Extraskeletal actions of vitamin D

Area of Science:

• Endocrinology
• Molecular Biology
• Cell Biology

Background:

• The vitamin D receptor (VDR) and the enzyme CYP27B1, which produces vitamin D's active metabolite, are widely expressed in various body cells.
• This broad expression suggests vitamin D's functions extend beyond skeletal homeostasis.

Purpose of the Study:

• To review the extraskeletal actions of vitamin D signaling in various tissues.
• To assess the translation of preclinical findings into effective human disease treatments.

Main Methods:

• Review of cell culture studies.
• Analysis of in vivo animal studies.
• Examination of clinical association studies and randomized, placebo-controlled trials.

Main Results:

• Extensive evidence from in vitro and in vivo studies confirms substantial extraskeletal effects of vitamin D.
• Randomized clinical trials have generally not validated the anticipated therapeutic benefits.

Conclusions:

• Vitamin D signaling plays a significant role in numerous extraskeletal tissues.
• Translating observed extraskeletal effects into successful clinical treatments remains a challenge.