Potassium chloride is used as a salt substitute, and efforts to reduce sodium intake likely will incorporate more uses of potassium chloride as a salt substitute in food. In fact, an IOM committee recently recommended that CDC consider, as a strategy for preventing and controlling hypertension in the U.S. population, advocating for the greater use of potassium/sodium chloride combinations as a means of simultaneously reducing sodium intake and increasing potassium intake (IOM, 2010).

While dietary guidance generally encourages increased intake of potassium (DGAC, 2005), this recommendation is in the context of healthy populations, most of whom would benefit from additional potassium in the diet.

However, there may be unintended consequences for a sizable subpopulation in the United States if potassium chloride is used widely and at high levels, especially since the potassium content of foods is not generally provided in label information. Adverse cardiac effects (arrhythmias) can result from hyperkalemia, which is a markedly elevated serum level of potassium. In individuals whose urinary potassium excretion is impaired by a medical condition, drug therapy, or both, instances of life-threatening hyperkalemia have been reported (IOM, 2005). There have been several case reports of hyperkalemia in individuals who reported use of a potassium-containing salt substitute while under treatment for chronic diseases (Haddad, 1978; Ray et al., 1999; Snyder et al., 1975).

Many Americans are taking medications that result in an increase in serum potassium. Angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and potassium-sparing diuretics are common drugs that can significantly reduce potassium excretion (DGAC, 2005). Medical conditions associated with impaired potassium excretion include diabetes, chronic kidney disease, end-stage renal disease, severe heart failure, and adrenal insufficiency. Individuals with these conditions are numerous in the U.S. population.

For the approximately 26 million Americans with chronic kidney disease (Lloyd-Jones et al., 2009), these increased serum levels may be exacerbated by widespread potassium chloride use. There may also be concern relative to people with hypertension using ACE inhibitors and ARBs, which are commonly prescribed and have been shown to cause hyperkalemia (defined in the study as serum potassium concentration > 5.5 mEq/L or mmol/L) in approximately 3.3 percent of those taking them (Yusuf et al., 2008). These drugs are also used in patients with diabetes who have microalbuminuria or frank proteinuria to decrease urinary protein excretion and protect their renal function.