Jini Says: Many people with chronic illness are deficient in vitamin D and it needs to be taken in natural D3 form. The amount you need depends on your skin color and how much sun you get on your skin. We live in a rainy climate and I am half Indian, so I take 6,000 IU per day. My hubby is white so he takes 4,000 IU per day. We give our kids 2,000 IU per day.