The current tolerable upper limit of vitamin D intake is 50 mcg (2, 000 IU) per day.

CNN: How much vitamin D should someone over 55 take?

The latest RDAs of vitamin D increased to 600 IU for adults up to the age of 70 and 800 IU for adults older than 70, and the tolerable upper limit increased from 2, 000 to 4, 000 IU per day for adults.

CNN: How much vitamin D do I need?