Harvard Health Letter

By the way, doctor: Is that too much vitamin D?

Q. My doctor found that my blood levels of vitamin D were low, and gave me a prescription for 50,000 international units of vitamin D to be taken every two weeks. But I've read that the recommended dose is more like 1,000 IU a day, and that more than 2,000 IU a day is unsafe. I'm a healthy woman (albeit somewhat osteopenic already) and don't want to do more harm than good!

A. Your doctor's prescription makes sense, but I can see why you're confused.

When people are discovered to have low levels of vitamin D, it's often recommended that they "tank up" on large amounts for several weeks and then go to a daily dose of 1,000 international units (IU). Don't worry: daily doses well over the usual 2,000 IU upper limit won't overload you and cause toxicity because your body's stores of the vitamin are very low. I usually start my vitamin D–deficient patients on 50,000 IU pills, one each week for several weeks.

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