Vitamin D Safe Upper Limit
The Safe Upper Limit is set by the US Institute of Medicine. It is the maximum daily dose that the IOM believes is safe for almost everyone to take every day.
The current Vitamin D Safe Upper Limit from the Institute of Medicine is 4000 IU for an adult.
For thirteen years – until November 2010 – it was 2000 IU. Now it has been doubled. Why?
Because in 15 minutes on the beach, an average fair-skinned adult can make at least 10,000 IU of vitamin D. (Dark-skinned people take longer, but make the same amount in the end.)
In fact, many people can make 20,000 IU of vitamin D in a single sunny session, five times as much as the IOM’s limit.
But has nature made a mistake, allowing us to make all that vitamin D? It appears not.
The New Safe Upper Limit – Still Too Low
There is no record of anyone, anywhere, ever becoming vitamin D toxic from sunshine alone. So we can be pretty sure that even 20,000 IU of vitamin D3 daily is not toxic for a healthy adult.
In fact there has never been a case of vitamin D toxicity at anything less than 30,000 IUs of vitamin D daily.
In the light of modern research, widespread vitamin D deficiency and epidemic levels of vitamin D-related diseases, an upper limit for vitamin D of just 4000 IU is still much too low.
- It does not allow people who are seriously vitamin D deficient to quickly restore their vitamin D levels to healthy levels.
- Some people cannot maintain even an adequate vitamin D blood level (35 ng/ml) on 4000 IU per day
Vitamin D, toxicity only occurs when a very large accumulation of the vitamin has been taken into the body (usually millions of International Units), in excess of the body’s requirement. (This usually happens over a long period of time.)
Up to that point, even very high daily doses of vitamin D3 (e.g. 50,000 IU) carry little risk for people in good health, even though repeated daily for several weeks. (But this is not a dosage recommendation!)
If you are uncomfortable about taking the higher doses of vitamin D required to reach optimum vitamin D levels, then you may be reassured by the IOM’s Safe Upper Limit.
After all, if the IOM thinks you will be quite safe taking 4000 IU of vitamin D per day, you can be pretty sure it’s O.K!
But even 4000 IU may not be the right dose for you, if you are aiming for optimum vitamin D. It could be too high, and it could be too low, depending on your own Personal Vitamin D Dosage.
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