Rising serum 25-hydroxy-vitamin D levels after weight loss in obese women correlate with improvement in insulin resistance.

Objective: The objective of the study was to examine changes of 25-hydroxy-vitamin D (25OHD) and PTH blood levels 4 and 20 wk after low-calorie diet-induced weight loss.

Methods: Forty-four obese women [aged 40.6 +/- 11.