Is 10,000 IU of vitamin D safe?

Safety of High Doses of Vitamin D

While the generally accepted safe upper limit for vitamin D intake is 4,000 IU per day, recent studies indicate that doses up to 10,000 IU per day do not appear to be linked to toxicity. It is worth noting that most reported cases of vitamin D toxicity are typically due to dosing errors, resulting in the consumption of much larger amounts than intended.