On November 30, 2010, a panel of experts from the U.S. Institute of Medicine (IOM) recommended that all Americans take more vitamin D, updating its 1997 reference values.
For people aged one to 69, the new Recommended Dietary Allowance (RDA) is now 600 IU of vitamin D per day, up from 200 IU per day for those under age 50, and up from 400 IU for those aged 50 to 70. For those aged 70 or more, the RDA is now 800 IU of vitamin D per day, up from 600 IU. For everyone nine years of age or older, IOM set the Tolerable Upper Intake Limit for vitamin D at 4,000 IU per day.
While many recent studies suggest the need for even higher levels of vitamin D, and that vitamin D is safe, IOM clearly recognizes that more vitamin D is necessary to maintain health.