The correct test is called a 25-hydroxy vitamin D level, and this is actually the stored form of the vitamin D. The 1,25-hydroxy vitamin D is the active form, and that one almost always stays normal while the stored form, the 25-hydroxy vitamin D, is the one that varies depending on intake. And she should get this; it’s a regular blood test that her regular doctor or whatever type of providers she has, can measure for her.
The results usually come back in nanograms per deciliters--ng/dl--and we think the optimal level of her vitamin D, 25-hydroxy vitamin D is above 30. It’s probably somewhere between 30 and 50, and about 80% of the people in United States are below 30, and certainly below 20 is very severely deficient. Below 10 is even more severe, but we are getting a pretty good indication that a value below 30 is really less than optimal, and somewhere up to probably 50 or 60 is probably a reasonable value on the upper range. There’s a slight suggestion that maybe too high levels might be bad for you, but I think most people say that, you know, just as long as you get it above 30 is reasonable. People with cancer, especially breast cancer, they even suggested they should be a little bit higher, maybe optimal will be about 50.
And I have also heard that people that are overweight need to take a little bit more because the vitamin D easily stores in their fat and then gets lost in their system. So let’s actually take this away from the results, and let’s do the daily prevention because what leads the result is the supplementation on a daily basis. So what should women know?
Dr. Theodore Friedman:
Okay, so it’s very confusing here because the recommended daily allowance set by the government is only 400 international units of vitamin D a day. This is a very low dose and is really not enough to keep your levels even up to maintenance, let alone try to replace it.