Potassium
Overview
Potassium is a mineral that the body
needs to work normally. It helps nerves and muscles communicate. It
also helps move nutrients into cells and waste products out of cells.
A diet rich in potassium helps to offset some of sodium's harmful
effects on blood pressure. Most people get all the potassium they
need from what they eat and drink.
Too much sodium as is common in Western
diets that use a lot of salt, may increase the need for potassium.
Diarrhea, vomiting, excessive sweating, malnutrition, malabsorption
syndromes (such as Crohn's disease) can also cause potassium
deficiency, as well as use of a kind of heart medicine called loop
diuretics, mainly furosemide.
Tests
This test measures the amount of
potassium in the blood. Potassium is an electrolyte that is vital to
cell metabolism and muscle function. Potassium, along with other
electrolytes such as sodium, chloride, and bicarbonate (total
CO2), helps regulate the amount of fluid in the body, stimulates
muscle contraction, and maintains a stable acid-base balance.
Potassium is present in all body fluids, but most potassium is found
within your cells. Only about 2% is present in fluids outside the
cells and in the liquid part of the blood (called serum or plasma).
Because the blood concentration of potassium is so small, minor
changes can have significant consequences. If potassium levels are
too low or too high, there can be serious health consequences; a
person may be at risk for developing shock, respiratory failure, or
heart rhythm disturbances. An abnormal potassium level can alter the
function of neuromuscular tissue; for example, the heart muscle may
lose its ability to contract.
Why Get Tested?
To determine whether your potassium
level is within normal limits and to help evaluate an electrolyte
imbalance; to monitor chronic or acute hyperkalemia or hypokalemia
When to Get Tested?
As part of a routine medical exam, when
you have symptoms such as weakness and/or cardiac arrhythmia, or when
an electrolyte imbalance is suspected; at regular intervals when you
are taking a medication and/or have a disease or condition, such as
high blood pressure (hypertension) or kidney disease, that can affect
your potassium level
Recommended
Daily Allowance
Pediatric
- Infants birth - 6 months: 400 mg/day
- Infants 7 months - 12 months: 700 mg/day
- Children 1 -3 years: 3 grams (3,000 mg)/day
- Children 4 - 8 years: 3.8 grams (3,800 mg)/day
- Children 9 - 13 years: 4.5 grams (4,500 mg)/day
- Adults 19 years and older: 4.7 grams (4,700 mg)/day
- Pregnant women: 4.7 grams (4,700 mg)/day
- Breastfeeding women: 5.1 grams (5,100 mg)/day
An important note – other than the
small amount included in a multivitamin. Never take potassium
supplements except under a doctor's guidance. Do not give
potassium supplements to a child unless your doctor prescribes it.
Food
Sources
Good sources of potassium include
bananas, citrus juices (such as orange juice), avocados, cantaloupes,
tomatoes, potatoes, lima beans, flounder, salmon, cod, chicken, and
other meats. By
far the most well known source of potassium is the banana.
Precautions
With potassium it is always wise to
have a conversation with you doctor and only take potassium with the
supervision of your doctor. This is one supplement that has more
dangers than positives.
Possible
Interactions
“If you are
being treated with any of the following medications, you should not
use potassium without first talking to your health care provider.
Angiotensin
Converting Enzyme (ACE) Inhibitors: These drugs, including
benazepril, captopril, enalapril, fosinopril, lisinopril, moeexipril,
perdinodopril, quinapril, ramipril, trandolapril, may increase the
risk of hyperkaleimia.
Angiotensin
Receptor Blockers: Increased risk of hyperkalemia.
Potassium
Sparing Diuretics: These drugs, including amiloride, triamterene,
spironolactone, may increase the risk of hyperkalemia.
Indomethacin:
May increase the risk of hyperkalemia.
The following
medications may cause potassium levels to rise:
- Nonsteroidal anti-inflammatory drugs (NSAIDs): People who have poor kidney function and take NSAIDs are at higher risk.
- ACE inhibitors: These drugs treat high blood pressure, heart disease, diabetes, some chronic kidney diseases, migraines, and scleroderma. People who take ACE inhibitors and NSAIDs, potassium sparing diuretics, or salt substitutes may be particularly vulnerable to hyperkalemia (too much potassium). A rise in potassium from ACE inhibitors may also be more likely in people with poor kidney function and diabetes. ACE inhibitors include:
- Benazepril (Lotensin)
- Captopril (Capoten)
- Enlapril (Vasotec)
- Fosinopril (Monopril)
- Lisinopril (Zestril)
- Moexipril (Univasc)
- Peridopril (Aceon)
- Ramipril (Altace)
- Trandolapril (Mavik)
- Heparin (used for blood clots)
- Cyclosporine (used to suppress the immune system)
- Trimethoprimand sulfamethoxazole, called Bactrim or Septra (an antibiotic)
- Beta-blockers: Used to treat high blood pressure, glaucoma, migraines
- Atenolol (Tenormin)
- Metoprolol (Lopressor, Toprol-XL)
- Propranolol (Inderal)
The following
medications may cause potassium levels to decrease:
- Thiazide diuretics
- Hydrochlorothiazide
- Chlorothiazide (Diuril)
- Indapamide (Lozol)
- Metolzaone (Zaroxolyn)
- Loop diuretics
- Furosemide (Lasix)
- Bumetanide (Bumex)
- Torsemide (Demadex)
- Ethacrynic acid (Edecrin)
- Corticosteroids
- Amphotericin B (Fungizone)
- Antacids
- Insulin
- Fluconazole (Diflucan): Used to treat fungal infections
- Theophylline (TheoDur): Used for asthma
- Laxatives”
If you are taking any of these
medications, it is important for your doctor to test your potassium
levels to see whether or not you need a supplement. Do not start
taking a supplement on your own.
