Taking too much zinc from high dose zinc supplements can lead to symptoms such as nausea, vomiting, loss of appetite, diarrhea, abdominal cramps, and headaches. Jiang Zhao, Xingyou Dong, Xiaoyan Hu, Zhou Long, Liang Wang, Qian Liu, Bishao Sun, Qingqing Wang, Qingjian Wu, Longkun Li Zinc levels in seminal plasma and their correlation with male infertility: A systematic review and meta-analysis Sci Rep. (2016 Mar 2) Koehler K, Parr MK, Geyer H, Mester J, Schänzer W Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement Eur J Clin Nutr. (2009 Jan) Zinc lozenges are small tablets that are meant to dissolve slowly in your mouth. They’re typically taken for short periods to help reduce the symptoms and duration of the common cold. Afrin LB Fatal copper deficiency from excessive use of zinc-based denture adhesive Am J Med Sci. (2010 Aug)

Meanwhile, a study in pregnant women with iron deficiency found no significant difference in blood iron levels when comparing chelated iron (ferrous bisglycinate) with regular iron (ferrous sulfate) ( 8). Similarly, people who experience stomach pain after taking supplements may benefit from chelated minerals, as they’re less dependent on stomach acid for digestion. Only a few supplements have been shown to benefit testosterone production. Among those, the evidence mostly supports vitamin D and zinc, followed by magnesium. Two caveats should be kept in mind, however: Leproult R, Van Cauter E Effect of 1 week of sleep restriction on testosterone levels in young healthy men JAMA. (2011 Jun 1)Total cholesterol - Asbaghi O, Sadeghian M, Fouladvand F, Panahande B, Nasiri M, Khodadost M, Shokri A, Pirouzi A, Sadeghi O Effects of zinc supplementation on lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis. (2020-Jul-24) Seet RC, Lee CY, Lim EC, Quek AM, Huang H, Huang SH, Looi WF, Long LH, Halliwell B Oral zinc supplementation does not improve oxidative stress or vascular function in patients with type 2 diabetes with normal zinc levels Atherosclerosis. (2011 Nov)

The chelate effect is the greater affinity of chelating ligands for a metal ion than that of similar nonchelating (monodentate) ligands for the same metal. Gupta S, Brazier AKM, Lowe NM Zinc deficiency in low- and middle-income countries: prevalence and approaches for mitigation. J Hum Nutr Diet. (2020-Oct) Melville GW, Siegler JC, Marshall PW Three and six grams supplementation of d-aspartic acid in resistance trained men J Int Soc Sports Nutr. (2015 Apr 1) A Taravati, F Tohidi Association between seminal plasma zinc level and asthenozoospermia: a meta-analysis study Andrologia. (2016 Aug) When taken in supplement form at doses of less than 40 mg daily, zinc is unlikely to cause negative or harmful side effects.Zinc supplements vary in their dosages from 5–10 milligrams (mg) up to 25–45 mg, and sometimes higher. Dosages in the lower range are typically used as a daily preventative, whereas dosages in the higher range are typically used to treat chronic conditions and zinc deficiency. PMS Symptoms - Jafari F, Amani R, Tarrahi MJ Effect of Zinc Supplementation on Physical and Psychological Symptoms, Biomarkers of Inflammation, Oxidative Stress, and Brain-Derived Neurotrophic Factor in Young Women with Premenstrual Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial Biol Trace Elem Res. (2019 Jun 2) Nedeltcheva AV, Kilkus JM, Imperial J, Schoeller DA, Penev PD Insufficient sleep undermines dietary efforts to reduce adiposity Ann Intern Med. (2010 Oct 5)