18 citations
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October 2014 in “Experimental Biology and Medicine” This study found that feeding mice high levels of dietary vitamin A increased WNT signaling, which activated hair follicle stem cells and may have accelerated alopecia areata progression.
6 citations
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February 2021 in “Frontiers in Cell and Developmental Biology” This study suggests that vitamin A may inhibit hair follicle stem cells during refractory telogen in a dose-dependent manner, based on retinyl ester levels and vitamin A metabolism protein localization in mice.
April 2017 in “The FASEB Journal” This study suggests that excess dietary vitamin A may arrest hair follicles in refractory telogen in mice, while adequate levels promote competent telogen, revealing dose-dependent effects on hair cycling.
July 2025 in “Food Science & Nutrition” This study found that vitamin D supplementation in diets of Rex rabbits improved hair follicle development and fatty acid metabolism, with 1400–2100 IU/kg proving most effective for hair density and 2800 IU/kg increasing hair length.
January 2015 in “OhioLink ETD Center (Ohio Library and Information Network)” This animal study found that high dietary vitamin A levels altered hair cycling by affecting WNT and BMP signaling pathways in mice, which could be reversed by reducing vitamin A intake.