Potassium is an essential mineral which is an important electrolyte in the body along with sodium and chloride. 95% of the body's potassium is concentrated intracellularly, whereas sodium is found mostly extracellularly. This balance is essential; if this balance didn't exist, too much water would accumulate inside cells causing them to burst. This balance between potassium and sodium is also crucial for maintaining electrical charge within the cell for proper electrical conduction in nerve cells and contraction in muscle cells.
Potassium is also critically important for the conversion of glucose into its storage form, glycogen. Exercising muscles rely on this storage form of glucose; when potassium is deficient, it produces fatigue and muscle weakness.
The following foods have the highest concentration of potassium. For a more expansive list on food sources of specific nutrients visit Health Canada's Dietary Reference Intakes for Elements or USDA's National Nutrient Database
Knowing about the amount of potassium in food sources is important, but even more important is knowing the potassium-sodium balance. High sodium diets have been linked to cardiovascular disease. This fact may be too narrow of an understanding. It may be more accurate to say that a high sodium, low potassium diet is linked to cardiovascular disease and that a low sodium diet is not always the therapeutic answer. On the flip side, a diet high in potassium and low in sodium may actually be therapeutic especially in the case of high blood pressure The average American diet will provide a potassium:sodium ratio of 1:2 when the recommended healthy ratio is actually 5:1. A diet rich in natural foods like fruits and vegetables would provide a ratio of 100:1 which is perhaps, optimal 
The following is a list of fruits and vegetables with high potassium:sodium ratios:
- Apples (90:1)
- Bananas (440:1)
- Carrots (75:1)
- Oranges (260:1)
- Potatoes (110:1)
Other food sources include:
Potassium has many important functions including: (1) water balance and distribution; (2) acid-base balance; (3) muscle and nerve cell function; (4) heart function; (5) kidney and adrenal function. The following is a list of the primary uses for potassium. 
- Potassium Depletion: Potassium depletion can occur with excessive diarrhea or vomiting and also with the use of certain diuretics. Because potassium concentrates, for the most part, intracellularly, potassium depletion which can be detected in the serum is already very serious. The consequences of potassium depletion are quite serious, so consult your naturopathic doctor if you suspect that your potassium levels are low.
- High Blood Pressure: A diet low in potassium and high in sodium is associated with high blood pressure. Many studies have shown that dietary potassium can lower blood pressure; other studies have shown positive results with the use of supplementation. One study showed that potassium supplementation can lower systolic blood pressure by 12mmHg and diastolic blood pressure by 16mmHg. Potassium supplementation as a treatment for high blood pressure in people over 65 years may be particularly useful as this population does not always responds to blood pressure-lowering medications.
- Cerebral Hemorrhage (Apoplexy): A diet which seeks to prevent stroke due to high blood pressure would contain the following: less salt, much more potassium (ideally in the form of fruits and vegetables but also supplementation when needed), much more magnesium, more calcium, much more vitamin C, and much less sugar .
Dietary potassium deficiency is typically caused by a diet low in fruits and vegetables and high in sodium. Potassium deficiency is often due to excessive fluid loss (sweating, diarrhea, or urination) or due to use of non-potassium sparing diuretics, laxatives, aspirin, and other drugs. The following is a list of signs and symptoms which might present with a potassium deficiency:
- muscle weakness
- mental confusion
- general weakness
- heart disturbances
- problems in nerve conduction and muscle contraction
Hyperkalemia (excess potassium) is the most serious adverse effect of potassium intake and occurs when the intake exceeds excretion leading to elevated serum potassium concentrations. This can occur with acute or chronic renal failure, hypoaldosteronism, the use of potassium-sparing diuretics, ACE inhibitors, or other drugs, and also with tissue damage which shifts potassium into circulation. Ingestion of 17g or more for someone not use to this dosage may become suddenly hyperkalemic even with normal renal function .
Best Specimens to Collect:
- Increasing potassium-rich foods is a good first step.
- Potassium excretion occurs largely by the kidney (80-90%) via the urine, adn the remainder is excreted in the sweat and stool. Since the kidney does not conserve potassium and will continue to excrete it, if inadequate amounts of potassium are not consumed on a daily basis, a potassium deficiency can occur.
- Potassium supplements can either be found as potassium salts (ex. chloride, bicarbonate etc.), bound to various mineral chelates (ex. aspartate, citrate etc.).
- The FDA restricts the amount of potassium available in non-food-based sources to 99mg/dose; however, the popular "salt substitute", NoSalt or Nu-Salt contains 530mg of potassium per 1/6 teaspoon.
- Potassium chloride is also available by prescription. It can cause nausea, vomiting, diarrhea, and ulcers. Dietary potassium does not produce these effects 
- The recommended dosages varies based on age and health status. To determine what your specific requirements are talk to your naturopathic doctor or other trained medical professional.
- Child: 3000mg (1-3 years); 3800mg (4-8 years); 4500mg (9-13 years)
- Adolescent: 4700mg (14-18 years)
- Adult: 2000mg (minimum) - 4700mg
- Children: Specific data on adequate potassium intake is lacking.
- Adults: Adverse effects of non-dietary potassium may include: GI symptoms (most commonly) with nausea, vomiting, abdominal discomfort, and diarrhea; ulcerations are much less frequent. Adverse effects are generally avoided when supplements are taken with meals.
- Pregnancy and Breastfeeding: Specific data on adequate potassium intake is lacking.
- Contraindications: Limited risk is associated with food-levels doses. Higher supplemental doses should be avoided without medical supervision especially those with Addison's disease, compromised renal function (especially chronic renal failure), heart block, peptic ulcers, GI ulceration or obstruction, acute dehydration, severe burns.
- Precautions: The Food and Nutrition Board of the U.S. Institute of Medicine states: "Overall, because of the concern for hyperkalemia and resultant arrhythmias that might be life-threatening, the proposed adequate intake of 4700mg per day (for adults] should not be applied to individuals with chronic kidney disease, heart failure, or type I diabetes, especially those who concomitantly use ACE inhibitor therapy. Among otherwise healthy individuals with hypertension on ACE inhibitor therapy, the adequate intake should apply as long as renal function is unimpaired" 
- Drug Interactions include:
- Supportive or Beneficial:
- Digoxin and Related Cardiac Glycosides - Hypokalemia increase risk of digoxin toxicity, but digoxin impairs potassium function and overdose can cause hyperkalemia. Consider co-administration of potassium, magnesium, and other nutrients which may prevent or correct adverse effects. Monitor, especially with diuretics and renal impairment.
- Quinidine and Related Antiarrhythmic Drugs - Hypokalemia of various origins can significantly increase risk of acute cardiac irregularities and adverse reactions to antiarrhythmic drugs, especially when accompanied by hypomagnesemia. Closely monitor electrolytes (especially potassium and magnesium whenever disturbed or depleted.
- Addresses Drug-Induced Deficiency:
- Albuterol/Salbutamol, Rimiterol, and Related Beta-2-Adrenoceptor Agonists - Oral and IV use can deplete potassium and other nutrients. Hypokalemia may ensue especially in combination with steroids or digoxin and may contribute to arrhythmias and aggravate asthma.
- Aminoglycoside Antibiotics - Drug can cause renal tubular damage and induce hypokalemia; renal failure is also potentiated by potassium depletion. Concurrent potassium may prevent or correct adverse effects.
- Amphotericin B - Drug can cause potassium depletion. Concurrent potassium may prevent or correct adverse effects.
- Carbonic Anhydrase Inhibitors - As a cautionary suggestion, concurrent potassium may prevent or correct adverse effects.
- Cisplatin - Renotubular damage is common with cisplatin and may cause wasting of potassium and other minerals. Concurrent potassium and magnesium may prevent or correct depletion.
- Colchicine - Drug may impair absorption and increase loss of potassium (and other nutrients). Co-administration of potassium and other nutrients may prevent or correct adverse effects.
- Corticosteroids, oral - Drug can deplete potassium which may contribute to edema, arrhythmias, or aggravate asthma. Consider co-administration of potassium and other nutrients.
- Diuretics, Potassium Depleting, Including Loop and Thiazide Diuretics - These drugs inherently increase risk of potassium depletion and hypokalemia. Concomitant ACE inhibitor therapy or other polypharmacy often used to mitigate depletion. Co-administration of potassium and other nutrients.
- Laxatives and Stool Softeners - These can deplete potassium and other nutrients more often with repeated use. Increased risk of adverse effects in cardiac patients especially on diuretics or other potassium-depleting drugs.
- Amiloride (Antikaliuretic-diuretic Agent) - This drug is a potassium sparing diuretic and there is a risk of hyperkalemia with significant increase in potassium intake especially with compromised renal function or while on ACE inhibitors. Limit potassium intake.
- Angiotensin-Converting Enzyme (ACE) Inhibitors - Significant risk of hyperkalemia when potassium is increased during drug use especially with compromised renal function or diabetes. Limit potassium intake.
- Beta-Adrenoceptor Antagonists - Drug can elevate potassium and potentially cause hyperkalemia. Potassium is generally contraindicated but may be indicated in certain circumstances (monitor).
- Cyclosporine - Drug-induced nephrotoxicity and other mechanisms can cause hyperkalemia, most often in patients with compromised renal function. Potassium is generally contraindicated but co-administration may be indicated. Caution is imperative.
- Losartan and Related Angiotensin II Receptor Antagonists - All angiontensin II antagonists inherently carry risk of hyperkalemia. Avoid extra potassium.
- Nonsteroidal Anti-inflammatory Drugs (NSAIDs) - Severe potassium-related adverse effects with NSAIDs are uncommon but not rare. Limit potassium intake and avoid rapid or significantly increased intake.
- Spironolactone, Triamterene - Potassium-sparing diuretics such as these carry implicit risk of hyperkalemia if potassium intake is significantly increased especially with compromised renal function and/or ACE inhibitor therapy. Limit potassium intake and avoid rapid and significantly increased intake.
- Trimethoprim-Sulfamethoxazole - Trimethoprim, with or without sulfamethoxazole can elevate potassium levels sometimes causing hyperkalemia. Limit potassium intake and avoid rapid or significant increased intake.
- Nutrient Interactions include 
- Magnesium and Magnesium-containing Antacids - Magnesium and potassium have an interdependent relationship. Magnesium depletion may be a cause of potassium depletion and is often needed to treat potassium repletion. Potassium administration may also increase the need for magnesium intake. It appears that the opposite is also true; increased magnesium may also increase the need for potassium. The risk of cardiac arrhythmias is the major concern if these electrolytes are not in balance and the risk is heightened in individuals taking potassium-depleting diuretics or digoxin or are at risk of potassium depletion via chronic diarrhea or vomiting.
- Herbal Interactions include 
- Diuretic Herbs - Diuretic herbs work much like diuretic medications work in that they can deplete potassium. There are also natural potassium-sparing diuretic plants such as dandelion.
- Ipecac - Ipecac is an emetic which can lower serum potassium levels.
- Licorice Root - In some susceptible people, licorice can cause "pseudoaldosteronism" characterized by elevated blood pressure, hypokalemia, and fluid retention.
- Senna - See Laxative and Stool Softeners in the "Drug Interactions" section above.
- Murray Michael T (2005) Encyclopedia of Nutritional Supplements, The Essential Guide for Improving Your Health Naturally, Prima Publishing
- Medlineplus 
- Hoffer Abram, Prousky Jonathan (2006) Naturopathic Nutrition, A Guide to Nutrient-Rich Food & Nutritional Supplements for Optimum Health, CCNM Press
- Stargrove Mitchell Bebell, Treasure Jonathan, McKee Dwight L (2008) Herb, Nutrient, and Drug Interactions, Clinical Implications and Therapeutic Strategies. Mosby
- Bralley J Alexander and Lord Richard S (2005) Laboratory Evaluations in Molecular Medicine, Nutrients, Toxicants, and Cell Regulators Institute for Advances in Molecular Medince, GA