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The role of vitamin D in hair loss
Dermatol Online J. 2010 Feb 15;16(2):3.
Does D matter? The role of vitamin D in hair disorders and hair follicle cycling.
Amor KT, Rashid RM, Mirmirani P.
Exerpt (edited for hair loss blog use)
...Another potential application for vitamin D is in hair loss due to scalp psoriasis, which is associated with an increased telogen to anagen ratio. Although vitamin D3 analogs have been used in combination or as an alternative to topical steroids to treat scalp psoriasis for many years, their ability to combat the associated alopecia has not been thoroughly evaluated. A placebo-controlled trial with 26 patients showed that calcipotriol did not affect the telogen to anagen ratio after 6 weeks of treatment [40], but the optimal effect of calcipotriol on scalp psoriasis is not seen until 8 weeks [41]. Thus, the follow up may have been too brief to detect an effect of calcipotriol on hair loss.
It has been suggested that an optimal concentration of vitamin D is necessary to delay the aging phenomena, including hair loss. A cross sectional study of 296 healthy men was done to determine the association, if any, between male pattern baldness and serum 25-hydroxyvitamin D levels [42]. Based on this study, the extent and severity of male pattern baldness does not appear to be associated with serum 25-hydroxyvitamin D levels (p=0.60) [42]. Additional studies in subjects with age-related or senescent thinning as well as in women with female pattern hair loss could be considered to see if there is an association of hair loss with serum 25-hydroxyvitamin D levels.
Because it is known that the absence of VDR leads to alopecia, it was hypothesized that there may be VDR gene polymorphisms (Bsml, Apal, and Taql) in patients with alopecia areata. A study of VDR genotypes in 32 patients with alopecia areata and 27 controls showed no association between these VDR gene polymorphisms and alopecia areata [43]. A separate study also showed that there was no relationship between the VDR gene FokI polymorphism and alopecia areata [44]. These studies were small and limited to only one ethnic group, Caucasians in Turkey.
Conclusion
Extensive data from animal models clearly show that the VDR, independent of vitamin D3 hormone, plays an important role in the hair follicle cycle, specifically anagen initiation. Studies have demonstrated the ability of vitamin D3 analogs to stimulate hair regrowth, but clinical trials of calcitriol in humans have been unable to replicate these results. Reasons for this may be that more potent analogs of vitamin D3 were used in the animal studies than the human trials. Also, the mechanism of hair recovery in nude mice may not be applicable to humans with alopecia. The latter is reflected in one study that used nude mice with congenital alopecia, which does not have an equivalent in humans. This review shows the need for further exploration of the role of vitamin D and the VDR in the hair cycle. For clinical hair disorders in which there is an abnormal hair cycle, such as chemotherapy-induced alopecia, treatments that up regulate the expression of the vitamin D receptor may be successful. Developments of such treatments are a future area of study. Furthermore, studies on the optimal levels of local and systemic vitamin D levels are still limited and there is currently no evidence-based data to recommend vitamin D supplementation for various types of alopecia. In order to fully understand the effects of vitamin D supplementation in hai rloss treatment, future studies should compare results in vitamin D deficient patients to those in vitamin D sufficient patients.
Hai rloss treatment
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