What may cause a Combination of low calcium and low total protein and low globulin on a blood test?

Answer 1

Low globulin can be due to immune deficiency associated with decreased antibody production. This would also account for lower total protein (because globulin is a protein), however it would not account for the low calcium level. Calcium is bound to protein in the blood, so low protein can be associated with a spruriously low calcium (i.e. a calcium number that is low without actual calcium deficiency). This may be the case if the albumin (another protein) is low, and there is a formula to correct calcium for low albumin, where:

Corrected Calcium = (0.8 * (Normal Albumin - Pt's Albumin)) + Serum Ca

Alternatively, an ionized calcium level can be checked and will be normal if the serum calcium was only low due to low albumin.

Without knowing the clinical context (which would be very helpful), the most likely single explanation for low globulin, low total protein, and low serum calcium is protein nutritional deficiency. In this case, the body is overall protein deficient and so it is not uncommon to find a decrease in all protein levels (especially if severe). In this case, the low serum calcium is due to low albumin, as above. This can be further explored by checking a pre-albumin level (typically low if protein deficiency due to poor diet).

You should talk to the physician who orderd the tests for a better answer, as only he or she knows why the tests were ordered and can interpret them in the appropriate clinical context.