Vitamin D3 is the important one. Don't let people tell you it has to be a certain, organic kind. My doctor told me to just pick up a bottle at walmart. I bought the cheapest one I could fine, started taking it and my levels within 6 months were normal. I took 6000 units a day for six months. Now I take 4000 units a day and that keeps me in a good health level range. Not everybody is deficient, so before you start taking it, please get checked. To much, which results in to high of a level, can be just as harmful to your body in a different way then being to low.