Potassium

Potassium is a very interesting nutrient that we need in our bodies for good health. It is first a mineral, which means it helps to build strong bones, teeth, and muscles. It is also an electrolyte, which means it helps the body send electrical impulses.  

Differing concentrations of potassium and sodium, inside and outside cells, form a voltage across cells that is critical for nerve impulse transmission. These electrical messages help control muscle contraction and heart beats. Two vital functions for overall well being. Some research even suggests that 20 to 40% of the body's resting energy is allocated towards maintaining this potassium/sodium voltage gradient, underscoring the importance of potassium in overall health. 

The body cannot naturally produce potassium, so it is important to consume potassium-rich foods. Unfortunately, in the traditional Western diet, much more sodium is consumed than potassium, putting the body's preferred ratio at risk.

Musculoskeletal Health Benefits of Potassium

1. Potassium Boosts Bone Health

Increased potassium intake decreases the amount of calcium excreted in urine and increases the kidneys retention of calcium to recycle back to the body for further use.

The body requires a certain level of free calcium to function properly. If this optimal amount is not available than the body will use calcium stored in bones.

Removing calcium from bones weakens bones and increases the risk for fracture and osteoporosis.

Researchers from the United Kingdom investigated the influence of dietary potassium intake on bone density status and fracture risk in an adult population in the United Kingdom. The investigators found that higher intakes of  potassium were associated with greater heel bone density and a lower risk for hip fracture. (Hayhoe et al. Dietary magnesium and potassium intakes and circulating magnesium are associated with heel bone ultrasound attenuation and osteoporotic fracture risk in the EPIC-Norfolk cohort study. Am J Clin Nutr. 2015 Aug;102(2):376-84.)

2. Potassium Supports Muscle Health

The typical western diet is rich in protein and cereal grains. A side product of the breakdown of these types of foods is acid, primarily a type of sulfuric acid. Frequently, the kidneys are unable to remove the excess acid sufficiently and the acid builds up causing a state refereed to as mild metabolic acidosis.

The body functions best in a very narrow pH range and the launches various mechanisms to maintain an ideal pH.One common counter measure the body employs is to breaks down muscle to release the amino acid glutamate. Glutamate than travels to the kidneys where it is used to produce in ammonia. Ammonia is able to reduce the acid level by bonding with excess hydrogen atoms forming a ammonium that is then excreted in urine.

An unfortunate consequence of this mechanism to remove excess acid is the consequential loss of muscle mass and the increased risk for sarcopenia(extreme muscle loss and weakness), increased risk of falls, fracture, disability, and loss of independence.

Potassium can offer a solution to the build up of acid that obviates the body’s need to break down muscle.  Potassium pairs with bicarbonate to form a powerful base that neutralizes excess acid and reduces the risk of muscle loss and its associated disability and functional loss.

Investigators at Tufts University explored the association between potassium intake and lean body mass in older subjects. The researchers found that higher excretion of potassium, a reflection of greater potassium intake, was associated with higher muscle mass in older men and women. The authors concluded that higher intake of foods rich in potassium, such as fruit and vegetables, may favor the preservation of muscle mass in older men and women. (Dawson-Hughes B, Harris SS, Ceglia L. Alkaline diets favor lean tissue mass in older adults. The American journal of clinical nutrition. 2008;87(3):662-665.)

Other Health Benefits

There are other conditions that potassium may assist, although more research is needed and for some conditions results to date have been mixed. Those include:

  • Helping maintain a consistent blood pressure
  • Reducing the risk of cardiovascular disease
  • Reducing the risk of developing diabetes
  • Helping prevent infertility
  • Helping prevent a stroke
  • Aiding in the healing of digestive disorders.
  • Lowering the risk of developing certain cancers

Best Natural Sources of Potassium

Vegetables, especially green leafy varieties, and legumes are rich and nutritious sources of potassium.

Recommended Dietary Allowance (RDA)

The Food and Nutrition Board has developed a table of recommended dietary allowances (RDAs) of potassium, based on age and gender. 

These are the daily guidelines :

  • Infants up to six months old: 400 mg
  • Babies up to a year old: 700 mg
  • Toddlers up to three years old: 3,000 mg
  • Children up to eight years old: 3,800 mg
  • Tweens up to 13 years old: 4,500 mg
  • Teens up to 18: 4,700 mg
  • Adults over the age of 18: 4,700 mg
  • Pregnant people: 4,700 mg
  • Breastfeeding people: 5,100 mg

Precautions

Potassium from natural foods is generally well tolerated. RDA amounts can be obtained from a balanced, healthful diet. 

The FNB has not published an upper limit value. 

Excessive intake of supplemental potassium may cause GI symptoms, ingling of the hands and feet, and most seriously an abnormal heart rhythm. 

Any consideration a supplementation should be discussed with a qualified health professional familiar with your unique medical history.

References

Peterson LN. Potassium in nutrition. In: O'Dell BL, Sunde RA, eds. Handbook of nutritionally essential minerals. New York: Marcel Dekker, Inc; 1997:153-183.

Food and Nutrition Board, Institute of Medicine. Potassium. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, D. C.: National Academies Press; 2005:186-268.  (The National Academies Press)

New SA, Robins SP, Campbell MK, et al. Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health? Am J Clin Nutr. 2000;71(1):142-151.

Tucker KL, Hannan MT, Chen H, Cupples LA, Wilson PW, Kiel DP. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women. Am J Clin Nutr. 1999;69(4):727-736. 

Zhu K, Devine A, Prince RL. The effects of high potassium consumption on bone mineral density in a prospective cohort study of elderly postmenopausal women. Osteoporos Int. 2009;20(2):335-340. 

Morris RC, Frassetto LA, Schmidlin O, Forman A, Sebastian A. Expression of osteoporosis as determined by diet-disordered electrolyte and acid-base metabolism. In: Burkhardt P, Dawson-Hughes B, Heaney R, eds. Nutritional Aspects of Osteoporosis. San Diego: Academic Press; 2001:357-378.

Sebastian A, Harris ST, Ottaway JH, Todd KM, Morris RC, Jr. Improved mineral balance and skeletal metabolism in postmenopausal women treated with potassium bicarbonate. N Engl J Med. 1994;330(25):1776-1781.

Frassetto L, Sebastian A. Age and systemic acid-base equilibrium: analysis of published data. J Gerontol A Biol Sci Med Sci 1996;51:B91–B99.

Vazquez JA, Adibi SA. Protein sparing during treatment of obesity: ketogenic versus nonketogenic very low calorie diet. Metabolism 1992;41:406–414.

Garibotto G, Russo R, Sofia A, et al. Muscle protein turnover in chronic renal failure patients withmetabolic acidosis or normal acid-base balance. Miner Electrolyte Metab 1996;22:58–61.

Papadoyannakis NJ, Stefanidis CJ, McGeown M. The effect of the correction of metabolic acidosis on nitrogen and potassium balance of patients with chronic renal failure. Am J Clin Nutr 1984;40:623–627.

Frassetto L, Morris RC Jr, Sebastian A. Potassium bicarbonate reduces urinary nitrogen excretion in postmenopausal women. J Clin Endocrinol Metab 1997;82:254–259.

Williams B, Layward E, Walls J. Skeletal muscle degradation and nitrogen wasting in rats with chronic metabolic acidosis. Clin Sci 1991;80:457–462.

Longe, J., ed. The Gale Encyclopedia of Alternative Medicine, second edition, 2004. National Institute of Health Medline Plus: "Potassium." United States Department of Agriculture: "Dietary Reference Intakes: Electrolytes and Water."

FDA, CFSAN: "FDA-approved potassium health claim notification for potassium containing foods."

Natural Medicines Comprehensive Database: "Potassium."