What is Potassium?
Potassium is an alkali metal, its chemical element with formula is K. Although potassium does not dissolve in water it reacts intensely and rapidly with water, forming potassium hydroxide solution and hydrogen gas. In our bodies potassium is an important mineral, also known as electrolyte (K+), meaning that it is highly reactive with water.1
How does Potassium react with water?
The reaction between potassium and water leads to alkaline potassium being dissolved in water, creating positively charged K+ particles.1,5 These charged particles gain the ability to conduct electricity, which is very important in numerous biological processes occurring in the body.
Like other electrolytes such as sodium and calcium, potassium maintains appropriate levels of salt and water (osmotic balance) between cell membranes and intracellular body fluids (ICF). ICF is composed of water, electrolytes and non-electrolytes. Importantly, potassium levels should be constantly balanced with its opposite mineral, sodium. While potassium is also stored within cells, such as brain tissue, red blood cells and muscles, sodium is profoundly found in ICF, the fluid that surrounds cells.
This creates osmotic balance by maintaining appropriate electrical balance within our bodies. Tight control of electrolyte levels allows it to manage body water levels, move nutrients throughout the body, send nerve signals, support muscle contractions, as well as get rid of waste. The shift in potassium-to-sodium equilibrium towards either mineral can have serious health implications.
For instance, not enough consumption of potassium and too much sodium can increase one’s blood pressure, causing hypertension. Hypertension is known as a “silent killer” because it significantly increases the risk of heart diseases including stroke and heart attack. This is due to the increased blood pumping output which causes heart muscles to work harder and therefore wear out quicker.
Health benefits of potassium
The recommended dietary potassium requirement is approximately 2,000-3,700 mg per day.2 Importantly, consumption of a potassium-rich diet has been associated with improved overall health, mainly because it reverses water retention, thus reducing blood pressure; especially in the context of a high-sodium diet.3 Based on evidence from 30+ clinical trials and numerous cohort studies reviewed by the 2005 Dietary Guidelines for Americans Advisory Committee, this diet has a protective nature against stroke and other heart-related diseases.3
Interestingly, this positive correlation has been stronger when the mode of potassium intake is coming from supplements rather than foods. Additionally, building evidence suggests that increased potassium intake can improve bone density and prevent osteoporosis. The surge of charged potassium particles seems to form organic salts that benefit the skeleton by maintaining a healthy acid-base balance. Other benefits include the reduced occurrence of kidney stones and improved sensitivity to insulin in diabetics.4 Similarly, the rise in acidity favours calcium buildup in the kidneys, while potassium helps to maintain acidity in the tissue, subsequently preventing the formation of kidney stones.
There are limited studies available in regards to the bioavailability of potassium via dietary means. Essentially this means it is not clear how much potassium present in the food, actually gets absorbed by the body.2,4 People struggling with a severe deficiency may need to increase potassium intake in the form of supplements. Potassium medication can only be done under the supervision of a physician since it is associated with potentially dangerous side effects.
Side effects of potassium in medication
Despite the evident benefits of potassium, extremely high levels of the mineral (a condition referred to as hyperkalemia) can cause severe health problems and worsen pre-existing medical conditions. An appropriate dosage of potassium is therefore critical and has to be closely regulated. Inappropriately high doses of potassium supplements can cause side effects such as:
- Muscle weakness
- Heart murmurs
- Digestive issues
- Low blood pressure
Hyperkalemia is treated by medications or with dialysis, which helps to boost kidney function and remove excessive potassium along with other waste products from the blood.5
Potassium is found in most types of food, including :
- Green vegetables – broccoli, parsnips, spinach, peas and brussels sprouts
- Nuts and seeds
Figure: Potassium-Rich Foods
Created by Aastha Malik
Potassium is a key electrolyte involved in the normal functioning of all tissues in the body. It is important to ensure that potassium levels are maintained at appropriate levels at all times through eating a nutritious and balanced diet.
Potassium supplements are recommended in more severe deficiencies, and can potentially cause harm to the health, therefore has to be monitored by a doctor.
Taking 2,000-3,700mg of potassium supplements is highly unlikely to cause side effects.
- Potassium (K) and water. Potassium (K) and water [Internet]. Lenntech.com. 2022 [cited 12 August 2022]. Available from: https://www.lenntech.com/periodic/water/potassium/potassium-and-water.htm
- National Health Service UK. Vitamins and minerals - Others [Internet]. nhs.uk. 2022 [cited 12 August 2022]. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/others/
- Weaver C. Potassium and Health. Advances in Nutrition. 2013;4(3):368S-377S.
- Stone M, Martyn L, Weaver C. Potassium Intake, Bioavailability, Hypertension, and Glucose Control. Nutrients. 2016;8(7):444.
- Lanham-New S, Lambert H, Frassetto L. Potassium. Advances in Nutrition. 2012;3(6):820-821.