I know this is anecdotal but here it goes anyway. I've had bariatric surgery and as such my physician orders a full blood panel once a year. I had a significant

I know this is anecdotal but here it goes anyway. I've had bariatric surgery and as such my physician orders a full blood panel once a year. I had a significant deficiency in vitamin D, B12 and Iron. After taking supplements for 3 months they all returned close to recommended levels. One difference may be the specific bio availability of the supplements I take. The Vitamin D is D3 (it is an oil filled gelcap) which increases your body's ability to absorb it. The powdered Vitamin D is supposedly worthless. I take 50,000 IU twice a week, most pills you buy from the store are 250 to 1000 IU, although you can find 5,000 IU. The B12 is a sublingual tablet which increases bioavailability, but unsure how much better it is supposed to be compared to what you'd normally find in a multi vitamin. Lastly, the Iron supplement - Feosol with Bifera has two kinds of iron (HIP and PIC) which minimizes side effects and increases bio availability. I started taking bifera before the other two and the increase in my energy levels after a week or two was really quite remarkable. As other people have stated, this is something you should probably talk with your doctor about, but try to be as informed as possible when you do.