If I proclaim that the human body has an electric charge, or has an electrical capacity, some people will look at me as if I’m from outer space, however, upon looking closely at a small, but abundant group of minerals, you’ll quickly realise that without these crucial elements, we couldn’t move a muscle, or breathe, or generate a heart beat, or conduct nerve signals, or in better words, our cells wouldn’t be able to communicate with each other. There are five key minerals that act as electrolytes, calcium, sodium, potassium, chloride and magnesium. Given that I have already devoted an article to magnesium, I will focus on the other four. 

Electrolyte	Physiological effects	Dietary sources
Calcium	All the minerals play a role in muscle function and metabolism, due to their role in facilitating contractions and nerve activity (Dronkelaar et al, 2017) Calcium has important functions in the nervous system, such as regulating release of neurotransmitters from presynaptic terminals, regulating gene expression, membrane excitability, dendrite development and synaptogenesis (Kawamoto et al, 2012) In cardiac myocytes, calcium is released intracellularly from the sarcoplasmic reticulum to enable muscle contraction. With every heart beat, the calcium concentration in the cytosol increases approximately 10-fold from a resting level. A defect in this process would likely impair the ability of heart muscle to contract and a defect in removing calcium from the cytosol could impair cardiac relaxation so both calcium deficiency and excess are probable factors that interplay in heart attack and failure (Marks, 2003) Calcium is integral to the structure of bone as calcium and phosphate ions fuse within matrix vesicles to form hydroxyapatite crystals, which rupture and spread to the surrounding matrix once they become supersaturated, forming the primary component of bone (Florencio-Silva et al, 2015)	Dairy products are the primary source, including milk, yoghurt, and cheese Other sources include tofu, sardines, salmon, and some leafy green vegetables, such as kale and broccoli (Hoque, 2023) Per 100 grams, tofu contains 1480 mg, cheddar cheese contains 739 mg, sesame seeds contain 670 mg, and tinned sardines contain 500 mg (stewartnutrition.co.uk, n.d)
Sodium and potassium	The functions of sodium and potassium are profound in human health, given that most metabolic processes are dependent on these electrolytes  The basis in which sodium and potassium mediate most of their chemical functions is through the sodium/potassium-ATPase pump, which moves potassium into the cell, whilst moving sodium out of the cell. This process influences fluid distribution between cells by osmotic forces and also generates an electrochemical gradient across cell membranes ( as mentioned below) (Zoroddu et al, 2019) Water, sodium (the main extracellular cation), and potassium (the main intracellular cation) move constantly between intracellular and extracellular body compartments to maintain internal fluid and electrolyte balance  The kidneys have a crucial role in maintaining the body’s acid-base balance and both sodium and potassium ions can replace hydrogen ions in the renal (kidney) tubule The flux of sodium and potassium generates an electrical potential that enables the conduction of nerve impulses and the electrical potential gradient created by the sodium-potassium pump, aids to generate muscle contractions and regulate the heartbeat (Pohl et al, 2013, p.32)	Sodium is found in a wide variety of foods but salt, or sodium chloride, is a primary source of sodium in the diet (Hoque et al, 2023) Potassium sources include milk, meat, bananas, raisins and prunes (Hoque, 2023) In regards to sodium, per 100 grams, tinned anchovies contain 3930 mg, bacon contains 1880 mg, ketchup contains 1630 mg, and feta cheese contains 1440 mg  In regards to potassium, per 100 grams, paprika contains 2340 mg, dried apricots contain 1380 mg, potato crisps contain 1060 mg, and raisins contain 1020 mg (stewartnutrition.co.uk, n.d)
Chloride	Chloride is the most abundant extracellular anion and plays critical roles in digestion, muscular activity, fluid balance, and acid-base balance (Morris & Mohiuddin, 2020) Essentially, chloride acts as a counter-ion for sodium and potassium, ensuring electro-neutrality under steady state and during transport across cellular membranes Together with it’s positively charged counter-ions, it serves as an important osmolyte (compound that influences properties of bodily fluids) that drives water across cellular membranes in cell volume regulation Chloride transport across cellular membranes generates electrical currents, therefore, chloride channels can change the voltage across plasma membranes and influence the electrical excitability of neurons, muscle, and endocrine cells (Jentsch & Pusch, 2018)

References

Dronkelaar, van C., Velzen, van A., Abdelrazek, M., Steen, van der A., et al. (2017). Minerals and sarcopenia: the role of calcium, iron, magnesium, phosphorus, potassium, selenium, sodium, and zinc on muscle mass, muscle strength, and physical performance in older adults: a systematic review. JAMDA,https://www.ageingmuscle.be/sites/ageingmuscle.be/files/Minerals%20and%20sarcopenia%20-%20the%20role%20of%20calcium,%20iron%20,%20magnesium%20….pdf

Florencio-Silva, R., Sasso, S.R.G., Sasso-Cerri, E., et al. (2015). Biology of bone tissue: structure, function, and factors that influence bone cells. BioMed research international, 2015, 421746.https://doi.org/10.1155%2F2015%2F421746

Hoque, M. (2023). A review on different dietary sources of important vitamins and electrolytes. International journal of research publication and reviews, 4(8), 731-736.https://www.researchgate.net/profile/Majedul-Hoque/publication/373741256_A_Review_on_Different_Dietary_Sources_of_Important_Vitamins_and_Electrolytes/links/64fc66153449310eb9b9ca96/A-Review-on-Different-Dietary-Sources-of-Important-Vitamins-and-Electrolytes.pdf

Hoque, M., Emon, K., Malo, P.C., Hossain, M.S., et al. (2023). Comprehensive guide to vitamin and mineral sources with their requirements. Indiana journal of agriculture and life science, 3(6), 23-31. https://doi.org/10.5281/zenodo.10284736

Jentsch, T.J., & Pusch, M. (2018). CLC chloride channels and transporters: structure, function, physiology, and disease. Physiological reviews, 98(3), 1493-1590. https://doi.org/10.1152/physrev.00047.2017

Kawamoto, E.M., Vivar, C., & Camandola, S. (2012). Physiology and pathology of calcium signaling in the brain. Frontiers in pharmacology, 3, 61,  https://doi.org/10.3389%2Ffphar.2012.00061

Marks, A.R. (2003). Calcium and the heart: a question of life and death. The journal of clinical investigation, 111(5), 597-600. https://doi.org/10.1172%2FJCI18067

Morris, A.L., & Mohiuddin, S.S. (2020). Biochemistry, nutrients. StatsPearls publishing. https://europepmc.org/article/NBK/nbk554545

Pohl, H.R., Wheeler, J.S. & Murray, H.E. (2013). Interrelations between essential metal ions and human diseases. Springer. https://link.springer.com/chapter/10.1007/978-94-007-7500-8_2

Stewartnutrition.co.uk. (n.d). Minerals.http://www.stewartnutrition.co.uk/treating_nutritional_deficiencies/minerals.html

Zoroddu, M.A., Aaseth, J., Crisponi, G., et al. (2019). The essential metals for humans: a brief overview. Journal of inorganic biochemistry, 195, 120-129.  https://doi.org/10.1016/j.jinorgbio.2019.03.013