Potassium why is it needed

Normal serum concentrations of potassium range from about 3. Diarrhea, vomiting, kidney disease, use of certain medications, and other conditions that alter potassium excretion or cause transcellular potassium shifts can cause hypokalemia serum levels below 3.

Otherwise, in healthy individuals with normal kidney function, abnormally low or high blood levels of potassium are rare. Assessing potassium status is not routinely done in clinical practice, and it is difficult to do because most potassium in the body is inside cells.

Although blood potassium levels can provide some indication of potassium status, they often correlate poorly with tissue potassium stores [ 3 , 9 , 10 ]. Other methods to measure potassium status include collecting balance data measuring net potassium retention and loss ; measuring the total amount of potassium or the total amount of exchangeable potassium in the body; and conducting tissue analyses e. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people.

These values, which vary by age and sex, include:. The committee found the data insufficient to derive an EAR for potassium. Therefore, they established AIs for all ages based on the highest median potassium intakes in healthy children and adults, and on estimates of potassium intakes from breast milk and complementary foods in infats.

Table 1 lists the current AIs for potassium for healthy individuals. The NASEM committee also used an expanded DRI model to include a recommended intake level for a nutrient to reduce the risk of chronic disease, what they termed the chronic disease risk reduction intake CDRR [ 11 , 12 ].

According to the model, a CDRR might be set for a nutrient like potassium when there is a causal relationship between a certain level of intake and a reduced risk of chronic disease based on evidence of at least moderate strength. However, the committee found the evidence to be insufficient to derive a CDRR for potassium. Food Potassium is found in a wide variety of plant and animal foods and in beverages. Many fruits and vegetables are excellent sources, as are some legumes e. Meats, poultry, fish, milk, yogurt, and nuts also contain potassium [ 3 , 5 ].

Among starchy foods, whole-wheat flour and brown rice are much higher in potassium than their refined counterparts, white wheat flour and white rice [ 13 ]. Milk, coffee, tea, other nonalcoholic beverages, and potatoes are the top sources of potassium in the diets of U. Among children in the United States, milk, fruit juice, potatoes, and fruit are the top sources [ 15 ].

The forms of potassium in fruits and vegetables include potassium phosphate, sulfate, citrate, and others, but not potassium chloride the form used in salt substitutes and some dietary supplements; see supplements section below [ 16 ].

The U. Food and Drug Administration FDA developed DVs to help consumers compare the nutrient contents of foods and dietary supplements within the context of a total diet.

The DV for potassium is 4, mg for adults and children age 4 years and older [ 17 ]. FDA requires the new food labels to list potassium content. The — Dietary Guidelines for Americans also provides a list of foods containing potassium. Dietary supplements In dietary supplements, potassium is often present as potassium chloride, but many other forms—including potassium citrate, phosphate, aspartate, bicarbonate, and gluconate—are also used [ 18 ].

The Supplement Facts panel on a dietary supplement label declares the amount of elemental potassium in the product, not the weight of the entire potassium-containing compound. Some dietary supplements contain potassium iodide in microgram amounts, but this ingredient serves as a form of the mineral iodine, not potassium. Potassium-only supplements are also available, and most contain up to 99 mg potassium. Information on many dietary supplements that contain potassium is available in the Dietary Supplement Label Database from the National Institutes of Health, which contains label information from tens of thousands of dietary supplement products on the market.

First, the FDA has ruled that some oral drug products that contain potassium chloride and provide more than 99 mg potassium are not safe because they have been associated with small-bowel lesions [ 19 ]. Second, the FDA requires some potassium salts containing more than 99 mg potassium per tablet to be labeled with a warning about the reports of small-bowel lesions [ 20 , 21 ].

In accordance with a ruling by Congress, the FDA may not limit the amount of any nutrient, including potassium, in a dietary supplement, except for safety-related reasons [ 22 ]. However, the FDA has not issued a ruling about whether dietary supplements containing more than 99 mg potassium must carry a warning label [ 21 , 23 ].

Only a few studies have examined how well the various forms of potassium in dietary supplements are absorbed. According to an older study, liquid forms of potassium chloride used as drugs to treat conditions such as digitalis intoxication or arrhythmias due to hypokalemia are absorbed within a few hours [ 6 ]. Enteric coated tablet forms of potassium chloride designed to prevent dissolution in the stomach but allow it in the small intestine are not absorbed as rapidly as liquid forms [ 25 ].

Salt substitutes Many salt substitutes contain potassium chloride as a replacement for some or all of the sodium chloride in salt. The potassium content of these products varies widely, from about mg to 2, mg potassium per teaspoon [ 1 ]. Some people, such as those with kidney disease or who are taking certain medications, should consult their healthcare provider before taking salt substitutes because of the risk of hyperkalemia posed by the high levels of potassium in these products.

Dietary surveys consistently show that people in the United States consume less potassium than recommended, which is why the — Dietary Guidelines for Americans identifies potassium as a "nutrient of public health concern" [ 26 ]. According to data from the — National Health and Nutrition Examination Survey NHANES , the average daily potassium intake from foods is 2, mg for males aged 2—19, and 1, mg for females aged 2—19 [ 27 ].

In adults aged 20 and over, the average daily potassium intake from foods is 3, mg for men and 2, mg for women. Average potassium intakes vary by race. Non-Hispanic blacks aged 20 and older consume an average of 2, mg potassium per day. Average daily intakes are 2, mg for Hispanic whites and 2, mg for non-Hispanic whites [ 27 ]. Use of potassium-containing dietary supplements does not significantly increase total potassium intakes among U.

Insufficient potassium intakes can increase blood pressure, kidney stone risk, bone turnover, urinary calcium excretion, and salt sensitivity meaning that changes in sodium intakes affect blood pressure to a greater than normal extent [ 1 ]. Severe potassium deficiency can cause hypokalemia, serum potassium level less than about 3. Mild hypokalemia is characterized by constipation, fatigue, muscle weakness, and malaise [ 3 ]. Moderate to severe hypokalemia serum potassium level less than about 2.

Severe hypokalemia can be life threatening because of its effects on muscle contraction and, hence, cardiac function [ 5 ]. Hypokalemia is rarely caused by low dietary potassium intake alone, but it can result from diarrhea due to potassium losses in the stool. It can also result from vomiting, which produces metabolic alkalosis, leading to potassium losses in the kidneys. Magnesium depletion can contribute to hypokalemia by increasing urinary potassium losses [ 1 , 33 , 34 ].

It can also increase the risk of cardiac arrhythmias by decreasing intracellular potassium concentrations. In people with hypomagnesemia and hypokalemia, both should be treated concurrently [ 7 ]. Potassium inadequacy can occur with intakes that are below the AI but above the amount required to prevent hypokalemia. The following groups are more likely than others to have poor potassium status. People with inflammatory bowel diseases Potassium is secreted within the colon, and this process is normally balanced by absorption [ 35 ].

Inflammatory bowel diseases are also characterized by chronic diarrhea, which can further increase potassium excretion [ 36 ]. People who use certain medications, including diuretics and laxatives Certain diuretics e.

Potassium- sparing diuretics, however, do not increase potassium excretion and can actually cause hyperkalemia. Large doses of laxatives and repeated use of enemas can also cause hypokalemia because they increase losses of potassium in stool. People with pica Pica is the persistent eating of non-nutritive substances, such as clay.

When consumed, clay binds potassium in the gastrointestinal tract, which can increase potassium excretion and lead to hypokalemia [ 5 , 31 , 32 ]. Cessation of pica combined with potassium supplementation can restore potassium status and resolve symptoms of potassium deficiency. This section focuses on four diseases and disorders in which potassium might be involved: hypertension and stroke; kidney stones; bone health; and blood glucose control and type 2 diabetes.

Hypertension and stroke Hypertension, a major risk factor for coronary heart disease and stroke, affects almost a third of Americans [ 2 , 37 ]. According to an extensive body of literature, low potassium intakes increase the risk of hypertension, especially when combined with high sodium intakes [ 16 , ]. Higher potassium intakes, in contrast, may help decrease blood pressure, in part by increasing vasodilation and urinary sodium excretion, which in turn reduces plasma volume [ 1 ]; this effect may be most pronounced in salt-sensitive individuals [ 2 , 3 , 5 , 37 , 41 ].

The Dietary Approaches to Stop Hypertension DASH eating pattern, which emphasizes potassium from fruits, vegetables, and low-fat dairy products, lowers systolic blood pressure by an average of 5. Results from most clinical trials suggest that potassium supplementation reduces blood pressure. A meta-analysis of 25 randomized controlled trials in 1, participants with hypertension found significant reductions in systolic blood pressure by 4.

The supplements had the greatest effect in patients with hypertension, reducing systolic blood pressure by a mean of 6.

Two earlier meta-analyses of 19 trials [ 45 ] and 33 trials [ 46 ] had similar findings. However, a Cochrane review of six of the highest-quality trials found nonsignificant reductions in systolic and diastolic blood pressure with potassium supplementation [ 47 ]. In , the Agency for Healthcare Research and Quality AHRQ published a systematic review of the effects of sodium and potassium intakes on chronic disease outcomes and their risk factors [ 48 ].

The authors concluded that, based on observational studies, the associations between dietary potassium intakes and lower blood pressure in adults were inconsistent. They also found no evidence for an association between potassium intakes and the risk of hypertension. A similar analysis conducted by the NASEM committee that included 16 trials found that potassium supplements significantly lowered systolic blood pressure by a mean of 6.

However, the effects were stronger among studies including participants with hypertension; for studies including only participants without hypertension, the effects were not statistically significant. Based on 13 randomized controlled trials that primarily enrolled patients with hypertension, the AHRQ review found that the use of potassium-containing salt substitutes in place of sodium chloride significantly reduced systolic blood pressure in adults by a mean of 5.

However, reducing sodium intake decreased both systolic and diastolic blood pressure in adults, and increasing potassium intake via food or supplements did not reduce blood pressure any further. This finding suggests that at least some of the beneficial effects of potassium salt substitutes on blood pressure may be due to the accompanying reduction in sodium intake, rather than the increase in potassium intake.

Higher potassium intakes have been associated with a decreased risk of stroke and possibly other cardiovascular diseases CVDs [ 16 , 49 ].

However, the AHRQ review found inconsistent relationships between potassium intakes and risk of stroke based on 15 observational studies [ 48 ]. Any beneficial effect of potassium on CVD is likely due to its antihypertensive effects. However, some research shows a benefit even when blood pressure is accounted for.

These findings suggest that other mechanisms e. The FDA has approved the following health claim: "Diets containing foods that are a good source of potassium and that are low in sodium may reduce the risk of high blood pressure and stroke" [ 17 ]. Overall, the evidence suggests that consuming more potassium might have a favorable effect on blood pressure and stroke, and it might also help prevent other forms of CVD. However, more research on both dietary and supplemental potassium is needed before firm conclusions can be drawn.

Kidney stones Kidney stones are most common in people aged 40 to 60 [ 52 ]. Stones containing calcium—in the form of calcium oxalate or calcium phosphate—are the most common type of kidney stone. Low potassium intakes impair calcium reabsorption within the kidney, increasing urinary calcium excretion and potentially causing hypercalciuria and kidney stones [ 16 , 37 ].

Low urinary levels of citrate also contribute to kidney stone development. Observational studies show inverse associations between dietary potassium intakes and risk of kidney stones. Some research suggests that supplementation with potassium citrate reduces hypercalciuria as well as the risk of kidney stone formation and growth [ 52 , 55 ]. In a clinical trial of 57 patients with at least two kidney stones either calcium oxalate or calcium oxalate plus calcium phosphate over the previous 2 years and hypocitraturia low urinary citrate levels , supplementation with 30—60 mEq potassium citrate providing 1, to 2, mg potassium for 3 years significantly reduced kidney stone formation compared with placebo [ 55 ].

This study was included in a Cochrane review of seven studies that examined the effects of potassium citrate, potassium-sodium citrate, and potassium-magnesium citrate supplementation on the prevention and treatment of calcium-containing kidney stones in a total of participants, most of whom had calcium oxalate stones [ 52 ].

Having high sodium levels can increase the risk of high blood pressure. In healthy people, potassium lowers this risk by helping the body remove sodium. It also helps manage blood pressure by relaxing the walls of the blood vessels.

An adequate potassium intake may prevent or manage high blood pressure. And if a person has a high potassium intake and a low sodium intake, this may help reduce the risk of cardiovascular disease and stroke. Potassium may play a role in bone health. Studies have suggested that people who eat a lot of fruits and vegetables that contain potassium may have higher bone mineral density.

However, confirming this will require more research. If the finding is true, researchers will also need to discover the reason behind it and whether supplements have the same effect. A diet high in potassium may also help preserve muscle mass in older people and people who have health conditions that lead to muscle wasting. High calcium levels in the kidneys can result in kidney stones. Research from notes that switching to the DASH diet may help reduce the risk of kidney stones, as the diet favors foods that are rich in potassium and other essential nutrients.

However, people with kidney failure should not consume too much potassium, as it could have a negative impact. In this case, a doctor will recommend how much potassium to include in the diet. Potassium is present in many plant-based foods, but processing reduces the levels of this nutrient. Anyone with a diet high in processed foods may have a low potassium intake.

Many processed foods are also high in sodium, so a person with a highly processed diet may need to increase their potassium intake accordingly. Overall, dried fruits and pulses are good sources of potassium.

The table below shows specific amounts in 1 serving of various potassium-rich foods. In most cases, a healthy diet provides enough potassium, especially if the diet is low in sodium. Sometimes, a doctor may recommend supplements.

There is some evidence that these may help :. However, confirming that potassium supplements can help treat or prevent these health issues will require more research. Ask a doctor before using potassium supplements. This is especially important for people who have kidney disease or are also taking other medications. For an otherwise healthy person, a deficiency involves having potassium levels lower than 3. This cutoff point is lower for people with kidney disease. If potassium levels fall below 2.

It can lead to:. Learn more about potassium deficiencies here. However, excess potassium, or hyperkalemia, can be harmful for people with kidney problems if their kidneys are unable to remove enough potassium. An albuterol inhaler can also lower dangerously high levels. Calcium gluconate may be used temporarily to stabilize the heart and reduce the risk of serious heart complications from hyperkalemia.

Healthy kidneys are often enough to regulate body potassium. Medical conditions that affect levels should be monitored regularly. Call your doctor if you experience any unusual symptoms. Potassium helps regulate critical body functions, and a potassium-rich diet is linked to health benefits. Here's a review of potassium and what it…. Potassium is a mineral that's involved in muscle contractions, heart function and water balance. This article explains how much potassium you need per….

Potassium is an essential electrolyte, which is a mineral that your body needs to function correctly. However, high levels of potassium can be…. Low potassium levels in your blood can cause weakness, fatigue, and abnormal heart rhythms. Find out how to treat hypokalemia. Bananas make a great breakfast, snack, or dessert. Here are 11 impressive and evidence-based benefits of bananas. Multiple tests can analyze metabolism. Most need blood drawn, but some can be ordered online and done at home.

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What is potassium? Sources of potassium.