In fact, there is a spot for a few of the lower-dose vitamin D dietary supplements you see on the market (suppose something lower than 3,000 IU)—particularly when somebody is taking a number of dietary supplements that include vitamin D3, like a multivitamin and a bone or immune well being complement, highlights dietitian Jess Cording, M.S., R.D., CDN.* A lower-dose product may also be a simple method to increase your present D routine within the winter months, she suggests.