Nutritional Adequacy of Potassium & Magnesium of the Average American's Diet

Potassium and magnesium are two essential minerals that we receive from our diets. The two work together as electrolytes, helping to manage the fluid balance in the body. Magnesium is required for adequate processing of potassium, so a deficiency in one of the minerals can affect body stores of the other.

Potassium Deficiency

• Because so many foods contain potassium, actual dietary deficiency is rare for the average healthy American adult. However, excess intake of alcohol, coffee and sugar, and physical and mental stress can deplete potassium levels in the body.

Potassium RDA

• The Food and Nutrition Center of the Institutes of Medicine have established that 4.7 grams per day (4,700 milligrams) as the recommended dietary intake for potassium for adults. Women who are breastfeeding need 5.1 grams per day.

Foods High in Potassium

• Foods that are particularly high in potassium include bananas, potatoes, tomatoes, lima beans, dairy products, citrus fruits and some fish.

Magnesium Deficiency

• Because most of the foods high in magnesium are fresh fruits, vegetables and whole grains, reliance on convenience and processed foods can cause a diet to be lacking in magnesium. Other reasons for magnesium deficiency can be related to other dietary habits, such as consuming excess saturated fats, salt, sugar, coffee or tea, and dark colas that contain phosphoric acid.

Magnesium RDA

• For adult females who are not pregnant or breastfeeding, the recommended daily requirement of magnesium is 310 to 320 milligrams per day. Adult males need more: 400 to 420 mg per day. For pregnant or breastfeeding women, the range is 310 to 400 mg per day.

Foods High in Magnesium

• Most dietary magnesium comes from vegetables, such as dark green, leafy types including spinach, kale and collards. Other good sources include bananas, dried apricots, avocados, almonds and cashews, legumes, soy products and whole grains.