Selenium Amino Acid Chelate vs. Sodium Selenite
Among 4,693 on-market selenium products with an identifiable primary form, 17.3% use Selenium Amino Acid Chelate (811 products) and 11.3% use Sodium Selenite (528).
| Selenium Amino Acid Chelate | Sodium Selenite | |
|---|---|---|
| Quality tier | Unrated | Tier 2 |
| Selenium by weight | — | 45.7% |
| Share of market | 17.3% | 11.3% |
| On-market products | 811 | 528 |
| Median declared dose | 50 elemental mcg middle half: 20–100 | 50 elemental mcg middle half: 19.25–70 |
| Most common brands | Airborne, Ultima, Douglas Laboratories | Wonder Laboratories, DC, SmartyPants |
Doses are declared per serving in elemental mcg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).
Why Selenium Amino Acid Chelate is unrated
Terminology inconsistent across manufacturers; composition cannot be determined from the name alone.
Source: none (definitional caveat; no source defines the composition of "selenium amino acid chelate")
Why Sodium Selenite is tier 2
Well absorbed but less well retained than organic selenomethionine (organic forms show higher retention than inorganic forms; Fairweather-Tait 2010).
Source: Fairweather-Tait SJ, Collings R, Hurst R. 2010, Am J Clin Nutr 91(5):1484S-1491S, PMID 20200264