Sodium and Potassium: What’s the Relationship?

Q. Please comment on the relationship between potassium and sodium.  How can I be sure that I’m not getting too much potassium as I continue to decrease the amount of sodium in my daily diet? 

A.  Decreasing the amount of sodium in your diet won’t necessarily affect the amount of potassium you’re getting but it will probably increase the ratio of potassium to sodium in your diet–and many believe that this is a good thing!

Sodium and potassium have complementary functions in the body, helping to regulate things like fluid balance and blood pressure.  We need to maintain a precise balance of potassium and sodium in our cells but our intake of potassium and sodium may vary greatly from day to day. Therefore, the body has systems that tightly regulate this balance, excreting any excesses into the urine.

The potassium/sodium content of our modern diet is radically different than the diet our ancestors ate–and many believe that this contributes to a lot of our modern health problems. Potassium is found in fruits and vegetables; most of the sodium we eat comes from processed and packaged foods.

By some estimates, our ancestral (pre-industrial) diet had a potassium to sodium ratio of at least 3:1, meaning that it contained about three times as much potassium as sodium.  However, as we’ve come to eat more and more processed foods and less fruits and vegetables, our intake of potassium has declined and our intake of sodium has skyrocketed.  The typical potassium to sodium ratio today is 1:3 (three times as much sodium as potassium) or exactly the inverse of our ancestral diet.

Whether or not the potassium/sodium ratio theory is correct, reducing your intake of processed foods and increasing your intake of fruits and vegetables is a great health upgrade for your diet!  I think  its pretty unlikely that you will get too much potassium from foods. Most Americans get about 2500 to 3000 milligrams per day; the recommended intake is about twice that!