he human body is approximately two-thirds water, the regulation and balance of which is critical to life. The electrolytes, a collective term referring to the three microminerals, sodium, potassium, and chloride, and carbon dioxide, are the primary movers in maintaining this important metabolic function.
he complexity of acid-base balance in the body’s various aqueous compartments, i.e., the acidity and/or alkalinity of the fluids both inside and outside of individual cells, goes somewhat beyond basic nutrition. It is important to be aware of this critical aspect of human metabolism, however, as it can be significantly effected by diet, and ultimately impact overall health.
The two important electrolytes, from a nutrition standpoint, are sodium and potassium. The minimum human requirement for sodium is about 200 mg/day, this much being essential for normal bodily functions. Natural sources of this mineral include vegetables and many animal food products. Sodium, of course, is also readily available as common table salt and, unfortunately, as an additive to flavor an endless number of packaged foods. In fact, its prevalence is so overbearing that most individuals must consciously monitor their diets to avoid consuming too much. The Recommended Daily Allowance (RDA) for sodium is 1100-3300 mg (Food and Nutrition Board, National Academy of Sciences, 1989). The current U.S. Food and Drug Administration (FDA) recommends a dietary intake of 2400 mg/day for adults.
The best guideline for potassium intake is to consume several times the amount of sodium in your diet. Because sodium and potassium work in concert metabolically, even adequate amounts of dietary potassium can be insufficient if sodium intake is excessively high. Potassium occurs naturally in a wide variety of foods. Some of the best sources are fruits (bananas, apricots, cantaloupe, and peaches), vegetables (broccoli, lima beans, sweet potatoes, and spinach), and fish (salmon, flounder and cod). The RDA (1989) for potassium is 1875-5625 mg, and the current dietary intake for adults recommended by the FDA is 3500 mg/day.
odium and potassium are on opposite poles of the water balance equation, resulting in the body’s attempt to regulate one based upon the level of the other. If sodium becomes elevated, your potassium level will drop, and visa-versa. Deficiencies in sodium are quite rare, due to its prevalence in the average diet, and potassium depletion generally occurs only when there is dehydration (from prolonged vomiting or diarrhea, for example), or possibly by a routine regimen of diuretic drugs.
he best remedy for depleted potassium, or diets high in salt, is to increase dietary intake of potassium. Potassium is often included in multivitamins, a good recommendation for many people, or as standalone supplements for individuals whose level of this electrolyte is chronically depleted, such as those whose medical care includes the routine use of diuretics, common among individuals taking medication for hypertension. If you are in the latter group, reducing your salt intake would be a much better remedy than considering potassium supplementation, unless recommended otherwise by your health care provider.
f consumed in excessive amounts, potassium is simply excreted in the urine. It is for this reason that individuals with kidney disease that would prevent this normal balance should consult with their health care provider before taking supplemental potassium.