Vitamin D and Metabolomics

2^nd International Conference and Exhibition on Metabolomics & Systems Biology

April 08-10, 2013 Hilton Chicago/Northbrook, USA

Sunil J Wimalawansa

Accepted Abstracts: Metabolomics

Abstract :

Vitamin D is a fat-soluble secosteroid. Among the several forms of metabolites-vitamers, the two physiologically relevant forms are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol): the side chain of D2 contains a double bond between carbons 22 and 23 and a methyl group on C-24. Pre-vitamin D3 is formed in the skin and is photolyzed by ultraviolet light (UV) in a six-electron conrotatory electrocyclic reaction; it spontaneously isomerizes to vitamin D3 in an antarafacial hydride sigmatropic shift. Small quantities of vitamin D also are present in foods. Vitamin D is transported to the liver and hydroxylated into prohormone 25-hydroxycholecalciferol [25(OH)D], calcidiol. In the proximal renal tubules, it is hydroxylated (A) via parathyroid hormone (PTH)-driven, C1-hydroxylation to active vitamin D [1,25(OH) 2 D], calcitriol; and (B) via 24-hydroxylase, inactive vitamin D [24,25(OH) 2 D]. When 1, 25(OH) 2 D is synthesized by extra renal cells, including monocyte-macrophages, it acts as a paracrine-cytokine factor, defending against invading microbial pathogens. Other molecular forms of vitamin D include lumisterol (D1), 22-dihydroergocalciferol (D4), and sitocalciferol (D5). However, there are a number of intermediary metabolites whose actions are yet to be discovered. Hormone 1,25(OH) 2 D regulates blood calcium and phosphate, promoting mineralization and the growth and remodeling of bone. Thus, vitamin D insufficiency leads to poorly calcified brittle bones, whereas sufficiency prevents these, including rickets and osteomalacia. Vitamin D also modulates neuromuscular functions, damps inflammation, and modulates actions of several key genes that regulate cell proliferation, differentiation, and apoptosis. Thus, deficiency status leads to exacerbation of a variety of human disorders, including cancer and cardiovascular diseases. The metabolomics and the metabolic diagnostic tools can now be applied to diagnosis and management.

Biography :

Sunil Wimalawansa, MD, Ph.D., MBA, is a Professor of Medicine, Endocrinology, Metabolism, and Nutrition, former chief at the UMDNJ-RWJMS, Professor of Physiology and Integrative Biology, and Director, Regional Osteoporosis Center, New Jersey. He has published more than 200 scientific articles, 45 scientific book chapters, and 8 books. He has received several awards, including Clinical Excellence in Metabolic Bone Diseases; multiple young-investigator scientific awards, Glen Foundation Endocrinology/Aging awards; the Dr. Oscar Gluck Humanitarian award; and a prestigious Lifetime Achievement Award for his worldwide contributions to science, philanthropic work, and humanity. He is the founder- president of several charitable organizations worldwide.