For example, evidence is accumulating that dairy food consumption may reduce hypertension and risk of certain cancers. Regarding the question of equivalence of dairy foods to build bone strength, the nutritional composition of dairy products differs greatly. The Food Guide Pyramid recommended serving sizes are based on calcium equivalents. In reality the equivalence is more complex. For bone strength one must take into account not only the calcium content of the dairy product but also the protein, sodium and potassium.
Dietary protein is related to calcium excretion.
High protein intake is associated with greater loss of calcium in the urine. Cottage cheese 5 Dietary sodium intake increases urinary calcium loss because of sodium-calcium exchange in the kidney. One gram of sodium intake is associated with approximately 20-40 mg of calcium loss. The calcium to sodium ratios in dairy products vary widely. Two servings of dairy products as skim milk would provide 352 mg of sodium, while two servings of dairy products taken as processed cheese would provide 1,624 mg of sodium.