Although there is no current consensus, vitamin D insufficiency is usually defined as 25OHD levels lower than 30 ng/ml (or 75 nmol/l) [5], because this limit is associated with a decrease in active intestinal calcium absorption [6] and with an increase in secretion of serum parathormone (PTH), which is involved in maintenance of normal serum calcium levels [5]. Here, PTH is linked to vitamin D deficiency.