More and more evidence is coming out in favor of higher doses of vitamin D than current recommendations.
In a recent blog, I talked about how vitamin D reduces your risk of cancer. I also talked about how numerous people are vitamin D-deficient, particularly people at northern latitudes like our Seattle area.
Another thing I mentioned in the blog was how the current RDA (400 International Units, or IU) may be well below what many people need to maintain optimal blood levels of vitamin D. I also said how higher doses, like 800 or 1000 IU, may not be enough.
Well, a study was just published in the American Journal of Clinical Nutrition suggesting we may need A LOT more vitamin D than any of us think.
In this study, the researchers took 138 subjects and gave them vitamin D for 6 months. Every 2 months, they adjusted the dose, trying to find the right dose to keep blood levels at an optimal level.
The researchers found that people needed 3800 - 5000 IU per day, to maintain optimal concentrations! This is 10 times the RDA!
It's obvious that people need to be getting a lot more vitamin D then what they're getting. It's also obvious that the current RDA is waaaaayyyy too low. Unfortunately, the current "official" upper limit for vitamin D intake is 2000 IU, which was established back in 1997. But, as I mentioned in my previous vitamin D blog, a lot of scientists are thinking now that this upper limit is waaaayyyyy too conservative, and should be put at 10,000 IU.
Unfortunately, science is often slow to change. The Food & Nutrition Board (FNB) sets all of these values, and they usually meet every 10 years to set new ones. That would mean they should have begun their meetings in 2007, but I don't know if they did or not.
In the mean time, I know I'm going to be upping my personal vitamin D dose from my current dose of 1,000 IU to 2,000 IU or higher. Yes, that's above the "official" UL, but I trust the newer data that indicates the official UL is too conservative. With the way our winter, err, I mean our summer has been around here lately, it's obvious I won't be getting any D from the sun any time soon :)