In reading one of the 2 articles linked by Silver, I spotted the following excerpt.
In November a panel of the Institute of Medicine concluded that having a blood test for vitamin D is pointless: almost everyone has enough D for bone health (20 nanograms per milliliter) without taking supplements or calcium pills. Cost of vitamin D: $425 million per year.
I would like to relate this story. The wife of one of my brother-in-laws was sick for a while. She had a few problems that her doctor could diagnose, but overall she complained of feeling really lousy. It was perplexing to her doctor, who ordered a bunch of tests and just could not find out why. Finally, they discovered that, you guess it, vitamin D deficiency.
Good grief! Vitamin D deficiency in the SW, where the sun shines nearly 99% of the year!
It is generally accepted that unless one is in the Artic, a few minutes of exposure a day would be sufficient for the body to generate enough vitamin D one needs with the help of the sunlight. Obviously, my BIL's wife has been avoiding the sun and must be rushing from her home to the car and to her workplace without having much outdoor activity at all.
As she has good health insurance from her work, it did not cost her too much money, but of course she suffered for a long time before she could get properly diagnosed. I don't blame her doctor for not seeing the problem right away; how one could have known some people are as afraid of sunlight as Dracula?
The moral of the story: A bit of medical knowledge by the patient can help him getting cured faster, as well as keeping the care cost low.