Processed and prepared foods are among the highest sources of sodium in the North American diet. Examples include cold cuts, cheeses, instant meals, breads, fast foods and canned soups. Sauces and seasonings also contribute greatly to your daily intake. In combination with natural sources, these foods make it very easy to meet your daily sodium needs. As such, the most important concern when monitoring your sodium intake is to stay below a healthy daily maximum.
Sodium is one of the most important electrolytes in your body, contributing to the electrical transmission that is vital to the normal functioning of your muscles, nerves and cells. Sodium also helps to control the balance of fluids in your body. This function is important for maintaining both healthy blood volume and blood pressure. Most North Americans easily consume more sodium than they need each day, so you shouldn't be too concerned with meeting a daily minimum. However, if you're trying to restrict your sodium consumption, be careful to maintain an adequate intake to avoid diminishing its numerous important physiological functions.
RDA and Adequate Intake
A recommended dietary allowance is the amount of a nutrient necessary to meet the needs of approximately 98 percent of the population. Because of a lack of scientific evidence, there is no RDA for sodium. Instead, the Institute of Medicine uses an estimate called the "adequate intake," stating that 1.5 grams per day should be enough to meet most women's daily needs. However, this AI value is not as precise as the RDAs for most nutrients and doesn't necessarily apply to the same percentage of the population. As such, it is possible that you need more than a minimum of 1.5 grams of sodium per day.
Tolerable Upper Limit
In addition to AI and RDA values, the Institute of Medicine recommends tolerable upper limits for most nutrients. This is the maximum amount that most people's bodies can handle without any negative side effects. Sodium's TUL is 2.3 grams, or approximately the same amount that is present in 1 teaspoon of table salt. Although this is a healthy maximum for most people, you shouldn't use the TUL to guide your daily intake. This is because many unexpected foods contain modest amounts of sodium, with common examples including milk and vegetables. Aiming for a daily maximum that is slightly below the TUL -- for example, 2 grams per day -- leaves room for error and helps you to avoid the risks of eating too much sodium.
Regularly eating more than the TUL of sodium can lead to the development of high blood pressure. This is one of the most important risk factors for cardiovascular disease, which is responsible for one in four deaths among North American women. In addition, too much sodium can cause the buildup of excessive amounts of fluid in your body. These problems are particularly pronounced among people with kidney problems, as your kidneys are responsible for regulating your body's sodium levels. To avoid the risks of having too much or too little sodium, you should always consume between 1.5 and 2.3 grams of sodium per day.
Matthew Lee has been writing professionally since 2007. Past and current research projects have explored the effect of a diagnosis of breast cancer on lifestyle and mental health and adherence to lifestyle-based (i.e. nutrition and exercise) and drug therapy treatment programs. He holds a Master of Arts in psychology from Carleton University and is working toward his doctorate in health psychology.