Healthy Food Chart

Q. How much potassium do I need?

A.  The Daily Value (DV) for potassium is 3500mg per day. When you look at the nutrition detail for any food or recipe here on ND, you'll see the amount of potassium listed, along with the percentage of DV. 

The Daily Value is a sort of one-size-fits all
recommendation that is thought to represent the average needs of most
healthy people. In 2004, the Food and Nutrition Board of the Institute
of Medicine established an adequate intake (AI) recommendation for potassium based on
the amounts that have been found to lower blood pressure, reduce salt
sensitivity, and minimize the risk of kidney stones.  For adults, the
AI is 4700mg per day. (Tip: You can personalize your nutrient targets using My Preferences.)

Another reason to eat your vegetables!

Recent surveys show that most Americans fall short of the recommended amount of potassium. I think this is mostly because most people don't eat enough fruits and vegetables, which are high in potassium. (People whose diets are high in fruits and vegetables usually get two to three times the recommended amount.)

Severe potassium deficiency is usually caused by things
like severe vomiting or
diarrhea, bulimia, laxative abuse, or use of certain diuretic
medications.

The ratio of sodium to potassium is also something to think about. People who eat a high sodium diet may need more potassium than those who eat a low sodium diet. I discussed this at greater length in this post: http://blog.nutritiondata.com/ndblog/2009/03/sodium-and-pota.html.

For more information on potassium and health, see the Linus Pauling Micronutrient Information Center