Sodium tends to grab more attention than other electrolytes because you lose a significant amount through excessive sweating. But sodium isn't the only electrolyte you may need to replace. It's just one of a group of minerals that have the ability to carry electrical charges through fluids in your body. When you drink a cup of milk, you get four important electrolytes: sodium, potassium, calcium and magnesium.
The Scoop on Electrolytes
After they're digested, some minerals dissolve into small particles called ions, which carry an electrical charge. While these ions support your metabolism a number of ways, their ability to conduct electricity makes them responsible for triggering and maintaining nerve impulses and muscle contractions. Your body strictly regulates the concentration of electrolytes in your system to ensure you have the amount necessary to maintain vital functions. When electrolyte levels get too low or too high, serious medical problems can develop.
Calcium Does More Than Build Bones
About 99 percent of the calcium in your body is found in your bones and teeth. The remaining 1 percent stays in your blood and in the fluids surrounding cells, where it works as an electrolyte. In this role, calcium regulates contraction and relaxation of muscles in blood vessels, stimulates nerves and triggers muscle contractions. These processes are so essential your body takes calcium out of your bones when levels in your blood drop. Adults should consume 1,000 milligrams of calcium daily. One cup of fat-free milk contains 299 milligrams, or 30 percent of your recommended daily allowance.
Sodium and Potassium Create a Balance
Sodium and potassium must work together to keep muscles and nerves functioning. Sodium also regulates the amount of water in your body. As the sodium in your system increases, the volume of water increases and blood pressure goes up. Potassium helps counterbalance sodium's impact. It lowers blood pressure by relaxing muscles in blood-vessel walls. Many Americans consume too much sodium and too little potassium, which increases the risk of cardiovascular disease, according to a study cited in the September 2012 issue of the "American Journal of Clinical Nutrition." One cup of fat-free milk supplies 7 percent of your recommended daily intake of sodium and 8 percent of the adequate intake of potassium.
Magnesium Supports Your Heart
Magnesium relaxes muscles in your heart and blood vessels, which in turn regulates your heartbeat and helps lower blood pressure. Researchers from the Harvard School of Public Health reviewed existing studies and found that higher levels of magnesium in the bloodstream reduced the risk of cardiovascular disease. To what extent magnesium might be used to prevent heart disease requires further research, according to their study, published in the July 2013 issue of the "American Journal of Clinical Nutrition." A 1-cup serving of fat-free milk contains 27 milligrams of magnesium. The recommended daily allowance for women is 320 milligrams, while men need 420 milligrams.
- MedlinePlus: Fluid and Electrolyte Balance
- Merck Manual Home Health Handbook: Electrolytes
- Linus Pauling Institute: Calcium
- USDA Nutrient Database: Milk, Nonfat, Fluid, Without Added Vitamin A and D
- American Journal of Clinical Nutrition: Sodium and Potassium Intakes Among U.S. Adults: NHANES 2003-2008
- Linus Pauling Institute: Potassium
- Linus Pauling Institute: Sodium
- Annals of Nutrition and Metabolism: Magnesium: Novel Applications in Cardiovascular Disease -- A Review of Literature
- American Journal of Clinical Nutrition: Circulating and Dietary Magnesium and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Prospective Studies
- Harvard School of Public Health: Too Much Salt, Too Little Potassium, Increases Risk of Death