OK this page seems a bit fishy, they say that "When healthy, the pH of blood is 7.4, the pH of spinal fluid is 7.4, and the pH of saliva is 7.4. Thus the pH of saliva parallels the extra cellular fluid."
Then they say that some people have had thier saliva measured at pH 4.5. Does this mean that blood pH is 4.5?
Do you know the limits of blood pH, and what a pH of 4.5 means?
If saliva testing is the "most consistent and most definitive physical sign of the ionic calcium deficiency syndrome." Why would there be a need for a blood Ca test? Just test the saliva.
Read of few of the articles that are cited and see what they really say.