Zinc Oxide
Zinc Oxide is a tier 3 form of Zinc, used in 2,489 on-market products and providing 80.3% elemental zinc by weight.
2,489
on-market products
tier 3
quality tier
80.3%
elemental fraction
Basis: ZnO, anhydrous (no stable hydrate)
Why this tier: Isotope-tracer RCT: absorption 49.9%, significantly lower than citrate/gluconate; 3/15 subjects showed little/no absorption.
Source: Wegmuller R et al. 2014, PMID 24259556