Most regular readers of this blog have probably already gotten their Vitamin D levels checked (blood test). I have mine checked every 6 months with Dr. Carr, and despite the fact that I faithfully down my 5000 IUs of Vitamin D3 every morning, getting to an optimal level has been a struggle. Dr. Carr explained it to me that the enzymes in our skin that convert sunshine to Vitamin D become less efficient as we age, so that sun exposure does not guarantee a good Vitamin D level (which is kind of ironic------I'm nice and tan from being out in the pool working out this summer!)
New blood test on the horizon to test the different types of Vitamin D, it will more accurately pinpoint deficiencies and provide important clues for research into Vitamin D and disease process. Read about this new test in this article from News-Medical.net.