· Zinc methionine sulfate: Certain amino acids, especially methionine, cysteine, and histidine, have a significantly enhancing effect on zinc absorption [cf. Lönnerdal B. Dietary factors influencing zinc absorption. J Nutr 2000; 130 (Suppl.): 1378S - 1383S]. These amino acids can also retain zinc in dissolved, absorbable form in the presence of phytates.
· Zinc gluconate: In a pharmacokinetic study, Neve et al. (1993) investigated serum zinc profiles in ten healthy volunteers after oral administration of six preparations of zinc sulfate and zinc gluconate, each administered at a 45 mg zinc equivalent dose [see Neve J, Hanocq M, Peretz A, Abi Khalil F, Pelen F. Etude de quelques facteurs influencant la biodisponibilité du zinc dans les formes pharmaceutiques à usage oral. J Pharm Belg 1993; 48 (1): 5 - 11]. According to the results, dividing the total zinc dose into several smaller doses could increase the overall bioavailability of zinc. Overall, the authors observed a slightly better bioavailability of zinc gluconate compared to zinc sulfate.
· Zinc picolinate: Zinc picolinate is zinc bound to picolinic acid - an organic compound that is classified as a heterocycle. Barrie et al. [cf. Barrie SA, Wright JV, Pizzorno JE, Kutter E, Barron PC. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents Actions 1987; 21 (1 - 2): 223 - 228] found in a study of 15 healthy volunteers, after 4-week double-blind administration of zinc gluconate, zinc picolinate, zinc citrate or placebo, only the picolinate resulted in a significant increase in zinc levels in the hair, urine and erythrocytes.
· Zinc bisglycinate: Zinc bisglycinate is a zinc chelate with the amino acid glycine, allowing it to penetrate the intestinal wall particularly well. Zinc bisglycinate is therefore one of the most effective forms of zinc. It appears to be well-tolerated by the body and stomach. It is well tolerated, which also makes it suitable for use by people with stomach problems. One study showed an increase of approximately... 43% increased bioavailability compared to the already easily absorbable zinc gluconate (cf. Capdor J, Foster M, Petocz P, Samman S. Zinc and glycemic control: a meta-analysis of ran-domized placebo controlled supplementation trials in humans. Journal of trace elements in medicine and biology: rgan of the Society for Minerals and Trace Elements. 2013 Apr;27(2):137-42).
· Zinc aspartate: Kruse-Jarres et al. Studies showed better absorption of zinc by zinc aspartate than by zinc chloride and zinc sulfate [cf. Kruse-Jarres JD, Herr D, Vocke G, Baur B, Baur J, Waldmann D. The absorption of zinc and magnesium by the intestinal tract. In: Henschel WF, Editor. The role of potassium magnesium aspartate in surgical medicine and intensive care: 10 years of experience with Inzolen. Stuttgart: Schattauer-Verlag, 1977: 49 - 59.].
· Zinc lysinate
· Zinc ascorbate: Zinc ascorbate is a zinc salt that combines ascorbic acid (vitamin C) and zinc. This compound is particularly easily absorbed by the body and contributes to improved immune system function.
· Zinc acetate: Zinc acetate is the zinc salt of acetic acid and is a zinc compound that is particularly well absorbed from the intestine into the bloodstream.
· Zinc malate: Organic zinc as a fruit acid chelate, in which the zinc is bound to malic acid. This is a particularly rapidly bioavailable and well-tolerated form of zinc.
Z Zinc lactate: Zinc lactate, produced by saturating lactic acid, is a soluble and therefore highly bioavailable form of zinc and contains 23.4% elemental zinc.
