I plan to get my Vitamin D & B-12 levels checked soon. They were last checked 20 months ago, and I have been taking oral Vit D & sublingual B-12 pretty regularly ever since. I recall that I need to stop taking these supplements at some point prior to getting tested so that the test results will reflect the actual level in my body, not the amount I just deposited into my bloodstream that morning from a supplement. Is that true? If so, how long do I need to go without Vit D and B-12 for my blood test to be accurate? A day? A week?