Vitamin tests can be tricky since I had a unique vitamin analysis test, which could detect which vitamins my body was not absorbing. I think regular blood tests only show the level in your blood at the time, but not if your body is actually absorbing it. This unique test result showed I wasn't absorbing vitamin A (not that I was low, but that I wasn't absorbing it). I took a regular blood test for vitamin A shortly after this test. It did not show a deficiency...probably because it was in my blood from eating lots of vitamin A in my diet. I could tell the specialized test was accurate because everything that I was deficient in regular blood tests like vitamin D, zinc, etc, still showed up as lower levels, but my body was still absorbing it unlike vitamin A.