Mineral Nutrient :: Potassium |
Acidic/Alkaline: | Alkaline-forming |
Content Below: | What is Potassium · Benefits · Deficiency Signs · Foods · Supplements · RDA · Toxicity |
What is Potassium ?
Potassium is a critical mineral that functions as an electrolyte in the body. Electrolytes conduct electricity when dissolved in water. Other related electrolyte minerals are sodium and chloride. All 3 work closely together to maintain the balance of body fluids, and regulate muscle contractions and nerve transmissions.
Potassium is also the third most abundant mineral in the body. There is at least twice as much of it as sodium, with 95% of it located inside cells. It works inside the cells, while sodium and chloride work in the fluid around the cells. Excess potassium is removed in urine by the kidneys.
Processing and cooking can significantly reduce potassium in food.
Potassium is one of the most important minerals that the body needs. It is essential for numerous metabolic processes, and the proper functioning of all organs, tissues, and cells, especially nerve and muscle cells.
There is overwhelming evidence that taking at least as much potassium per day as recommended in the RDA (for example from a diet high in foods with potassium) decreases the risks of osteoporosis, hypertension, stroke, and kidney stones.
This table summarizes the main ways that potassium benefits the body.
:: | Potassium Benefits & Functions |
1. | especially critical in the right amount for regulating nerve transmissions and muscle contractions, which involves the interchange of potassium and sodium in and out of nerve and muscle cells |
2. | needed for heart function and rhythm, and helps treat heart disorders |
3. | acts with sodium to control the body’s water balance |
4. | helps regulate the body’s electrolyte and acid-alkaline (pH) balance |
5. | helps the body handle sodium and so reduce risk of high blood pressure (studies have shown that those who take enough potassium based on the RDA have lower blood pressure, by significant levels in some cases) |
6. | a diet comprising high potassium foods lowers risk of stroke and heart attack by up to 40% |
7. | studies also show a correlation between bone mineral density and intake of potassium-rich foods that help to maintain the body’s pH (acid alkaline) balance so that less calcium needs to be mobilized from bone to do so, which preserves bone strength and prevents osteoporosis |
8. | involved in synthesis of protein from amino acids |
9. | needed for metabolism and storage of carbohydrates for use as energy by the muscles |
10. | needed for normal body growth and muscle-building |
11. | potassium citrate is known to dissolve calcium and so help prevent formation of kidney stones and calcification of soft tissues |
12. | large scale studies have shown that those who follow the RDA and take high potassium foods are 50 to 65% less likely to develop kidney stones than those who don’t, due to lower levels of calcium in the urine |
Potassium Deficiency Symptoms and Causes
Deficiency of potassium, or when blood levels of it drop too low, is known as hypokalemia.
Hypokalemia is not common, as high potassium foods are widespread. It can occur however. One reason is poor dietary intake due to bulimia or malnutrition. It can also result from malabsorption of nutrients from food due to intestinal tract problems such as inflammatory bowel disorders.
Other possible causes of hypokalemia are :
- medications that lead to potassium loss, such as certain antibiotics, steriods, and diuretics (“water pills” used to treat heart failure, high blood pressure, or fluid retention, that are possibly the most common cause of deficiency)
- excessive fluid loss due to excessive sweating, or prolonged diarrhea or vomiting, or overuse of coffee or laxatives
- over-consumption of herbal teas or black licorice or alcohol
- certain kidney and adrenal gland disorders
- low water intake
- over-exertion of muscles, for example in intense physical exercise
- stress induced hormones that decrease the potassium-sodium ratio within and outside cells
- a high salt or sodium diet increases potassium needed
Typical diets today, that are high in salt and low in potassium-rich foods like fruits and vegetables, contain twice as much sodium as potassium, in contrast to recommended intakes of 2 or 3 times more potassium than sodium.
People with severe hypokalemia, for example due to diarrhea followed by dehydration, may need potassium administered intravenously together with other salts. In severe cases, hypokalemia can lead to paralysis or death.
Researchers have also now realized that even mild hypokalemia can lead to potassium deficiency symptoms such as salt sensitivity and elevated blood pressure. It was found that people with diets chronically low in foods with potassium are prone to lower bone density, twitching, and muscle cramps, especially at night. Interestingly, mid-wives traditionally advise pregnant clients to eat bananas (which are rich in potassium) to avoid leg cramps.
Mild or moderate hypokalemia is often treated with potassium supplements or high potassium foods.
:: | Potassium Deficiency Symptoms |
1. | confusion or irritability |
2. | fatigue due to decrease in glycogen stored (especially in athletes) |
3. | muscle weakness or twitching or spasms |
4. | breakdown of muscle fibres |
5. | leg or other muscle cramps |
6. | muscular paralysis (one of the most severe potassium deficiency symptoms, arising from deficiency coupled with too much thyroid hormones in the blood) |
7. | shortness of breath or poor lung function (including lung paralysis in serious cases) |
8. | abnormal heart rhythms (arrhythmia), especially in those with heart disease |
9. | intestinal paralysis leading to constipation |
Potassium Foods
There are many foods with potassium, the richest sources being fruits and vegetables.
High potassium foods
· bananas · carrot juice, orange juice, passion-fruit juice, prune juice, tomato juice, coconut water · potatoes (especially the skin) · dried fruit (apricots, figs, dates, prunes, raisins).
Other foods with potassium include · blackstrap molasses · brewer’s yeast · legumes (adzuki beans, kidney beans, lentils, lima beans, pinto beans) · dairy products (milk, yogurt) · fennel, garlic, ginger, turmeric · fish (cod, flounder, halibut, salmon, sardines, tuna) · fruits (apricots, avocados, cantaloupe, citrus fruits, durian, kiwi fruit, papaya, passion fruit, peaches, strawberries) · meat and poultry · nuts · peanut butter · soybeans and soy products · sweet potatoes · vegetables (beet greens, bell pepper, broccoli, Brussel sprouts, cabbage, cauliflower, chard, cucumber, eggplant, kale, mustard greens, parsley, peas, spinach, tomatoes, winter squash) · whole grains including brown rice · rice and wheat bran · yam.
Potassium Supplements
Taking vitamins and minerals in their correct balance is vital to the proper functioning of all vitamins. They work synergistically, which means that the effectiveness of any one nutrient requires, or is enhanced, sometimes dramatically, by the presence of certain other nutrients.
For this reason, if you are looking to take supplements for maintenance of optimal health, the recommended approach is to take a multi-vitamin that has the proper balance of all the necessary nutrients your body needs.
For a list of reputable top ranked vitamin and mineral supplements chosen in an independent supplement review, see Best Multivitamin Supplements. Many of these are manufactured to pharmaceutical or nutraceutical GMP compliance, which is the highest multivitamin standard possible.
Keep in mind, however, that while mineral supplements are useful to plug nutritional gaps that are almost inevitable in modern diets, and to ensure we get optimal doses of nutrients, they are no substitute for a good diet. Instead, use them to complement a healthy diet and lifestyle.
Potassium RDA (Recommended Dietary Allowance)
The Food & Nutrition Board of the Institute of Medicine, National Academy of Sciences, in their 1997-2001 collaboration between the US and Canada, set the daily Adequate Intake (AI) of Potassium as follows.
Life Stage | Gender | Potassium Dosage | Day |
Infants 0-6 mths | 0.4* g |
Infants 7-12 mths | 0.7* g |
Children 1-3 yrs | 3.0* g |
Children 4-8 yrs | 3.8* g |
Girls 9-13 Yrs | 4.5* g |
Boys 9-13 Yrs | 4.5* g |
Females 14-18 Yrs | 4.7* g |
Males 14-18 Yrs | 4.7* g |
Females 19-50 Yrs | 4.7* g |
Males 19-50 Yrs | 4.7* g |
Females older than 50 Yrs | 4.7* g |
Males older than 50 Yrs | 4.7* g |
Pregnant Women 14-18 Yrs | 4.7* g |
Pregnant Women 19-50 Yrs | 4.7* g |
Lactating Mothers 14-18 Yrs | 5.1* g |
Lactating Mothers 19-50 Yrs | 5.1* g |
These dosages are the minimum required per day to ward off deficiency. In therapeutic use of this nutrient, dosage is increased as necessary for the ailment, keeping in mind Potassium toxicity levels.
Legend
1 µg = 1 mcg = 1 microgram = 1/1,000,000 of a gram
1 mg = 1 milligram = 1/1,000 of a gram
* Indicates AI figures based on Dietary Reference Intake (DRI) figures
Potassium Overdose Symptoms, Toxicity Level & Side Effects
Our bodies are usually able to maintain blood levels of potassium within a safe range. Normal intake of supplements and foods with potassium would not raise the level unduly.
However, certain circumstances can cause overly high potassium levels in the body, a condition known as hyperkalemia that is potentially harmful.
Possible causes of potassium overdose :
- the commonest cause is reduced renal (kidney) function, especially in patients undergoing dialysis due to kidney failure, as the kidneys play an important role in getting rid of excess potassium
- excessively high intake of potassium supplements or salts
- abnormal protein breakdown
- some medicines that inhibit the body’s ability to get rid of potassium
- severe infection
Potassium overdose symptoms include tingling sensations in the hands and feet, muscular weakness, and temporary paralysis.
Extremely high levels can lead to serious consequences such as rupture of blood cells, kidney or other tissue damage, irregular heartbeat (cardiac arrhythmia), or even a heart attack.
The Food and Nutrition Board of the Institute of Medicine did not establish a Tolerable Upper Intake Level (UL) for potassium. In the absence of an upper limit, keep closely to the RDA to avoid potassium overdose.
Do not take extra potassium except under medical guidance if you have hyperkalemia, or kidney problems, or Addison’s disease (an adrenal gland disorder). You might need to cut down on potassium-rich foods as well.
Women who are pregnant or breastfeeding should seek medical advice too, before taking any supplements.
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References
1. | Institute of Medicine, Food and Nutrition Board. Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. Washington, DC: National Academy Press; 2004. |
2. | U.S. National Libary of Medicine [NLM] & National Institutes of Health [NIH]: MedlinePlus. NLM-NIH home page. <http://www.nlm.nih.gov/medlineplus>. Use the built-in search function to find specific data. Accessed 2009 March – June. |
3. | The George Mateljan Foundation: The world’s healthiest foods [WHFoods]. WHFoods home page. <http://www.whfoods.com>. Accessed 2009 March – June. |
4. | Oregon State University, Linus Pauling Institute. Micronutrient Information Center [MIC]: Micronutrient research for optimum health. MIC home page. <http://lpi.oregonstate.edu/infocenter>. Accessed 2009 May. |
5. | Balch JF, Balch PA. Prescription for nutritional healing: A practical A-Z reference to drug-free remedies using vitamins, minerals, herbs & food supplements. Garden City Park, New York: Avery Publishing; 1990. |