People concerned about getting too much sodium in their diets will often try to cut it out entirely, checking food labels and recipes for any sign of added salt (sodium chloride). While this may be the prudent thing to do, especially if you have high blood pressure, there may be risks if you have too little sodium.
Role of Sodium
As much as sodium has been demonized in the American diet—mostly because we consume far too much—it actually plays as vital a role in the functioning of our bodies.
Sodium (like calcium, magnesium, phosphate, and potassium) is an electrolyte, meaning that it creates an electrically charged ion when dissolved in fluids like blood. Our bodies need electrolytes are they facilitate nerve impulses and regulate body functions such as heart rate, digestion, respiration, brain activity, and blood pressure.
For its part, sodium helps maintain the fluid balance in and around cells (including the volume of fluid in the blood) and helps regulate nerve and muscle function.
An excess amount of sodium—above 145 milliequivalents per liter (mEq/L)—can affect the fluid balance and contribute to high blood pressure. By contrast, the excessive loss of sodium (below 135 mEq/L) will not only decrease blood pressure but interfere with the activity of nerve cells and the muscles of the heart and digestive tract.
Causes of Sodium Deficiency
While you lose a little sodium every day when you sweat or urinate, it is generally not enough to cause a sodium deficiency unless you are severely malnourished. By and large, the foods we eat provide us with more than enough sodium to replace whatever we lost.