Most individuals meet people meet their daily hydration (water) requirements by obeying their sensation of thirst. Daily recommended intake of water for females is approximately just over 2 and a half litres. For males, just over 3 and a half litres is sufficient. Keep in mind that this amount of water is "total water". In other words, water contained in all consumed drinks and food. Each food contains a different percentage of water content. For example, when we chew a grape we can readily detect the water contained. A slice of bacon, however, will contain mostly protein and fat in comparison to a fruit or vegetable. Therefore, if you are consuming a diet with low water content, it is prudent to follow up with a little extra water. In fact, if you are trying to decrease you weight, water is essential, considering the water molecule is required to split fat molecules.

Notice that we did not set an upper limit for water intake. This is becuase we can estimate averages of intake by measuring the quantity of water an individual consumes through both drinks and food. However, different people have different lifestyles and will lose more water from their bodies than others. Take the individual who exercises daily. Sweating during a workout can result in water loss of more than a litre per hour. Those who work outdoors in very cold temperatures will also lose water through exhaling. Because the partial pressure of water is higher in the "warm" lung in comparison with the lower partial pressure of water in a cold environment, while we are breathing we are exhaling water vapour. We can easily see this when we breathe by looking at the cloud of vapour that exits our mouths as we breath on a cold winters day. To children it looks like smoke. During strenuous work in cold climates we can lose a litre or more water per hour through exhalation.

Dietary habit also dictates water loss. An individual consuming caffeine-containing drinks will lose more water through urination than someone drinking pure water. This is because caffeine is a substance which acts a diuretic (causes the kidney to expel water). Therefore, even though a cup of moderately strong coffee contains mostly water, the caffeine contained in the drink causes the kidneys to remove water consumed. When interviewing patients appearing dehydrated, most claim that they drink "lots and lots" of water. However, when we look more closely and find out what drinks they consume, we usually find that they are consuming caffeine-containing drinks such as sodas, coffees, teas, etc. Of course, the solution to this would be to simply drink decaffeinated drinks.

Sodium and potassium

The average healthy adult should consume approximately 1 and a half grams of sodium and 2 and a third grams of chlorine (chloride) per day. Since you would not be able to take pure chlorine or sodium, we rely on the combination of salt (a combination of sodium and chloride. The amount of salt required to give adequate amounts of sodium of and chloride, is just under 4 grams of salt. This helps to replace what is lost through the kidneys (producing urine), through sweat, and other mechonisms.

Electrolytes such as sodium are essential for conduction of nervous impulses and regulating osmolarity (solutes attracting water). Without sodium, the sugar glucose is not properly absorbed through the gastrointestinal tract. There is most likely some type of co-transport system in the intestinal wall requiring adquate concentration of sodium to be able to transport glucose. Calculating daliy salt intake requires a bit of detective work. Not only must we calculate how much we use on our foods, but also what is contained in foods, whether fresh or processed. Processed foods should contain carefully labelled information in regards to how much salt is added to the product. Freshly cooked foods also contain salt. This is easily overcome by referring to food charts, which display the average percentages of components (vitamin, mineral, protein, fat, carbohydrate content) of a particular foodstuff.

Different countries have slightly different RDA's for electrolytes. Western RDA's estimate the tolerable upper limit at just under 6 grams of salt per day. Most westerners in excess of this amount, and on average consumes more than 10 grams per day (salt contained in foodstuffs and added salt). So, what do we do? We can use a few simple guidelines to maintain a healthy balance. Eating more freshly cooked foods ensures that we will be consuming an excessive amount salt, such as contained in mainy processed foods. Of course, a well-balanced diet is also essential considering different foods contain different amounts of salt. This is the logic of a well-rounded diet. Combining foods from the different food groups helps to provide us with a balance of fats, sugars, protein, vitamins and minerals (salts).

In regards to health, some people canoot consume excessive amounts of salts (salts, meaning sodium chloride and potassium chloride). Older individuals, those with diabetes, hypertension, and kidney disease have an increased susceptibility to the blood-pressure "raising effects" of salts. This is because salt, as reviewed in our section on osmosis attracts water. Therefore, an increase in salt intake caused water to be retained in the blood. Therefore, blood volume increases and this results in higher blood pressure. Any individual with a disease process (eg., kidney disease) that affects the salt excretion in the urine can develop hypertension. Therefore, salt intake must be carefully regulated with clinical monitoring. There are also individuals with unusually low blood pressure. If this doesnt affect well-being, this blood pressure may be normal for that individual. However, if the low blood-pressure (hypotension) is affecting the health of the person in question, it can sometimes be recommended to add a bit of extra salt to the diet, hency, slightly raising their blood pressure. There is much debate on what's wrong and what's correct. We do know that hypertension is associated with increased risk of stroke and heart disease. This is because, as previously stated: Increased blood volume puts more pressure on the walls of the blood vessels. Logic tells us that if there is too much pressure on the blood vessel walls, there is a chance that they can rupture. If this occurs in the brain, it is referred to as a stroke. Additionally, a higher blook pressure and increased blood volume make it harder for the heart to pump. This is why heart disease can result from chronic hypertension.

The average individual should have in their diet a minimum of just over 4 and a half grams of potassium per day. This is includes potassium contained in foods and any added salt in the form of potassium chloride. Potassium helps to regulate blood pressure, aids in regulating the pH (acidity) of blood, nervous impulse conduction, hormone regulation (eg., aldosterone), as well as other functions.



Learn more water and ELECTROLYTES

Bhiochemistry of Water

Sodium

Chloride

Potassium

CSF