Vitamin D Tests in Error
Thursday January 8, 2009
The largest medical laboratory in the United States, Quest Diagnostics, has admitted that thousands of its vitamin D test results may be in error, giving results that are too high or possibly too low. This error could potentially mean that people who need to take vitamin D supplements are not taking them.
Vitamin D blood tests have become more popular over the last few years as research has tied vitamin D deficiencies to several chronic diseases such as osteoporosis and multiple sclerosis. Your body makes vitamin D after being exposed to sunlight and you can also get vitamin D from foods that are fortified with vitamin D such as milk and breakfast cereals. Vitamin D supplements are available too, just be sure to follow label directions. Vitamin D taken in massive amounts over a long time can lead to toxicity.
Comments
Vitamin D is proving to be the most underrated, misunderstood piece of the daily nutrition puzzle. Forgotten (or sunlight assumed) and now at the cutting edge of supplementation. Bottom line, we probably don’t get enough (especially D3), and most of us probably need to supplement our diets with a daily tablet dose.
If Quest is giving results that are lower than they actually are, doesn’t that mean that some people are taking supplements and they DON’T need them, not the other way around?
I agree with Delores. If the test results are low it could mean people are taking supplements when they should not. Given that too much vitamin D is toxic this is potentially very serious.
Since melanin blocks sunlight absorbtion and thus could impact vitamin D production in the summer or Southern regions I wonder how supplement needs are calculated anyway-it seems there could be a lot of variables.
Curt
Delores and Curt — you are both right. The tests could be artificially high or low according to the New York Times article. I will note that in my blog post.
Do not wait for your doctor to contact you. I would suggest that if you had a vitamin D test done within the last two years, contact your doctor to make sure that you’re not on the list of those who may have a skewed result. Another option would be to ask your doctor, or Quest directly, for a retest.
Bonnie Minsky MA, MPH, CNS, LDN
Okay, I’m trying not to panic. My Endocrinologist just did a test and said that I basically had “no vitamin D” in my system at all. She prescribed 50,000 IU (prescription strength) of Vit D a day (started this past Monday, Feb 9th) the test was done on January 26th. When I saw the results it said that my levels were at 28ng/ml ( I think that’s how they chart it) that doesn’t look bad. I’ve been taking the suppliment for a week, but I’m concerned. She isn’t going to see me again until 6 weeks from now. Should I stop taking this? Please help me. I’m not sure what to make of all this!!