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Published on: September 25, 2017
Nickel absorption and kinetics in human volunteers
F W Sunderman1, S M Hopfer, K R Sweeney
1Department of Laboratory Medicine, University of Connecticut School of Medicine, Farmington 06032.
Summary
Dietary factors significantly impact nickel absorption. Ingesting nickel sulfate in water led to 27% absorption, while in food, only 0.7% was absorbed, highlighting reduced bioavailability from food.
Area of Science:
- Environmental Health
- Toxicology
- Human Physiology
Background:
- Nickel (Ni) is a common environmental and dietary element.
- Understanding nickel bioavailability is crucial for human health risk assessment.
- Previous studies have indicated variability in nickel absorption based on its form and matrix.
Purpose of the Study:
- To mathematically model the kinetics of nickel absorption, distribution, and elimination in humans.
- To compare nickel bioavailability when ingested via drinking water versus food.
- To inform toxicological risk assessments for human nickel exposure.
Main Methods:
- Mathematical modeling using a compartmental model.
- Administering nickel sulfate (NiSO4) doses to healthy volunteers via drinking water (Experiment 1) and food (Experiment 2).
- Analyzing nickel concentrations in serum, urine, and feces using electrothermal atomic absorption spectrophotometry.
Main Results:
- Nickel absorption averaged 27% from water versus 0.7% from food, a 40-fold difference.
- Elimination half-time for absorbed nickel was approximately 28 hours.
- Renal clearance of nickel was higher when ingested in water compared to food.
Conclusions:
- Dietary components significantly reduce nickel (Ni2+) bioavailability for intestinal absorption.
- Approximately 25% of nickel from drinking water is absorbed, compared to only 1% from food.
- The developed kinetic model and parameters enhance the accuracy of human nickel exposure risk assessments.
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