Vitamin D is a fat-soluble vitamin, which has been classically associated
with rickets and osteomalacia. The main function of Vitamin D is the regulation of
calcium and phosphorus homeostasis. Plasma levels of 25-hydroxyvitamin D or
calcidiol are considered the status indicator of Vitamin D in the human body, although
it is biologically inert. 25-hydroxyvitamin D is transformed by 1α-hydroxylase to
produce 1,25-dihydroxyvitamin D or calcitriol, the active metabolite of the vitamin.
Vitamin D performs its actions through the Vitamin D receptor (VDR) that is present in
more than 40 different tissues, as well as the enzyme 1α-hydroxylase, so it is now
thought that Vitamin D may play a role in other physiological mechanisms. In the
recent years, great interest has been a roused in Vitamin D and its involvement in
different pathologies. However, the results of the studies are unclear, due to the
involvement of mixed patients of different races, diagnostic criteria, latitude and season
blood draw and the confounding variables such as age, BMI or sex not taken into
account. The purpose of this chapter is to review the most recent publications of
Vitamin D, in relation to new applications such as: diabetes, cancer, pregnancy and
cardiovascular disease.
Keywords: 1, 25-dihydroxyvitamin D, 25-hydroxyvitamin D, Bone metabolism,
Breast cancer, Calcidiol, Calcitriol, Cardiovascular diseases, Colorectal cancer,
Deficiency, Diabetes mellitus, Gestational diabetes, Myocardial infarction, Preeclampsia,
Pregnancy, Pregnancy outcomes, Prostate cancer, VDR, VDR polymorphisms,
Vitamin D.
