Zinc has been gathering attention in recent years thanks to overall increased awareness in health and well-being. Today zinc has taken over the spotlight as a key ingredient in health-focused formulations as it supports normal function of the immune system. Immune system support has been a focus during the 2020 COVID-19 global pandemic.
The importance of zinc in our body is widely known thanks to its numerous health benefits, such as supporting protein and DNA synthesis, enzyme function, bone structure, nerve function and cognitive function. Zinc is an essential mineral, which is a component of approximately 300 enzymes and 2000 transcriptional factors. About 10% of the human proteome contain zinc-binding motives.
Good dietary sources of zinc are primarily foods from animal origin like meat, liver, fish, milk and cheese. Zinc plant sources, like legumes and whole grains, are often less bioavailable because of potential intestinal absorption impairment by anti-nutritive factors like phytic acid.
Zinc bioavailability is key to prevent deficiencies, especially for plant-based eaters and those who may have trouble utilising and absorbing zinc. Intestinal absorption of zinc and its adequate utilisation by the body, in other words bioavailability, depend on several factors such as chemical form of zinc, dietary factors and physiological conditions. When supplementing with zinc, choosing sources that are highly bioavailable is important. Organic sources of zinc, for example citrates and gluconates, typically have higher bioavailability compared to their low soluble inorganic counterparts, such as zinc oxide.
For formulators bioavailability is not the only key factor; taste, mineral content, solubility and reactivity are also critical. Highly soluble salts like zinc sulfate and zinc acetate have a strong metallic, astringent and bitter off tastes that often need masking, plus their high reactivity may lead to unwanted side-reactions in the formula. Zinc oxide tastes better, however it is nearly insoluble and existing data indicates that its bioavailability is on the lower end in comparison with other zinc salts. Zinc citrate is a great solution for formulation as it is highly bioavailable, slightly soluble, low in reactivity, high in zinc content (31%) and has a relatively neutral taste when considering zinc salts.
Awareness of zinc continues to increase due to its various benefits to human health. Multiple forms of zinc are approved for use in food and dietary supplements, but many of them have drawbacks regarding taste and bioavailability. Please download our article for additional information.