Until recently, vitamin D repletion was defined as the minimal concentration that enables the prevention of rickets in children and osteomalacia in adults, i.e, approximately 8 ng/mL (20 nmol/L). However, most of the international experts agree to set minimal threshold of 25 OH vitamin D serum concentration, higher than the one previously admitted, with a limit of 20 ng/mL (50 nmol/L) to define a vitamin D deficiency and a limit of 30 ng/mL (75 nmol/L) to define vitamin D insufficiency.