Potassium in Multivitamins

Potassium is essential for cellular functions throughout your body. This mineral works side by side with sodium to sustain a certain balance of fluid in and around all cells. As it’s balancing fluid, it conducts electricity through tissues to make your heart beat, allows muscles to contract and keeps your digestive tract moving. You need a large amount of potassium each day to support these processes, but because it can be devastating to your body in large doses, multivitamins only have a small amount.

In the United States, multivitamins do not have more than 99 milligrams of potassium, reports the Linus Pauling Institute. This limit is set for a couple reasons. First, it lessens your risk of overdosing on the mineral and suffering from potassium toxicity. Second, because you need a lot of potassium daily -- 4,700 milligrams -- putting the entire day’s worth of potassium in a single pill would make it too bulky.

When you read the nutrition facts label of your multivitamin, you may see potassium listed in a bunch of different forms. Watch for potassium chloride, fumarate, citrate, gluconate, bicarbonate, aspartate or orotate. Potassium is generally very well absorbed in your small intestine no matter which form is in your supplement, explains Dr. Elson M. Haas.

The majority of vitamins and minerals have a tolerable upper intake level, known as a UL, set forth by the Food and Nutrition Board of the Institute of Medicine. Because you’re not likely to get too much from your diet and supplements tend to have low concentrations of the mineral, potassium does not have a UL. If you’re taking a separate potassium supplement, you could quickly get way more than you need and throw your potassium-sodium balance out of whack. When potassium toxicity occurs, a condition known as hyperkalemia, your limbs become numb, your heart rate decreases and becomes weak and in severe cases, you could have a heart attack.

Since you’ll only get about 2 percent of the potassium recommendation from a single dose of your multivitamin, you’re better off relying on your diet to meet your needs. Fruits, beans, vegetables, nuts, seeds and fish are some of the richest sources of potassium. As an example, a large 7-ounce baked potato gives you 1,080 milligrams, a cup of seedless raisins offers 1,085, a 5.25-ounce banana provides nearly 540 milligrams and canned white beans have 1,190 milligrams per cup. You do lose potassium when you sweat profusely, so if you’re working out hard or spend a lot of time in the heat, drinking a sports beverage can quickly replenish any lost potassium.