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Updated: Jul 18, 2026
04:54
Assessing Mineral Availability in Fish Feeds using Complementary Methods Demonstrated with the Example of Zinc in Atlantic Salmon
Published on: October 29, 2021
[Mineral substance in human nutrition. Selenium: absorption and bioavailability]
Voprosy Pitaniia
|December 19, 2006
Summary
Selenium absorption varies by chemical form, with selenate and selenite absorbed differently in the gastrointestinal tract. Selenium bioavailability from food sources is generally high, exceeding that of many transition metals.
Area of Science:
- Nutritional biochemistry
- Gastrointestinal physiology
- Trace element metabolism
Context:
- Understanding selenium absorption is crucial for human and animal nutrition.
- Dietary selenium exists in various chemical forms, influencing its uptake and utilization.
- Previous research highlights differences in absorption rates and mechanisms for inorganic selenium species.
Purpose:
- To review and synthesize findings on selenium absorption in the gastrointestinal tract.
- To compare the absorption mechanisms of selenate, selenite, and organic selenium compounds.
- To evaluate the bioavailability of dietary selenium sources.
Summary:
- Selenate is rapidly absorbed in the ileum via a Na+ and energy-dependent process.
- Selenite absorption occurs mainly in the jejunum, is slower, and involves transport as mixed thiols.
- Selenium amino acids utilize specific amino acid transport systems; overall selenium bioavailability is high (≥60%).
Impact:
- Highlights the high bioavailability of dietary selenium, often exceeding 60%.
- Suggests evaluating selenium bioavailability based on retention and toxicity, not just absorption ratios.
- Provides insights for optimizing selenium intake and understanding its nutritional significance.
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