Background: Polycystic ovary syndrome (PCOS) is as common as 5-10% of all women in Austria.
PCOS women frequently present with metabolic disturbances, hyperandrogenism and infertility.
New therapy concepts are warranted. In our recent pilot study, vitamin D (vitD)
supplementation significantly improved glucose metabolism and fertility. However, the
efficacy of vitD administration shows individual variability indicating endogenous influences
on pharmacological effects.
A recent genome-wide association study reported three loci (DHCR7, CYP2R1, and GC) associated
with vitD insufficiency. Moreover, vitD receptor (VDR) gene variants have already been known
to be associated with insulin resistance.
Aim: To test the hypothesis that vitD is efficient in changing metabolic parameters in PCOS
and non-PCOS women longitudinally and to generate data on pharmacogenetic effects of vitD
related genetic determinants adjusted for environmental factors.
Primary outcome: Change from baseline in AUCgluc after vitD treatment. Secondary outcome: To
generate the hypothesis that changes in metabolic and endocrine parameters following vitD
treatment are associated with vitD related gene variants.
Methods: 150 PCOS women with 25-hydroxyvitamin D (cholecalciferol, [25(OH)D]) levels <30
ng/ml will be treated with vitD (20,000 IU/wk) or placebo in a 2:1 randomized controlled
trial over 24 weeks and investigated for metabolic and endocrine parameters as well as vitD
related genetic variants. In addition, 150 non-PCOS women with 25(OH)D <30 ng/ml will be
treated with vitD (20,000 IU/wk) or placebo in a 2:1 randomized controlled trial over 24
weeks and investigated for metabolic and endocrine parameters as well as vitD related genetic
variants. The response to vitD supplementation in both groups will be analysed according to
Significance: VitD might be a new therapeutic option without major side effects for PCOS
patients. Exploring specific loci for pharmacogenetic vitD actions would open a new window
for therapy modulation in PCOS and other metabolic diseases.