L-Selenomethionine vs. Sodium Selenate
Among 4,693 on-market selenium products with an identifiable primary form, 57.5% use L-Selenomethionine (2,697 products) and 14% use Sodium Selenate (657).
| L-Selenomethionine | Sodium Selenate | |
|---|---|---|
| Quality tier | Tier 1 | Tier 2 |
| Selenium by weight | 40.3% | 21.4% |
| Share of market | 57.5% | 14% |
| On-market products | 2,697 | 657 |
| Median declared dose | 70 elemental mcg middle half: 35–105 | 55 elemental mcg middle half: 20–100 |
| Most common brands | Pure Encapsulations, GNC Mega Men, Carlson | 21st Century, Vitamin World, Nature's Way |
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 L-Selenomethionine is tier 1
More complete absorption and greater tissue retention than selenite in comparative reviews; the form used in the two largest human RCTs (NPC, SELECT).
Source: Clark LC et al. 1996, JAMA 276(24):1957-1963; Lippman SM et al. 2009, JAMA 301(1):39-51
Why Sodium Selenate is tier 2
Inorganic selenate is well absorbed but, like selenite, less well retained in tissue than organic selenomethionine per general bioavailability literature.
Source: uncertain -- needs review for a direct comparative citation