Seasonal effects on vitamin D status influence outcomes of lifestyle intervention in overweight and obese women with polycystic ovary syndrome

Rebecca L. Thomson, Simon Spedding, Grant D. Brinkworth, Manny Noakes, Jonathan D. Buckley

Research output: Contribution to journalArticle

18 Citations (Scopus)


Objective: To investigate the effect of undertaking lifestyle interventions during periods of seasonal change on vitamin D status and health outcomes in overweight/obese women with polycystic ovary syndrome (PCOS). Design: Retrospective, unplanned secondary analysis of two cohorts during different seasons. Setting: Outpatient clinical research unit. Patient(s): Fifty overweight/obese women with PCOS. Intervention(s): Twenty-week lifestyle modification program (Clinical Trials registration no.: ACTRN12606000198527); one cohort started in winter and finished in summer, and one started in summer and finished in winter. Main Outcome Measure(s): 25-Hydroxyvitamin D (25OH-D), weight, waist circumference (WC), body composition, cardiovascular disease (CVD) risk factors, and menstrual cycle length. Result(s): Baseline 25OH-D levels were 27.6 ± 9.0 nmol/L. The winter cohort had lower 25OH-D levels at baseline, which increased over 20 weeks, whereas the summer cohort started with higher levels which decreased. Changes in 25OH-D were inversely correlated with changes in WC and cholesterol when controlling for baseline values, such that increases in 25OH-D were associated with greater reductions in WC and cholesterol. Conclusion(s): Obesity and CVD risk profiles improved in vitamin D-deficient women with PCOS after a 20-week lifestyle intervention during which vitamin D status improved with seasonal change. Clinical Trial Registration Number: ACTRN12606000198527.

Original languageEnglish
Pages (from-to)1779-1785
Number of pages7
JournalFertility and sterility
Issue number6
Publication statusPublished - 1 May 2013


  • 25-Hydroxyvitamin D
  • cholesterol
  • obesity
  • polycystic ovary syndrome
  • waist circumference

ASJC Scopus subject areas

  • Reproductive Medicine
  • Obstetrics and Gynaecology

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