The renal excretion of selenium

Area of Science:

• Human Nutrition
• Clinical Chemistry
• Toxicology

Background:

• Selenium is an essential trace element crucial for various physiological processes.
• Understanding selenium excretion is vital for assessing human selenium status and potential toxicity.
• Urinary selenium levels are often used as a biomarker for selenium exposure.

Purpose of the Study:

• To quantify daily selenium excretion in healthy West German adults.
• To investigate correlations between urinary selenium excretion and other physiological parameters.
• To evaluate the reliability of urinary selenium as an indicator of selenium status.

Main Methods:

• Collected 24-hour urine samples from healthy West German volunteers.
• Measured urinary selenium, urea, creatinine, and potassium concentrations.
• Calculated selenium clearance from plasma and analyzed correlations between excretion parameters.

Main Results:

• Mean daily urinary selenium excretion was 17.7 µg/day for women and 19.0 µg/day for men.
• Selenium excretion positively correlated with urinary urea, creatinine, and potassium.
• Urinary selenium excretion was dependent on glomerular filtration rate and urine volume.

Conclusions:

• Selenium excretion is influenced by dietary protein intake and muscle mass.
• Kidney function, specifically glomerular filtration rate, significantly affects urinary selenium levels.
• Urinary selenium excretion alone may not be a definitive indicator of selenium status, especially in individuals with impaired kidney function.