Vitamin D (Vit D) is a fat-soluble vitamin that is essential in mineral and bone metabolism. Vit D status is evaluated by measuring serum 25-hydroxyvitamin D [25(OH)D]) levels. Currently, Vit D supplementation is mainly indicated in cases of vitamin deficiency. However, there are two main issues concerning Vit D supplementation. The first is related to the definition of the lower limit of normal for serum 25(OH) D. In recent years, extensive clinical research has revealed that large percentages of global […]