High-dose cholecalciferol supplementation to obese infertile men is sufficient to reach adequate vitamin D status.

Obesity is associated with low vitamin D status, and the optimal supplement and dosage of cholecalciferol (vitamin D₃) or calcidiol (25OHD) for individuals with obesity have been debated. We aimed to determine the effect of high-dose vitamin D₃ supplementation on achieving adequate vitamin D levels among infertile men with normal weight v. obesity. Here, we present secondary end points from a single-centre, double-blinded, randomised clinical trial, comprising 307 infertile men randomised to active or placebo treatment for 150 days. Men in the active group initially received an oral bolus of 300 000 mg of vitamin D₃, followed by daily supplementation with 1400 mg of vitamin D₃ and 500 mg of calcium. Baseline BMI was listed as a predefined subgroup. At baseline, serum 25OHD was significantly higher in men with normal weight (BMI < 25 kg/m²) compared with men with overweight (BMI 25–30 kg/m²) and obesity (BMI > 30 kg/m²) (48 nmol/l v. 45 nmol/l and 39 nmol/l, respectively; P = 0·024). After the intervention, men with normal weight, overweight and obesity treated with vitamin D₃ had a significantly higher serum 25OHD compared with corresponding placebo-treated men (BMI < 25 kg/m²: 92 nmol/l v. 53 nmol/l, BMI = 25–30 kg/m²: 87 nmol/l v. 49 nmol/l and BMI > 30 kg/m²: 85 nmol/l v. 48 nmol/l; P < 0·001 for all, respectively). In conclusion, we show that high-dose vitamin D₃ supplementation to infertile men with obesity and low vitamin D status is sufficient to achieve adequate serum 25OHD levels. [ABSTRACT FROM AUTHOR]