Hi Shell, I have the opposite-high B-12 (3-4x normal), but I have other low vitamin levels. Some doctors believe that the hormone imbalance caused by the tumor affects the way our bodies absorb vitamins and nutrients. This could explain why we have low and high levels of vitamins. I have severe vitamin D deficiency (osteomalacia) and took 1200mg/daily replacement for a month and my next test showed my vitamin D level was even lower than before! I now take 2,000mg/daily. There is no explanation for my lower levels other than my body not being able to absorb the vitamin. I will see what my level is now in a few weeks-I am not expecting it to be much higher. I also have high calcium, even though I avoid any extra calcium. This is probably due to my parathyroid gland. I have several other high levels of vitamins-so high that my nutritionist recommended that I stop all vitamins and supplements and avoid high levels in different foods. I have to check vitamin content in everything now and avoid anything with high levels-it's crazy. My body is not absorbing and using the vitamins the way it should. I chalk it up to hormonal imbalance. You definitely need B-12 replacement to feel better. I have noticed a huge difference with my vitamin D replacement-I have a lot less aches and pains. I definitely notice when I miss taking it (usually because I am sick and can't keep anything down), I have severe aches and pains in my bones, muscles, and joints. If I take the vitamin D, my pain will go away within an hour. It's amazing. I have had this deficiency for years (I also have vertebre compression and loss of height), but it was only caught this summer. I have been feeling much better on the replacements. I hope you feel better on the replacement, soon. It should help with fatigue and lack of energy, as well. Take care. You're in my prayers. Meri | 