Vitamin D deficiency is widely overestimated, doctors warn
Doctors are warning about vitamin D again, and it's not the “we need more” news.
Instead, they say there's too much needless testing and too many people taking too many pills for a problem that few have.
The nutrient is crucial for strong bones and may play a role in other health conditions, though that is far less certain. Misunderstandings about the recommended amount of vitamin D have led to misinterpretation of blood tests and many people thinking they need more than they really do, some experts who helped set the levels write in Thursday's New England Journal of Medicine.
Correctly interpreted, less than 6 percent of Americans ages 1 to 70 are deficient and only 13 percent are in danger of not getting enough.
That's concerning, “but these levels of deficiency do not constitute a pandemic,” the authors write.
Yet people may think there is one.
Blood tests for vitamin D levels — not advised unless a problem such as bone loss is suspected — are soaring. Under Medicare, there was an 83-fold increase from 2000 to 2010, to 8.7 million tests last year, at $40 apiece. It's Medicare's fifth most common test, just after cholesterol levels and ahead of blood sugar, urinary tract infections and prostate cancer screening.
“I'm not sure when it got popular to check everybody for vitamin D deficiency,” but patients often ask for it, especially baby boomers, said Dr. Kenny Lin, a Georgetown University family physician and preventive medicine expert.
Vitamin D pill use also grew, from 5 percent of Americans in 1999 to 19 percent in 2012.
That may be due to many reports suggesting harm from too little of “the sunshine vitamin,” called that because our skin makes vitamin D from sun exposure. It's tough to get enough in winter or from dietary sources such as milk and oily fish, though many foods and drinks are fortified with vitamin D. Labels soon will have to carry that information.