Does D matter? The role of vitamin D in hair disorders and hair follicle cycling.
BACKGROUND
The role of vitamin D in the proliferation and differentiation of keratinocytes is well known within the field of dermatology.


OBJECTIVE
We sought to evaluate the role that vitamin D and the vitamin D receptor play in the hair cycle and assess how this can be clinically applied to the treatment of hair disorders.


METHODS
A MEDLINE search (1955-July 2009) was preformed to find relevant articles pertaining to vitamin D, the vitamin D receptor, and hair loss.


RESULTS
The vitamin D receptor, independent of vitamin D, plays an important role in hair cycling, specifically anagen initiation. The role of vitamin D in hair follicle cycling is not as well understood.


CONCLUSIONS
The review is broad and there are limited human studies available to date.


CONCLUSIONS
Additional studies to evaluate the role of vitamin D in the hair cycle should be done. Treatments that up regulate the vitamin D receptor may be successful in treating hair disorders and are a potential area of further study.
Amor
Karrie T
KT
Department of Dermatology, University of Texas and MD Anderson Cancer Center, Houston, Texas, USA. rashidrashid.mdphd@yahoo.com
Rashid
Rashid M
RM
Mirmirani
Paradi
P
D000505:Alopecia / Q000235:genetics; D000818:Animals; D006197:Hair / Q000187:drug effects / Q000196:embryology / Q000254:growth & development; D006201:Hair Diseases / Q000188:drug therapy*; D018859:Hair Follicle / Q000502:physiology*; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism*; D047488:Retinoid X Receptors / Q000235:genetics; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics; D014807:Vitamin D / Q000378:metabolism* / Q000494:pharmacology / Q000627:therapeutic use*; D051153:Wnt Proteins / Q000378:metabolism
C490267:HR protein, human; D018167:Receptors, Calcitriol; D047488:Retinoid X Receptors; D014157:Transcription Factors; D051153:Wnt Proteins; D014807:Vitamin D