1. Petrus, E., 1998. Randomized, double-masked, placebo-controlled clinical study of the effectiveness of zinc acetate lozenges on common cold symptoms in allergy-tested subjects. Current Therapeutic Research 59(9): pp. 594-607.
2. Prasad, A., 2000. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate.
3. Science, M., 2012. Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials. CMAJ, 184 (10): E551-61.
4. Hemilä. H., 2011. Zinc may shorten the duration of colds: a systematic review. The Open Respiratory Medicine Journal. 5: pp.51-58.
5. Prasad, A., 2008. Duration and severity of symptoms and levels of plasma interleukin-one receptor antagonists, soluble tumor necrosis factor receptor and adhesion molecules in patients with common cold treated with zinc acetate. JID, 197 (15 March) pp.795-802.
6. Hemilä, H., 2015. The effectiveness of high doses zinc acetate lozenges on various common cold symptoms: a meta-analysis. BMC Family Practice. 16(24) pp. 2-11.
7. Mossad, S., 1996. Zinc gluconate lozenges for treating the common cold. A randomized, double-blind, placebo-controlled study. Ann Intern Med July 15; 125(2): pp. 81-88.
8. National Health and Nutrition Examination Survey, 2013. Online [available at]: http://wwwn.cdc.gov/nchs/nhanes/search/nhanes13_14.aspx Accessed May 25, 2015.
9. Holick MF: Vitamin D deficiency. N Engl J Med 2007; 357(3): 266-81.
10. The Linus Pauling Institute at Oregon State University, 2015. Online [available at]: http://lpi.oregonstate.edu/mic Accessed May 25, 2015.
11. Winkler, P. 2005. Effect of a dietary supplement containing probiotic bacteria plus vitamins and minerals on common cold infections and cellular immune parameters. Int J Clin Pharmacol Ther43 (7): 318-26.
12. Barringer, T., 2003. Effect of a multivitamin and mineral supplement on infection and quality of life: a randomized, double blinded, placebo-controlled trial. Annals of Internal Medicine. 138(5) pp.365-71.