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.