TLDR Taking too many vitamin and mineral supplements can cause serious health problems.
The 2010 document outlines the potential adverse effects of oral vitamin (A, D, E, niacin) and mineral (zinc, copper, iron) supplements in dermatology, cautioning against excessive intake beyond the RDA due to severe side effects. It notes hematologic and neurologic issues from zinc, liver damage from copper, and gastrointestinal issues and increased risk of hypertension and diabetes from iron. Vitamin A can cause hypervitaminosis A, niacin can lead to flushing and liver toxicity, vitamin D excess can result in hypercalcemia, and vitamin E, while beneficial for skin health, can cause allergic reactions and has been linked to increased mortality at high doses. A study with 96 patients showed oral vitamin E improved atopic dermatitis symptoms, but a meta-analysis of 19 trials with over 135,000 participants associated high-dose vitamin E with increased all-cause mortality. Dermatologists should prescribe supplements with caution, considering drug interactions, therapeutic and toxic levels, and potential side effects.
207 citations,
April 2006 in “Journal of The American Academy of Dermatology” Iron deficiency may be related to hair loss, but there's not enough evidence to recommend iron screening or supplements for all hair loss patients.
32 citations,
January 2006 in “Liver transplantation” Vitamin A toxicity can cause severe health issues and may require a liver transplant if other treatments fail.
163 citations,
November 2003 in “Journal of Investigative Dermatology” Low iron levels may be linked to some types of hair loss in women.
79 citations,
January 2017 in “Dermatology practical & conceptual” Correcting nutrient deficiencies may help with hair loss, but the benefits of supplements without a deficiency are uncertain and could be harmful.
January 2012 in “Vitamins & trace elements” Smoking and drinking can lower vitamin levels and potentially trigger early hair loss, but overall vitamin levels don't seem to affect hair loss duration.
63 citations,
May 2017 in “American Journal of Clinical Dermatology” People with alopecia areata often have lower levels of vitamin D, zinc, and folate, but more research is needed to understand if supplements can help treat it.
134 citations,
December 2018 in “Dermatology and Therapy” Some vitamins and minerals like vitamin D and iron can help with certain types of hair loss, but more research is needed for others.
January 2017 in “Springer eBooks” Eating a balanced diet with specific nutrients can help manage menopause symptoms and prevent related health issues.