Corrected Calcium vs. Ionized Calcium

Some calcium in the blood is bound to proteins (mainly albumin, which is why we do albumin correction) and some is free/ionized. Ionized Ca is the type of Ca that is immediately available to your body for nerves, muscles, heart function, etc. The bound Ca is more like a reservoir — it helps keep levels stable and can be made available but isn't immediately available.

You can think about it this way: total Ca is like all the money you have. Bound Ca is what you have in the bank and ionized Ca is the cash you have in your pocket — available to spend immediately.

In general, you'd feel better with normal ionized and low total than with normal total and low ionized. However, keep in mind that:

1. Ionized Ca is a tricky test and results can be inaccurate if not handled properly. 2. Albumin correction isn't always accurate.

So, while corrected Ca or ionized Ca are better indicators of the amount of Ca available for your body and tend to correlate better with symptoms, it's helpful to take your total Ca into consideration, too.

For example, if your total is low and your ionized is OK, but you're symptomatic — you might want to increase your dose. Personally, I like to look at total, corrected, and symptoms all together.