A chelated mineral is a mineral bound to an organic molecule, usually an amino acid, to form a stable ring-like complex intended to improve absorption as a dietary supplement. The theory is that chelation protects the mineral through the digestive tract and uses amino acid uptake pathways, with popular forms including magnesium glycinate, zinc picolinate, and iron bisglycinate. Evidence for superior absorption over cheaper salts is mixed and varies by mineral, while chelated forms typically cost more. Consumers should check that products come from reputable manufacturers with verified content, since supplement quality varies and more absorbable is not always better.