[Vitamin D : More than just a bone hormone]

Area of Science:

• Endocrinology and Metabolism
• Bone Biology
• Immunology

Background:

• Vitamin D is essential for calcium and phosphate regulation, vital for bone mineral density and osteoporosis management.
• The widespread Vitamin D Receptor (VDR) distribution suggests diverse physiological roles beyond skeletal health.
• Vitamin D deficiency is prevalent and linked to various non-skeletal health issues in observational studies.

Purpose of the Study:

• To summarize current knowledge on the extraskeletal effects of Vitamin D.
• To review Vitamin D's impact on muscle function, glucose metabolism in type 2 diabetes mellitus, and cardiovascular risk.
• To discuss Vitamin D's influence on the immune system, including infectious and autoimmune diseases.

Main Methods:

• Review of existing literature and ongoing randomized controlled trials.
• Synthesis of evidence from experimental and observational studies.
• Discussion of Vitamin D's pleiotropic effects mediated by the VDR.

Main Results:

• Vitamin D influences muscle, glucose metabolism, cardiovascular health, and immune responses.
• Evidence suggests potential benefits for infectious diseases and autoimmune conditions like type 1 diabetes mellitus.
• Ongoing trials are investigating high-dose Vitamin D supplementation for chronic diseases.

Conclusions:

• Vitamin D deficiency should be avoided in patients with various chronic diseases.
• Further research and clinical trials are necessary to fully elucidate Vitamin D's extraskeletal benefits.
• Optimal Vitamin D dosage recommendations are under discussion for various health conditions.