Vitamin D: A Mini Review on Biochemical, Clinical, Physiological and Pathophysiological Aspects
DOI:
https://doi.org/10.14738/bjhr.1303.6885Keywords:
1ά, 25(OH) 2 D3 ,24, 25-dihydroxycholecalciferol, VDR, FGF23, calcium homeostasis, immunomodulation, cancer, cardiovascular disease, precision medicine, intestinal calcium transport, vitamin D analog PRI-1906: 4E)-24a-homo-(1S)-1, 25, renal 1 ά-hydroxylase, Type 2 diabetes and vitamin D insufficiency, congestive heart failure (CHF), Ca++ and PO4 -- absorption and resorption, bone, Intestine, kidney, ectopic parathyroid adenoma, crystal structures of Vitamin D, Vitamin D receptorsAbstract
Vitamin D is a pleiotropic secosteroid hormone with critical endocrine, paracrine, and autocrine functions. Beyond its classical role in calcium and phosphate homeostasis and bone mineralization, vitamin D regulates immune responses, cardiometabolic health, cancer biology,and neurocognitive function. This narrative review integrates recent advances in vitamin D biochemistry, physiology, and pathophysiology, including the FGF23–Klotho axis, vitamin D receptor (VDR) genomics and epigenomics, extrarenal vitamin D metabolism, and precision medicine approaches. Clinical implications for deficiency, supplementation, and therapeutic analogs are discussed. Emphasis will be directed toward the structural basis for understanding the mechanism of the two-step hydroxylation that activates vitamin D3, regulation of intestinal calcium absorption, kidney calcium and phosphate resorption, the molecular mechanisms of transcellular pathway, interrelationship of vitamin D with parathyroid hormone (PTH), calcitonin and other hormones, the involvement of vitamin D in diabetes, cancer and immune disorders.
