Acute selenium toxicity associated with a dietary supplement.
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 microg/d (recommended dietary allowance is 55 microg/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 microg/L (reference range, < or =125 microg/L). The mean initial urine selenium concentration of 7 patients was 166 microg/24 h (reference range, < or =55 microg/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.
MacFarquhar
Jennifer K
JK
Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Broussard
Danielle L
DL
Melstrom
Paul
P
Hutchinson
Richard
R
Wolkin
Amy
A
Martin
Colleen
C
Burk
Raymond F
RF
Dunn
John R
JR
Green
Alice L
AL
Hammond
Roberta
R
Schaffner
William
W
Jones
Timothy F
TF
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000505:Alopecia / Q000139:chemically induced* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D019587:Dietary Supplements / Q000506:poisoning*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D005767:Gastrointestinal Diseases / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012643:Selenium / Q000008:administration & dosage / Q000506:poisoning*; D018036:Selenium Compounds / Q000008:administration & dosage / Q000506:poisoning*; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
D018036:Selenium Compounds; D012643:Selenium