There are two vitamin D metabolites that are tested as part of the Marshall Protocol:
The Knowledge Base articles devoted to those tests offer recommendations for how frequently and under what circumstances these metabolites should be tested. Note that some physicians omit testing 1,25-D.
It is not necessary to fast for these blood tests. The D Metabolites tests can be done whether or not the patient has been avoiding ingested vitamin D or sun/lights. This information is taken into consideration when interpreting the test results.
Contextual interpretation of a patient's 25-D and 1,25-D results are available using the vitamin D metabolite calculator.
Given the recent interest in vitamin D metabolism and its role in chronic disease, most Marshall Protocol patients do not have trouble convincing their insurance company to cover the cost of the test.
However, those patients who have been told that the test is not justified, have pointed out:
The test for 25-D is done routinely at many labs and does not require special handling.
When the 1,25-D test is drawn at the same time, the same blood specimen is probably used for both tests and they can both be frozen. Freezing preserves the specimen and will not harm it even if it isn't necessary.
There is an at-home 25-D test kit available for routine testing.
The 1,25-D assay is very sensitive and if it is not sent to the performing lab frozen, it will not be accurate. The sample must frozen to prevent dedegration leading to an inaccurate, lower result. Patients may want to verify that the technician at the drawing (satellite) lab plans to freeze the sample for shipping (see sample Doctor's instructions below). There are two Quest codes for 1,25-D and the order must specify Test Code #4729X to be frozen.
Note: Some Quest drawing labs have inaccurate information in their printed manuals. There has been no change in the need to freeze the 1,25-D sample for transport.
I don't know if it will do any good but the local Quest lab said if the 1,25-D has code #4729 it will be frozen, at least at the draw facility.
I learned this when investigating for my wife. Her first test was mid 30's but was coded wrong. Second test after my discussion with the lab was frozen and returned 64 pg/ml. Big difference!
To facilitate correct handling of the blood sample for 1,25-D and to avoid having to tell the drawing lab how to do their job, patients can ask their doctor to sign and staple the following instructions to the lab order:
- Please perform the following Vitamin D tests: 1,25-D and 25-D.
- Please ensure that collection staff arrange for centrifuging and freezing of the 1,25D sample. (only)
- The sample should be allowed to settle and clot at room temperature for at least 30 minutes (but no more than two hours) and then centrifuged. Do not hold on dry ice prior to centrifuging.
- After centrifuging, freeze at between -2 and -10 C.
- The sample must be transported on dry ice in order to remain frozen until it reaches the testing lab.
Note that 1,25D levels are exceedingly minute. 1 pg/ml is one millionth part of one millionth part (pico is 10 raised to the -12 power) and the pathology to measure such levels is extremely sensitive to correct handling. For every gm of Vitamin D taken in barely one part in 1,000 ends up as the double hydroxylated 1,25-D.
The best disease codes for 1,25-D and 25-D testing are those for osteoporosis. All sarcoidosis patients, for example, are at risk for osteopenia or osteoporosis.
There have been no reports of insurance or Medicare refusing to pay for these tests when these codes are used:
CPT (Current Procedural Terminology) codes are as follows:
If at all possible, use Quest Diagnostics for your 1,25D test. Quest will not measure a sample which has been handled incorrectly.
Based on their track record for handling samples of 1,25-D, the American testing company, LabCorp, is not recommended. Their results have proven unreliable even even when the sample was shipped to them frozen, which may be due to a policy of allowing the frozen sample to thaw in the refrigerator before they run the test.
Given how mishandling invariably reduces the values of 1,25-D, only when the result of the 1,25-D is elevated, can one be sure that a Labcorp test was performed properly.
If LabCorp is used and a 1,25-D level is low, it is impossible to know if it's a lab error or a true result.
Patients have the option to order a home 25-D test kit directly from various labs.
The alleged instability of 1,25 vitamin D when not frozen appears not to be correct, according to this paper: http://www.clinchem.org/cgi/reprint/27/5/773