔTGF-ß1 to sENG ratio was positively correlated with Δtriglycerides (r = 0.59; P = .03). CONCLUSIONS: VD supplementation in VD-deficient women with PCOS significantly decreases the bioavailability of TGF-ß1, which correlates with an improvement in some abnormal clinical parameters associated with PCOS. This is a novel mechanism that could explain the beneficial effects of VD supplementation in women with PCOS. These findings may support new treatment modalities for PCOS, such as the development of anti-TGF-ß drugs.

Role of vitamin D in ovarian physiology and its implication in reproduction: a systematic review.

OBJECTIVE: To report an update on the role of vitamin D (VD) in ovarian physiology with a focus on genes involved in steroidogenesis, follicular development, and ovarian reserve, as well as ovulatory dysfunction associated with polycystic ovary syndrome (PCOS), and ovarian response to assisted reproductive technology (ART). DESIGN: Systematic review. SETTING: Not applicable. PATIENT(S): Human, animal, and cell culture models. INTERVENTION(S): Pubmed literature search. MAIN OUTCOME MEASURE(S): Granulosa cell function, serum antimüllerian hormone (AMH), AMH and its receptor gene expression, soluble receptor for advanced glycation end-products (sRAGE), PCOS parameters, and ART outcome. RESULT(S): In human granulosa cells, VD alters AMH signaling, FSH sensitivity, and progesterone production and release, indicating a possible physiologic role for VD in ovarian follicular development and luteinization. In the serum, 25-hydroxyvitamin D (25OH-D) is positively correlated with AMH, and appropriate VD supplementation in VD-depleted women can suppress the seasonal changes that occur in serum AMH. In VD-deficient women with PCOS, VD supplementation lowers the abnormally elevated serum AMH levels, possibly indicating a mechanism by which VD improves folliculogenesis. The antiinflammatory sRAGE serum levels significantly increase in women with PCOS after VD replacement. Although follicular fluid 25OH-D correlates with IVF outcomes, there is a lack of data pertaining to the impact of VD supplementation on pregnancy rates following IVF. CONCLUSION(S): This review underscores the need for understanding the mechanistic actions of VD in ovarian physiology and the critical need for randomized trials to elucidate the impact of VD supplementation on controlled ovarian hyperstimulation/IVF outcome and ovulatory dysfunction associated with PCOS.

Vitamin D increases serum levels of the soluble receptor for advanced glycation end products in women with PCOS.

CONTEXT: Elevation of serum proinflammatory advanced glycation end products (AGEs) is involved in the pathogenesis of polycystic ovary syndrome (PCOS). The soluble receptor for AGEs (sRAGE) acts as a decoy by binding circulating AGEs. Vitamin D supplementation attenuates the deposition of AGEs in the vascular system of diabetic animals and improves some metabolic aspects of vitamin D-deficient women with PCOS. Additionally, serum anti-Mullerian hormone (AMH) is elevated in women with PCOS, reflecting abnormal ovarian folliculogenesis. OBJECTIVE: The objective of the study was to evaluate the effect of 1,25 dihydroxyvitamin D3 (vit D3) supplementation on serum sRAGE and AMH in vitamin D-deficient women with PCOS. DESIGN, SETTINGS, PARTICIPANTS, AND INTERVENTION: Sixty-seven women with (n = 22) or without (control; n = 45) PCOS who were diagnosed with vitamin D deficiency were enrolled. Fifty-one women were replaced with oral vit D3 for 8 weeks (16 with PCOS and 35 controls) and 16 women were not treated (six with PCOS and 10 controls). Serum 25-hydroxyvitamin D (25 OH-D), sRAGE, and AMH concentrations were measured at baseline and after vit D3 supplementation in the treated group and 8 weeks apart in the nontreated group. MAIN OUTCOME MEASURE(S): Changes in serum sRAGE and AMH concentrations after vit D3 replacement were measured. RESULTS: In all participants, there was a negative correlation between body mass index and serum sRAGE levels (r = -0.3, P = .01). In women with PCOS, but not in controls, vit D3 increased serum sRAGE (P = .03) and decreased serum AMH levels (P < .001). The increase in serum sRAGE positively correlated with the increase in serum 25 OH-D after supplementation in women with PCOS (r = 0.6, P = .01). CONCLUSION: In women with PCOS, vit D3 might exert a protective effect against the inflammatory action of AGEs by increasing circulating sRAGE. The normalization in serum AMH induced by vit D3 replacement suggests an improvement in folliculogenesis.