» Vitamin D3 analogs stimulate hair growth in nude mice.
» Vegesna V, O’Kelly J, Uskokovic M, Said J, Lemp N, Saitoh T, Ikezoe T,
» Binderup L, Koeffler HP.
» Cedars-Sinai Medical Center/University of California Los Angeles School of
» Medicine, Los Angeles, California 90048, USA.
» The active form of vitamin D3 can regulate epidermal keratinization by
» inducing terminal differentiation; and mice lacking the vitamin D receptor
» display defects leading to postnatal alopecia. These observations implicate
» the vitamin D3 pathway in regulation of hair growth. We tested the ability
» of 1,25 dihydroxyvitamin D3 and its synthetic analogs to stimulate hair
» growth in biege/nude/xid (BNX) nu/nu (nude) mice exhibiting congenital
» alopecia. Nude mice were treated with different vitamin D3 analogs at doses
» that we had previously found to be the highest dose without inducing
» toxicity (hypercalcemia). The mice were monitored for hair growth and were
» scored according to a defined scale. Skin samples were taken for
» histological observation of hair follicles and for extraction of RNA and
» protein. Vitamin D3 analogs dramatically stimulated the hair growth of nude
» mice, although parental 1,25 dihydroxyvitamin D3 had no effect. Hair growth
» occurred in a cyclical pattern, accompanied by formation of normal hair
» follicles and increased expression of certain keratins (Ha7, Ha8, and Hb3).
» Vitamin D3 analogs seem to act on keratinocytes to initiate hair follicle
» cycling and stimulate hair growth in mice that otherwise do not grow hair.
Since our bodies make Vitamin D from sunlight, it’s possible that our bodies might have evolved a mechanism to thin our hair in response to low levels of Vitamin D, to allow more sunlight to reach the scalp, thereby allowing the body to create more Vitamin D from the additional sunlight.
So it might not be so much that more D increases hair growth, as that less D decreases hair growth.
This would fit the fact that our hair grows faster in summer than in winter–because in winter we get less sunlight (especially true for those of us whose ancestors evolved north or south of the equator).
I always figuted the need to produce D from sunlight is why northern races tend to have light hair, while the need to protect the skin from cancer is why southern races tend to have dark hair (same with skin color: northern races fair skin, southern races dark skin).
If this is true, then taking or allowing the body to make more Vitamin D would not cure or counteract male pattern baldness. But doing so would restore any thinning that might result from Vitamin D deficiency.
Currently there is growing debate concerning how much D our bodies need, and evidence is growing that people living in industrial societies are mostly D deficient, even when the D in their bodies equals current recommended levels.
The growing view is that what has been considered an adequate level of D is way too low.