First, we're not experts on here, just folks like you. We have experiences that bring us to this forum, but not true expertise. Second, blood tests vary a lot if you take more than one of them because levels in our bodies vary depending on what we ate that week, the time of day you get tested, the time of month, etc. So the results of nutrients should vary. Also, the forms of supplements doctors use aren't always the best -- in fact, they tend to be the worst for absorption. Your D3 was way too high a dose, so I hope your doctor isn't going to keep you on that. The best way to get D is to go out in the sun at peak hours for a half hour, but most of us don't do that anymore as our lives have moved indoors for various reasons including work and the irrational fear of skin cancer, which has been way oversold. As for B12, some forms are absorbed well and some aren't, and so it's more important you get the right form than the dosage. The reason your doctor altered your B supplement is puzzling, because over time a good B complex should accomplish the same thing as what he changed you to, which is something called a homocysteine control formula that is designed to protect from a suspected factor in causing heart disease. But the good thing about that second B formula is it accounts for the balance required for B12, B6, and folate -- levels of each can affect levels of the other. But homocysteine formulas aren't sublingual, and if you want quick B12 in your system you either take it that way or by injection. What you want, and what your doctors are aiming for, is a permanent change so your levels stay in a good range, which will depend ultimately on your diet unless they find you have something going on in your physiology that is preventing you from absorbing them. As for the iron, again, maybe you ate foods high in iron that week. I would bet that if you got tested every week for a year you'd see some significant variation. But if it's a disease state that is affecting your blood cells, there are two types of anemia -- iron deficiency and B12 deficiency. They can go together. Hopefully, your doctors are specialists who will get this straightened out, but don't expect nutrient deficiencies to go away overnight. If they rule out some problem your body is having absorbing these nutrients, then it might benefit you to see a holistic nutritionist and learn how to eat better. Good luck.