Zinc Picolinate

Zinc picolinate is zinc chelated to picolinic acid, a tryptophan metabolite used here as the carrier ligand. One double-blind, four-period crossover trial in 15 healthy adults found that hair, urine, and erythrocyte zinc rose significantly on zinc picolinate at 50mg elemental zinc per day, while zinc citrate, zinc gluconate, and placebo produced no significant change in those three markers (Barrie 1987, PMID: 3630857). That trial reported significance levels only. It did not report a fold-difference in absorption between the forms, so no absorption multiple can be attributed to it. Barrie 1987 has not been replicated, and it is the only trial cited on this page that tested picolinate directly, so the bioavailability advantage is best read as suggestive rather than settled. The remaining findings below tested zinc in other forms and speak to zinc as a mineral, not to the picolinate form specifically.