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Two paper about Selenium Toxicity

11 February, 2010
  • Acute selenium poisoning by paradise nuts (Lecythis ollaria).Müller D, Desel H.See. Two previously healthy women developed nausea, vomiting, headache and dizziness for several days, a massive hair loss about 2 weeks later and a discoloration of the fingernails. Detailed diagnostic procedures did not reveal any pathological results. Therapeutic measures did not show any effect. Thallium and arsenic were within normal range in plasma. Delayed quantitative determination of selenium in blood, however revealed toxic values (in case I: 479 mug/L of serum, 8 weeks after ingestion, and in case II 300 mug/L of serum, 9 weeks after ingestion). In retrospect, a relation to the ingestion of paradise nuts could be.
  • Acute Selenium Toxicity Associated With a Dietary Supplement. Jennifer K. MacFarquhar, Danielle L. Broussard, Paul Melstrom, et al. Arch Intern Med. 2010;170(3):256-261. See abstract or read then. Sent by Alfredo Rovere

Background  Selenium is an element necessary for normal cellular function, but it can have toxic effects at high doses. We investigated an outbreak of acute selenium poisoning.
Methods  A case was defined as the onset of symptoms of selenium toxicity in a person within 2 weeks after ingesting a dietary supplement manufactured by "Company A," purchased after January 1, 2008. We conducted case finding, administered initial and 90-day follow-up questionnaires to affected persons, and obtained laboratory data where available.
Results  The source of the outbreak was identified as a liquid dietary supplement that contained 200 times the labeled concentration of selenium. Of 201 cases identified in 10 states, 1 person was hospitalized. The median estimated dose of selenium consumed was 41 749 µg/d (recommended dietary allowance is 55 µg/d). Frequently reported symptoms included diarrhea (78%), fatigue (75%), hair loss (72%), joint pain (70%), nail discoloration or brittleness (61%), and nausea (58%). Symptoms persisting 90 days or longer included fingernail discoloration and loss (52%), fatigue (35%), and hair loss (29%). The mean initial serum selenium concentration of 8 patients was 751 µg/L (reference range, 125 µg/L). The mean initial urine selenium concentration of 7 patients was 166 µg/24 h (reference range, 55 µg/24 h).
Conclusions  Toxic concentrations of selenium in a liquid dietary supplement resulted in a widespread outbreak. Had the manufacturers been held to standards used in the pharmaceutical industry, it may have been prevented.

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