Vitamins, Minerals and Dietary Supplements
What is potassium?
Potassium is an essential mineral that is involved in both electrical
and cellular functions. Although it is a mineral, in the body it is classified
as an electrolyte. It is the primary electrolyte found in intracellular
fluid.
Why do we need it?
Potassium is an important factor in the regulation of water balance,
acid-base levels and blood pressure. It plays a vital role in the transmission
of nerve impulses and the building of muscle tissue. It is also required
for carbohydrate and protein metabolism.
How much potassium should I take?
According to the National Academy of Sciences, the recommended daily
allowance (RDA) for potassium is as follows:
- Adult men: 2000 milligrams/day
- Adult women: 2000 milligrams/day
- Children aged 7-10: 1600 milligrams/day
- Infants: between 500-700 milligrams/day
- Pregnant/lactating women: 2000 milligrams/day
What are some good sources of potassium?
Fish such as salmon, cod, flounder, and sardines are good sources of
potassium. Vegetables such as broccoli, peas, lima beans, tomatoes, potatoes
(especially potato skins), and leafy green vegetables such as spinach,
lettuce and parsley contain potassium. Apples, bananas and apricots are
also good sources (dried apricots contain more potassium than fresh apricots).
What can happen if I don't get enough potassium?
Potassium deficiency is uncommon in the United States. However, a variety
of factors can cause the loss of potassium from the body, including vomiting,
diarrhea, and the taking of certain diuretic drugs.
Moderate potassium deficiency can result in a variety of conditions,
including hypertension, congestive heart failure, cardiac arrhythmias,
depression and fatigue. Severe deficiency may cause decreased heart rate,
extreme muscle weakness, bone fragility and, if left untreated, death.
What can happen if I take too much potassium?
Excess potassium intake can cause a condition called hyperkalemia. Symptoms
include weakness, irregular heartbeat, a slow or absent pulse, paralysis,
kidney failure and, in extreme cases, respiratory arrest.
References
- Recommended Dietary Allowances, 10th ed. Washington,
D.C.: National Academy Press, 1989.
- Whelton PK, et al. Effects of oral potassium on blood
pressure. JAMA 1997;277:1624-1632.
- Sacks FM, Willett WC, Smith A, Brown LE, Rosner B,
Moore TJ. Effect on blood pressure of potassium, calcium, and magnesium
in women with low habitual intake. Hypertension Jan 1998;31(1):131-138.
- Young DB, Lin H, McCabe RD. Potassium's cardiovascular
protective mechanisms. Am J Physiol Apr 1995;268(4 Pt 2):R825-R837.
- Ettinger B, et al. Potassium magnesium citrate
is an effective prophylaxis against recurrent calcium oxalate nephrolithiasis.
Journal of Urology 1997;158:2069-73.
