What are the key differences between inorganic and organic selenium for supplement buyers?

What are the key differences between inorganic and organic selenium for supplement buyers?
For supplement-grade selenium, the chemical form matters more than price. Inorganic selenium—mainly sodium selenite—is cheap but poorly absorbed, with human utilization rates around 50%, and carries higher toxicity risk. Organic selenium forms, including selenomethionine, selenocysteine, and L-selenomethylselenocysteine, achieve 80% absorption and can be stored in tissues. Yeast-based selenium is a mixture, not a single compound, with selenomethionine typically comprising 97-99% of total organic selenium. Plant-derived selenium, such as malt or seaweed selenium, is essentially a commercial label for concentrated selenomethionine, not a distinct chemical entity. Consumers should check labels for the specific organic compound rather than marketing names.