Kendall: There are companies that do vitamin deficiency tests but in my opinion, I would spend your money on a good supplement instead. Unless you are doing the fat soluble vitamins like Vit A, D or E, other vitmins like the Bs are constantly changing in your body because they are water-based.So, if you had your vitamin def test done on Monday, and it showed deficiencies of say B6, it could change in a matter of days depending on what you have eaten. Do you see, what I am saying?? If you suffer from fatigue, you should have a B12 test and your insurance would cover that. D