16 citations
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February 2008 in “PubMed” Vitamin B12 deficiency can cause skin darkening and white hair, but it's reversible.
8 citations
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May 2021 in “Journal of the European Academy of Dermatology and Venereology” A COVID-19 patient had unusual nail discoloration and nail separation possibly due to the virus's effects on small blood vessels.
77 citations
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August 1986 in “Archives of Dermatology” Vitamin B12 deficiency can cause skin and hair color changes, which are reversible with treatment.
11 citations
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August 1986 in “Archives of Dermatology” Vitamin B12 deficiency can cause skin and hair color changes, which can be reversed with treatment.
4 citations
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July 2019 in “Clinics in Dermatology” The document concludes that while white skin, nail, and mucosa diseases increase skin cancer risk, they are generally harmless, especially compared to darker pigmentation conditions.