A medium-sized baked potato supplies milligrams of potassium, or 20 percent of the RDA of potassium for an adult. Severe potassium deficiency is most common in people who have absorption disorders like Crohn's disease, kidney disease, congestive heart failure, an eating disorder like anorexia or bulimia or any illness that causes frequent diarrhea and vomiting. It is also more likely in people who sweat excessively from physical exertion or from living in a hot climate.
Potassium deficiency, also known as hypokalemia, is characterized by bloating, muscle weakness, fatigue, abdominal pain, cramping and constipation.
If left untreated, hypokalemia may cause paralysis and potentially fatal heart arrhythmia. A diet that is rich in high-potassium foods like fresh fruits, vegetables and nuts is superior to supplementation when it comes to filling your potassium requirement, advises the Linus Pauling Institute.
Do not begin taking potassium supplements until you've first spoken to your doctor. Potassium supplements may cause nausea, diarrhea, vomiting and stomach pain. 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 ]. The potassium citrate salts significantly reduced the risk of new stones and reduced stone size.
However, the proposed mechanism involves citrate, not potassium per se; citrate forms complexes with urinary calcium and increases urine pH, inhibiting the formation of calcium oxalate crystals [ 52 , 56 ]. The authors of the AHRQ review [ 48 ] concluded that observational studies suggest an association between higher potassium intakes and lower risk of kidney stones. However, they also found the evidence insufficient to determine whether potassium supplements are effective because only one trial that addressed this question [ 55 ] met their inclusion criteria.
Additional research is needed to fully understand the potential link between dietary and supplemental potassium and the risk of kidney stones. Bone health Observational studies suggest that increased consumption of potassium from fruits and vegetables is associated with increased bone mineral density [ 57 ]. This evidence, combined with evidence from metabolic studies and a few clinical trials, suggests that dietary potassium may improve bone health. The underlying mechanisms are unclear, but one hypothesis is that potassium helps protect bone through its effect on acid-base balance [ 37 ].
Diets that are high in acid-forming foods, such as meats and cereal grains, contribute to metabolic acidosis and might have an adverse effect on bone. Alkaline components in the form of potassium salts potassium bicarbonate or citrate, but not potassium chloride from food or potassium supplements might counter this effect and help preserve bone tissue.
In the Framingham Heart Study for example, higher potassium intake was associated with significantly greater bone mineral density in elderly men and women [ 58 ].
In another study, the DASH eating pattern significantly reduced biochemical markers of bone turnover [ 59 ]. This eating pattern has a lower acid load than typical Western diets and is also high in calcium and magnesium, in addition to potassium, so any independent contribution of potassium cannot be determined. Only a few clinical trials have examined the effects of potassium supplements on markers of bone health. Potassium supplementation significantly increased bone mineral density at the lumbar spine and bone microarchitecture compared with placebo.
Conversely, a clinical trial in postmenopausal women aged 55—65 years found that supplementation with potassium citrate at either Overall, higher intakes of potassium from diets that emphasize fruits and vegetables might improve bone health. Although obesity is the primary risk factor for type 2 diabetes, other metabolic factors also play a role.
Because potassium is needed for insulin secretion from pancreatic cells, hypokalemia impairs insulin secretion and could lead to glucose intolerance [ 2 ]. This effect has been observed mainly with long-term use of diuretics particularly those containing thiazides or hyperaldosteronism excessive aldosterone production , which both increase urinary potassium losses, but it can occur in healthy individuals as well [ 2 , 10 , 16 , 65 ].
Numerous observational studies of adults have found associations between lower potassium intakes or lower serum or urinary potassium levels and increased rates of fasting glucose, insulin resistance, and type 2 diabetes [ ]. These associations might be stronger in African Americans, who tend to have lower potassium intakes, than in whites [ 68 , 71 ]. For example, one study of 1, adults aged 18—30 years without diabetes found that those with urinary potassium levels in the lowest quintile were more than twice as likely to develop type 2 diabetes over 15 years of follow-up than those in the highest quintile [ 68 ].
Among 4, participants from the same study with potassium intake data, African Americans with lower potassium intakes had a significantly greater risk of type 2 diabetes over 20 years of follow-up than those with higher intakes, but this association was not found in whites. Serum potassium levels were inversely associated with fasting glucose levels in 5, participants aged 45—84 years from the Multi-Ethnic Study of Atherosclerosis, but these levels had no significant association with diabetes risk over 8 years of follow-up [ 70 ].
Although observational studies suggest that potassium status is linked to blood glucose control and type 2 diabetes, this association has not been adequately evaluated in clinical trials. In a small clinical trial in 29 African American adults with prediabetes and low to normal serum potassium levels 3.
The findings from studies conducted to date are promising. Dietary potassium In healthy people with normal kidney function, high dietary potassium intakes do not pose a health risk because the kidneys eliminate excess amounts in the urine [ 1 ]. Although case reports indicate that very large doses of potassium supplements can cause heart abnormalities and death, the NASEM committee concluded that these reports do not provide sufficient evidence to set a UL [ 11 ].
In addition, there is no evidence that high intakes of potassium cause hyperkalemia in adults with normal kidney function or other adverse effects. Therefore, the committee did not set a UL for potassium. However, in people with impaired urinary potassium excretion due to chronic kidney disease or the use of certain medications, such as angiotensin converting enzyme ACE inhibitors or potassium-sparing diuretics, even dietary potassium intakes below the AI can cause hyperkalemia [ 11 ].
Hyperkalemia can also occur in people with type 1 diabetes, congestive heart failure, adrenal insufficiency, or liver disease [ 7 ]. Individuals at risk of hyperkalemia should consult a physician or registered dietitian about appropriate potassium intakes from all sources. Information on low-potassium diets is also available from the National Kidney Disease Education Program.
Although hyperkalemia can be asymptomatic, severe cases can cause muscle weakness, paralysis, heart palpitations, paresthesias a burning or prickling sensation in the extremities , and cardiac arrhythmias that could be life threatening [ 1 , 7 ].
Potassium from dietary supplements, salt substitutes, and medications Potassium supplements can cause minor gastrointestinal side effects [ 48 ]. Chronic ingestion of doses of potassium supplements e.
The use of potassium salts in certain medications has been associated with small-bowel lesions, causing obstruction, hemorrhage, and perforation [ 20 , 74 ]. For this reason, the FDA requires some oral drugs providing more than 99 mg of potassium to be labeled with a warning. Several types of medications have the potential to affect potassium status in ways that could be dangerous. A few examples are provided below. People taking these and other medications should discuss their potassium intakes and status with their healthcare providers.
These medications reduce urinary potassium excretion, which can lead to hyperkalemia. Experts recommend monitoring potassium status in people taking ACE inhibitors or ARBs, especially if they have other risk factors for hyperkalemia, such as impaired kidney function [ 75 ]. Experts recommend monitoring potassium status in people taking these medications, especially if they have impaired kidney function or other risk factors for hyperkalemia [ 78 ].
Experts recommend monitoring potassium status in people taking these medications, and initiating potassium supplementation if warranted [ 77 ]. The federal government's — Dietary Guidelines for Americans notes that "Because foods provide an array of nutrients and other components that have benefits for health, nutritional needs should be met primarily through foods.
In some cases, fortified foods and dietary supplements are useful when it is not possible otherwise to meet needs for one or more nutrients e. For more information about building a healthy dietary pattern, refer to the Dietary Guidelines for Americans and the U.
Department of Agriculture's MyPlate. This fact sheet by the Office of Dietary Supplements ODS provides information that should not take the place of medical advice. We encourage you to talk to your healthcare providers doctor, registered dietitian, pharmacist, etc. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.
Updated: March 26, History of changes to this fact sheet. Find ODS on:. Strengthening Knowledge and Understanding of Dietary Supplements. Health Information Health Information. Potassium Fact Sheet for Health Professionals. References Institute of Medicine. Washington, DC; Potassium intake, bioavailability, hypertension, and glucose control. Nutrients ;8. Sodium, chloride, and potassium. Present Knowledge in Nutrition.
Washington, DC: Wiley-Blackwell; Hinderling PH. The pharmacokinetics of potassium in humans is unusual. J Clin Pharmacol ; Water, electrolytes, and acid-based metabolism. Modern Nutrition in Health and Disease. Levene DL. Potassium chloride: absorption and excretion. Can Med Assoc J ; Potassium disorders: Hypokalemia and hyperkalemia. And if you do notice any of the previously stated symptoms, make sure to seek medical care immediately!
For people without kidney problems, the kidney is very good about controlling the right amount of potassium in the body. It is recommended that people with healthy kidneys take in at least 4. In early stages of kidney disease, problems with high potassium typically do not occur because the kidneys are still able to get rid of extra potassium. However, for people whose kidneys are not functioning normally, there comes a point when the kidneys can no longer remove extra potassium.
A buildup of potassium can be very dangerous. More research still needs to be done so that we understand how much potassium people with kidney problems should take in. The current recommendations by the National Kidney Foundation are that people with mild to moderate kidney disease not on dialysis take in 2 to 4 grams of potassium per day. However, this has not been well-studied yet and also in part depends on how severe your kidney function is or if you are on medications such as angiotensin converting enzyme inhibitors, angiotensin receptor blockers, or fluid pills which may raise or lower your potassium levels, and other factors.
If you have kidney disease, you should follow up with your doctor s and have your kidney labs checked regularly this includes your potassium level. The SAFE range of blood potassium levels is 3. If your level is lower or higher than this, you should talk to your doctor and to a kidney dietitian to find ways to get your potassium level into the safe range. You should also make sure that all of your doctors are aware of your kidney problem, because there are certain medications that you should avoid when you have kidney disease which can raise your potassium to high levels.
What if you have been told that your potassium level is on the high side and that you should limit your potassium intake? It is very important to speak with a kidney dietitian and with your doctor to discuss ways to limit your potassium intake if your potassium level is high or your kidney function is becoming severely impaired. Many fruits and vegetables, although otherwise healthy, are often high in potassium, and may need to be limited. Most people know that bananas and oranges are high in potassium, but other fruits that are high in potassium include: avocados, cantaloupe, papayas, honeydew melons and mangoes.
High-potassium vegetables include: potatoes, beans except green beans , spinach, tomatoes and winter squash. Milk products and chocolate are also high in potassium.
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