The only way to be certain that you do not have a Vitamin D deficiency is to test for 25-hydroxy Vitamin D level. This is a blood test. The test measures 25-hydroxy Vitamin D2, 25-hydroxy Vitamin D3, and Total 25-hydroxy Vitamin D. This test is not yet part of routine blood testing for everyone. It should be done more often.
We have learned that daily vitamin D needs and optimal levels for vitamin D are much higher than we previously thought.
Testing for 25-hydroxy Vitamin D level is a basic part of any bone health or Osteoporosis evaluation. Vitamin D Deficiency is the most common contributing factor to Osteoporosis. Fortunately, Vitamin D Deficiency is the contributing factor to Osteoporosis that is most easily treated and prevented from returning.
If you have not ever been tested for 25-hydroxy Vitamin D level, ask your doctor to order this test at your next check-up.
Jay Ginther, MD
2008 / Revised Feb 2011