Originally Posted by
NeedAGirl!
The point of low sodium diet is that we think we want sodium to be low in the fluid in the tubes and in the CM. Because sodium levels are so tightly regulated in the blood, if you are not eating much sodium, your body will draw sodium out of the other fluids in the body making them lower. For instance, the urine will have lower sodium. In the Dutch study, they also measured 24 hour excretion of sodium in the urine before and after the diet. Also, I believe that calcium probably sways. Excretion of calcium is tightly linked to sodium excretion. When you eat more sodium, your body needs to keep the blood levels within the normal range so excessive amounts are lost in the urine and it takes calcium with it.