What Is the Difference Between Calcium & Potassium?
Calcium and potassium are minerals essential to your diet. While they share some similarities – for example, both serve as electrolytes in your body – they have considerable differences in their chemical properties, physiological functions and dietary sources. Consult a dietitian or your health-care provider with specific concerns about your calcium or potassium intakes.
CHEMISTRY
Calcium ranks fifth in terms of abundance in the earth’s crust, making up 3 percent of its composition. It is a hard metal that reacts with both air and water. Calcium is not found as an isolated metal in nature, but rather bound with other elements, such as calcium carbonate or calcium chloride. Potassium comprises 1.5 percent of the earth’s crust and ranks seventh in abundance of crust components. A soft metal, potassium is very reactive. It oxidizes so readily it must be stored under argon gas or under oil to protect it from the air.
FUNCTION
Almost all the calcium in your body is located in your teeth and bones, providing structure to your body and protection for your internal organs. The remainder is spread throughout your body in your soft tissues and blood and is vital to cell signaling in support of muscular contraction and nerve impulse transmission. In this role, calcium functions as an electrolyte, a charged atom that can conduct electricity. Potassium is also an electrolyte, although potassium exists largely inside your cells while calcium is predominantly on the outside. Potassium functions to create a membrane potential, an electrochemical gradient that helps control the components that move in and out of your cells.
SOURCES
Your daily diet should include between 1,000 and 1,200 milligrams of calcium. Milk products are especially rich in this mineral, with 8 ounces of either milk or yogurt providing 300 milligrams. Plant sources of calcium include calcium-processed soy products, spinach, rhubarb and white beans.
You require an even greater amount of potassium in your everyday diet, 4,700 milligrams. Potatoes with their skin, prunes, raisins, lima beans, acorn squash and bananas are all good sources of potassium.
DEFICIENCIES
Your skeletal system serves as a calcium reservoir for your cellular needs. If your dietary calcium is low, your body pulls calcium from your bone tissue to maintain cellular function. If your calcium intake remains low for a prolonged period, your bones may become brittle as they slowly demineralize. Potassium deficiency affects the ability of your cells to signal appropriately, and can cause muscle weakness, fatigue and cramps. Low dietary potassium can also result in paralysis and an irregular heartbeat.