Some Vitamin D Tests Flawed

I've been telling you over and over that you probably need more vitamin D than you've been getting. See Everybody Needs More Vitamin D for an example with links to earlier postings.

Scientific studies have "reported that low levels of the vitamin may be linked to medical conditions including certain cancers, diabetes and immune system problems," which has lead many concerned people to get their levels of vitamin D tested, up some 80% over the last year at one laboratory.

A good thing, right? Sure. Unless that laboratory's tests turn out to be faulty, giving levels of vitamin D sometimes too high and sometimes too low.

That's a huge problem recently discovered in numerous tests conducted by national testing giant Qwest Diagnostics, of Madison, N.J.

Mary Brophy Marcus reported on this for USA Today. The problem with the problem is that we have no idea of the scope of the problem.

Testing problems were linked to a small percentage of the company's labs, says Wendy Bost, a spokeswoman for Quest. The company is not making public the locations where the mistakes occurred or saying how many patients may have been affected. However, the pathology publication The Dark Report, who's [sic] current issue drew attention to the Quest case, suggests thousands of patients may have been impacted.

The inaccurate tests typically gave readings that were too high — meaning some patients who need vitamin D supplementation might not have received it — but not in all cases...

While not getting needed supplement can be a long term concern, getting too much when it's not necessary can be dangerous in extremely high doses. Fortunately, the dangerous level is around 10,000 IUs a day, while even the largest doses normally given are 1000 IU or lower.

What to do now?

[Joan Lappe, professor of nursing and medicine at Creighton University in Omaha, Nebraska, who has conducted research in vitamin D] says concerned patients who are taking the vitamin should see their physicians and get double-checked. "If you stop taking it for a couple days or weeks it's OK and probably not going to make that much of a difference for most people," Lappe says. Though she says kids should be evaluated more carefully.