Calcium is measured to evaluate function and adequacy of a physiologic processes. Calcium plays a critical role in several body functions such as, coagulation pathways, bone health, nerve conduction, and other functions. It is important whenever you are evaluating laboratory results that you look at the whole picture of the person, including medications, other laboratory studies and health history. One value is not a stand alone result. There are many factors that effect calcium results.

Factors that effect calcium results: (not an all inclusive list)

pH

Albumin

Lactate

Heparin

Vitamin D deficiency

Magnesium depletion

Anticonvulsants

Renal Disease

Pancreatitis

Parathyroid

Thyroid

The two most common issues following Weight loss Surgery or Duodenal Switch may be albumin level and Vitamin D level. Please see past blogs on Vitamin D. Magnesium may also play a role in a Duodenal Switch patient.

The most common calcium result drawn is the total calcium level. Laboratory results may not explicitly label it as such, however, it measures the calcium that is bound to protein. Ionized calcium is the free calcium that is representative of the true total calcium. Ionized Calcium can be measured by ordering specific lab. Alternatively, the Ionized calcium can be calculated by the following formula: Corrected calcium mg/dL = (0.8 * (Normal Albumin – Pt’s Albumin)) + Serum Ca ) or use the calculator at the bottom of this post.