Are Vitamin D Megadoses Safe?

I’ve seen a lot of ridiculous claims about how safe and essential vitamins can supposedly hurt you, but none are as bad as the Institute of Medicine’s official position on vitamin D.

The agency claims doses of 10,000 IU or more are dangerous.

Your body generates the equivalent of 10,000 IU in just 30 minutes of sun exposure, which should tell you how ridiculous that claim is. But in case the evidence from your own body isn’t clear as day, one study looked at doses of twice that level.

Researchers gave megadoses of 20,000 IU, once a week, to seniors in nursing homes (who are often badly deficient in vitamin D) and found the level to be perfectly safe.

Of course, most people don’t need megadoses (although they are essential for some, like seniors in care facilities). For otherwise healthy adults, I recommend between 2,000 IU and 5,000 IU per day. I like to monitor patient’s blood levels so they get the optimal dose.