Skip to content For most adults, the recommended daily intake is around **600 IU (15 mcg)**, increasing to **800 IU (20 mcg)** for adults over 70. The usual tolerable upper intake level for adults is **4,000 IU (100 mcg) per day**. Higher doses may sometimes be prescribed to treat vitamin D deficiency, but they should generally be taken under medical supervision. People should also remember that vitamin D may be present in multivitamins, calcium supplements, fortified foods, and other products
