1. SanchezA.The best zinc supplement.https://www.chicagotribune.com/consumer‐reviews/sns‐bestreviews‐health‐the‐best‐zinc‐supplement‐20190806‐story.html Accessed 2 February 2020
2. Oregon State University.Zinc deficiency linked to immune system response particularly in older adults.https://www.sciencedaily.com/releases/2015/03/150323142839.htm Accessed 2 February 2020
3. HaaseH RinkL.The immune system and impact of zinc during aging.https://immunityageing.biomedcentral.com/articles/10.1186/1742‐4933‐6‐9 Accessed 2 February 2020
4. Zinc requirements and the risks and benefits of zinc supplementation
5. Zinc-Induced Copper Deficiency