Vitamin D Testing Problem

Just this morning, I read an Associated Press article stating that Quest Diagnostics, the nation's largest medical laboratory company, has had problems with some of its tests for vitamin D levels and reported levels higher than they actually were. Per Quest, doctors were notified and retests offered. The article states:

Major lab discloses problem with vitamin D testing
By RICARDO ALONSO-ZALDIVAR (Associated Press Writer)
From Associated Press
January 07, 2009 11:09 PM EST
WASHINGTON - The nation's largest medical lab company says it recently discovered and fixed a problem that led to inaccuracies in a small number of tests for vitamin D deficiency.

Quest Diagnostics of Madison, N.J., notified thousands of doctors in the fall who had ordered tests for their patients that it had found the problem and then offered free tests for patients whose results were deemed questionable, said Gary Samuels, the company's vice president for communications.

Blood tests to check levels of vitamin D are on the rise because of research showing a possible link between too little of the "sunshine vitamin" and a higher risk of cancer or heart disease.

People normally get vitamin D from exposure to the sun or from fortified milk, orange juice and cereals. It helps build strong bones. But recent research, which still is being debated, suggests it also may play a broader role in protecting against a number of diseases.

"Last year, we did have an issue in a few of our labs that affected a small minority of tests in those labs," Samuels said in an interview this week. "We identified the problem ourselves. We corrected the problem. We notified doctors and other customers and offered free retesting."

Quest, which reported more than $6 billion in sales last year, is the largest provider of medical laboratory tests in the U.S. The company has reported double-digit sales growth for its vitamin D tests in recent quarters. Quest collects medical samples from hospitals, doctors' offices and clinics for tests to diagnose medical conditions. It employs more than 43,000 people worldwide.

Dr. Wael Salameh, a senior medical official with Quest, said internal monitoring picked up hints of a problem during the summer - an "upward trend" in the vitamin D levels being registered by some of its tests.

"That tipped us off," Salameh said.

Eventually, the company flagged about 7 percent of vitamin D testing results from 2007-2008 as questionable, although it believes the problem was much smaller. Generally, the readings obtained on the questionable tests were higher than they should have been, Salameh said. In some cases, though, it was hard to discern a pattern.

Salameh said he doubted that patients would have suffered any harm from the problem. People with serious vitamin D deficiency have physical symptoms such as fractures that their doctors would have noticed. "A good doctor would question the test," Salameh said. "For the few vulnerable patients, other indicators would have flagged the situation to their physician."

Quest officials said the cause of the problem turned out to be the way some of the company's labs were mixing chemicals used in the tests. But the company also is using a new testing technology, which is the subject of sharp debate within the industry. Critics say the method tends to produce vitamin D readings that are higher than warranted.

Aetna, the insurer, said it was notified by Quest about the problem on Oct. 8.

"We did not, however, see any immediate health issues ... that would have required additional action or intervention on our part," spokeswoman Wendy Morphew said in a statement. "We have not received any significant member inquiries on this matter."

Quest Diagnostics web address is http://www.questdiagnostics.com/.

By nobonesaboutit
Posted January 9, 2009 at 2:02 am
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Ya don't say...
I'm in Cincinnati area, always use Quest. My Dr had me on 50,000 IU every week. I was told my levels were normal after starting it. Now I question it and doubt my Dr would have informed me of Quest's problem.
Thank you

By BoneLady
Posted January 9, 2009 at 11:42 am
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nobonesaboutit, I hope you weren't one of the ones whose test results were incorrect, but who knows? I read another article with even more info on this subject. It is longer, so I am providing the link:

http://www.nytimes.com/2009/01/08/business/08labtest.html?em

By zeta
Posted January 9, 2009 at 1:49 pm
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Thanks BoneLady for bringing this to our attention. Actually this problem with Quest has been going on unfortunately for quite a while. The newsletter for the Vitamin D Council, which BTW is free, and usually has somethhing interesting in it, even if one doesn't agree with everthing said, has been covering the Quest problem. Apparently, according to J Cannell of the Vitamin D Council, Quest was slow to remedy this. But my impression from what you have posted, as well as what Cannell says below, is that finally Quest is making the necessary changes to insure an accurate test. Let's hope so:

January 7, 2009

"The New York Times just posted their article about Quest Diagnostic Laboratory's recall of their vitamin D blood tests. To my knowledge, this is the biggest recall in the history of medicine. Like the influenza and autism stories, the Vitamin D Council newsletter was the first publication in the world to report the story (July newsletter ).

http://www.nytimes.com/2009/01/08/business/08labtest.html?emc=eta1

Here is the trade publication, The Dark Report, which wrote about the issue yesterday. I cannot get their report for free, so please do not email me, asking or complaining about the cost.

http://www.darkreport.com/landing-page/quest-diagnostics-inaccurate-vitamin -D-test-results.htm

It is important to note that I think Quest Diagnostics has fixed the main problem with their vitamin D testing. As far as I can tell, the problem was in their preparation of blood samples.

However, I cannot get Quest to fix their second problem, correlating their method with the method used in virtually all the major scientific studies of vitamin D, the DiaSorin RIA (I am a consultant for DiaSorin). When you read that levels of 50 ng/ml protect you from heart disease, that does not mean levels of 50 by Quest, rather levels of 50 by a method correlated with DiaSorin RIA.

So don't be afraid to use Quest, but, if you do use Quest, you must divide your 25(OH)D result by 1.3 to get an accurate 25-hudroxy-vitamin D [25(OH)D].

Thus, if Quest says your 25(OH)D is 40 ng/ml, divide 40 by 1.3 (40/1.3 = 30) to get a true reading of 30 ng/ml.

As a 25(OH)D level of 50 ng/ml is the minimum needed for good health, your Quest level must say 65 ng/ml or higher for optimum health (65/1.3 = 50). Thus, when you read that levels of 50 ng/ml protect you from breast cancer that would be levels of 65 ng/ml if you use Quest.

LabCorp is not affected by this recall and continues to have accurate vitamin D tests, correlated very well with DiaSorin RIA.

Remember, you can save yourself all this concern and some money by testing your vitamin D levels in the privacy of your home. ZRT is accurate, has correlated their test with Diasorin RIA, and only charges $65.00 if you order through the Vitamin D Council.

http://www.zrtlab.com/Page.aspx?nid=12&action=view&category=14&partner=Vita minD%20Council

Remember, you can save even more money by starting vitamin D supplements before getting your 25(OH)D tested. Most adults need 5,000 IU per day of vitamin D in the winter. Children need about 1,000 IU per every 25 pounds of body weight. However, many people will still be deficient at these doses so after taking the vitamin D for three months, get tested. Please read the page below before doing anything, including emailing me with a question already answered on the page below."

http://www.vitamindcouncil.org/health/deficiency/am-i-vitamin-d-deficient.s html

John Cannell

9100 San Gregorio Road

Atascadero, CA 93422

Vitamin D Council

zeta- hope this helps tell the story

By windblown
Posted January 9, 2009 at 4:34 pm
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Thanks to all for the info on vitamin D... I've used Quest many times during the period they've mentioned, but my 25(OH)D is always really low, so if they are falsely elevating the score my deficiency is worse than I thought.

By BoneLady
Posted January 12, 2009 at 10:59 am
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windblown, Perhaps you should divide your Quest 25(OH)D results by 1.3 to get standard 25(OH)D results, as explained in zeta's post, or have your next vitamin D test done by another lab company. I would also be interested in hearing from anyone who has been offered a re-test.

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