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Vitamin D: Actions for the new millennium
H Lai1, R Pandey, S K Aggarwal
1Department of Biochemistry, Pt. B.D. Sharma Post Graduate Institute of Medical Sciences, 15/8 FM, Medical Enclave, 124 001 Rohtak, Haryana.
Indian Journal of Clinical Biochemistry : IJCB
|October 30, 2012
Summary
Recent research reveals novel aspects of vitamin D metabolism, including plant-based sources and extrarenal synthesis of active vitamin D (calcitriol). This active form impacts multiple bodily systems beyond bone health, suggesting therapeutic potential.
Area of Science:
- Endocrinology
- Molecular Biology
- Nutritional Science
Background:
- Vitamin D metabolism has evolved with discoveries of free vitamin D(3) in plants and extrarenal synthesis of active vitamin D (calcitriol).
- The vitamin D receptor (VDR) mediates genomic effects, while VDR-independent pathways also exist.
- Calcitriol's functions extend beyond calcium and bone homeostasis, influencing various physiological systems.
Purpose of the Study:
- To explore the recent advancements in vitamin D metabolism and its broader biological implications.
- To highlight the dual genomic and non-genomic mechanisms of calcitriol action.
- To underscore the potential therapeutic applications of calcitriol and its analogues.
Main Methods:
- Review of recent scientific literature on vitamin D metabolism and action.
- Analysis of cellular mechanisms, including VDR-dependent and VDR-independent pathways.
- Characterization of calcitriol's effects on various organ systems.
Main Results:
- Free vitamin D(3) is found in plants, and active vitamin D (calcitriol) is synthesized outside the kidneys.
- Calcitriol exerts effects through both genomic (VDR-mediated) and non-genomic pathways.
- Calcitriol influences perinatal growth, immune function, and endocrine, cardiovascular, reproductive, and nervous systems.
Conclusions:
- Vitamin D metabolism is more complex than previously understood, with significant extrarenal and non-skeletal roles.
- Calcitriol's diverse biological effects suggest its potential in treating conditions like osteoporosis, neoplasia, and insulin resistance.
- Further research into calcitriol and its analogues could lead to novel therapeutic strategies.
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