Supplementation With Vitamin D Improves Leptin Resistance

Participants will be randomly assigned in one of two groups. Group A: oral supplementation with 4,000 IU of vitamin D (cholecalciferol). Group B: oral supplementation with 400 IU of vitamin D (cholecalciferol). Both treatments will be consumed daily for 6 months. Outcomes will be evaluated at baseline, three and six months. Variables related to leptin resistance will be evaluated. The main hypothesis is that vitamin D will diminish leptin resistance in overweight and obese women. If the hypothesis is confirmed, women will show a reduction in the Resting energy expenditure: serum Leptin ratio (REE: Leptin ratio), as well as a reduction of hunger, body weight, body and abdominal fat and an increase in resting energy expenditure.