Only a small amount of the total calcium, called ionised or free calcium, measured in the blood, is active in body tissues. Generally, total calcium is a good indicator of the level of ionised or free calcium in the body, but there are exceptions.
Low albumin levels in the blood can reduce total calcium levels, but free calcium levels remain unaffected. However, you can calculate the albumin-adjusted calcium levels to give a more accurate result of free calcium.
In some cases, directly measuring the proportion of free calcium at the body’s normal pH is necessary due to the changes in the presence of calcium-binding agents like lactates or the changes in blood pH. This measurement is known as adjusted ionised calcium (at the pH of 7.4).
The interpretation of albumin-adjusted total calcium and adjusted ionised calcium levels (at 7.4 pH) is the same as total calcium levels.
You can undergo an adjusted calcium test at Private Blood Tests London. Visit us at Suite E, 117a Harley St, Marylebone, London W1G 6AT or call 02071830244 for your adjusted calcium test.