Vitamin D Supplementation on in Major Orthopedic Surgery

"Calcifediol will be administered at a dose of 10 drops per day (as indicated for use) for 6 months or until vitamin D levels\> 30 ng / ml are obtained.~Once these values have been obtained, the dosage can be reduced to a dosage of 4/5 drops of calcifediol (1 drop contains 5mcg of calcifediol) with the aim to maintain the plasma values of 25 (OH) D in a optimal range between 30-60 ng / ml during the 6 month of the duration of the study."