Potassium: Interactions

Interactions of potassium with other micronutrients (vital substances):

Calcium

Potassium can also influence calcium metabolism. For example, high potassium intake prevents increased renal calcium excretion, which is often a consequence of high saline intake. Potassium thus promotes calcium retention in the kidney. It is possible that potassium contributes to reduced calcium removal from the bones and thus has a positive effect on bone metabolism. Since potassium can influence the acid-base balance, administration of an alkalizing potassium salt (e.g. potassium bicarbonate or tripotassium citrate) leads to a reduction in renal net acid excretion. This increased the calcium and phosphorus balance and decreased bone resorption, especially in postmenopausal women. To prevent adverse effects on bone metabolism, regardless of potassium intake, neutralization of mild metabolic acidosis resulting from a diet high in animal protein and table salt and low in fruits and vegetables is essential.

Magnesium

Magnesium and potassium are quantitatively the most important elements in the intracellular space, with magnesium being the second most abundant intracellular cation. Because of this, magnesium homeostasis is closely related to potassium homeostasis. Significant cation losses occur with gastrointestinal disorders – malabsorption, vomiting, diarrheadiuretics, alcohol, and antibiotics. Resulting magnesium deficiencies increase renal potassium losses – but their mechanism is unclear.In addition, hypomagnesemia increases the permeability of potassium through K+ channels, resulting in an unequal ratio between extracellular and intracellular potassium, with negative effects on cardiac muscle action potential. Accordingly, the interactions of potassium and magnesium involve gastrointestinal absorption, renal excretion, and endogenous distribution between extracellular and intracellular compartments, as well as various cellular processes.

Sodium

Potassium is mainly localized in the intracellular space of the human body. There it is more than 30 times more concentrated than in the extracellular fluid. In contrast, sodium is predominantly located outside the body cells in the body fluid, including the blood volume. Sodium is about 10 times more concentrated in the extracellular space than in the intracellular space.The different concentrations between potassium and sodium on the respective sides of the cell membrane result in an electrochemical gradient known as membrane potential. This is essential for cell excitability, nerve signal transmission, muscle contraction and nerve function, among other things. To maintain this membrane potential, the sodium-potassium ratio of the diet or a balance between sodium and potassium is extremely important.Excessive sodium intake can result in a deficiency of potassium. According to epidemiological studies, there is a close correlation between potassium and sodium intake and blood pressure and increased risk of apoplexy (stroke). Potassium has the greatest importance in the non-pharmacological regulation of blood pressure. In a meta-analysis with both hypertensive and normotensive subjects, the influence of potassium supplements (60 to 200 mmol/day, i.e. an amount of 2,346-7,820 mg) on blood pressure was investigated. The result was a clear reduction in blood pressure (systolic average of 3.11 mmHg and diastolic average of 1.97 mmHg).However, in normotensive subjects – persons with normal blood pressure – the effect was less than in hypertensive patients. In the studies in which the subjects had a high sodium intake at the same time, the treatment success was greater.A metaregression analysis of a total of 67 clinically controlled studies concluded that sodium reduction and increased potassium intake can make a significant contribution to the prevention of hypertension (high blood pressure). However, other studies that examined the effect of potassium and sodium intake on blood pressure produced unconvincing or contradictory results.A larger clinical intervention study of hypertensive men treated with antihypertensive medications who consumed 3,754 mg of potassium daily and very small amounts of sodium showed no association between potassium and sodium intake and elevated blood pressure. Furthermore, the level of potassium intake affects salt sensitivity (synonyms: salt sensitivity; saline sensitivity; saline sensitivity). Low potassium intake is associated with high sensitivity to common salt. Conversely, this is suppressed in a dose-dependent manner when dietary potassium intake is increased. Finally, a high-potassium diet, especially in individuals with marginal potassium intake, can reduce salt sensitivity and thus prevent or delay the onset of hypertension.