If you have high ionized calcium, but normal serum calcium, are you still considered hypercalcemic?
Blood tests usually measure total serum Ca and ionized Ca. Ionized Ca is just part of the total Ca that you have measured. Ca in your blood exist as ionized Ca (free Ca), and bound to proteins (like albumin) and organic molecules. You have an average of about 50% ionized, 40% protein bound, and 10% complexed with organic molecules. The % Ca that is ionized in your serum fluctuates with your blood pH. If your blood is more acidic, then less Ca can bind to proteins and organics, making your ionized Ca go up. Since your serum Ca is normal, you have normal levels of total Ca, so are not hypercalcemic. Another indicator is that if your Ca levels were high, your PTH levels would drop in response. Since your PTH is normal, then everything is fine. Unless your ionized Ca is sky high, I wouldn’t worry about it.
