TLDR Too much selenium can cause hair loss and nail problems.
The document presents a case study of a 48-year-old woman who experienced severe hair loss and nail discoloration and brittleness after taking selenium (Se) supplements and consuming selenium-rich nuts for 4 months. The woman's selenium level was found to be 1300 μg/L, significantly higher than the normal range of 23–190 μg/L. After she stopped taking the supplements and eating nuts, her symptoms improved over a period of 6 months. The study concludes that high levels of selenium, whether from supplements or diet, can lead to hair loss and nail abnormalities, a condition known as chronic selenosis. The authors recommend caution in selenium intake, especially in individuals experiencing hair loss and nail dystrophies.
30 citations,
January 2023 in “EFSA journal” Adults should not consume more than 255 micrograms of selenium per day to avoid risk of hair loss and other side effects.
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.
Fad diets and supplements from social media can cause skin and hair problems.
26 citations,
January 2018 in “Skin appendage disorders” Thallium, mercury, selenium, and colchicine strongly cause hair loss.
12 citations,
June 2023 in “Journal of trace elements in medicine and biology” Eating too much selenium can cause bad breath, hair loss, and nail changes, with harmful effects starting at low daily doses.
13 citations,
January 2012 in “International Journal of Trichology” Eating too many paradise nuts for cancer prevention caused a woman to lose all her hair due to selenium poisoning.
5 citations,
October 2013 in “Veterinary Clinics of North America: Equine Practice” Some horses lose hair without inflammation or itching due to various conditions, and while mainly a cosmetic issue, diagnosis requires examination and biopsies, and breeding is not advised if it's hereditary.
