I agree that testing is important. That is an obvious point.

But food typically does not have Vit D in it. The D in milk is D2 and less bio active. I00IU D2/8oz of milk.

I have seen some newer foods with labels D3, on them but they are few and far between.

Vit D is NOT a vitamin, and I wish with all the media attention this would be explained. Biologically we evolved to make our own from the SUN. But today the medical community has squashed that source...with all the suggestions about skin cancer, and coverups, and sunscreen products.

D2 and D3 are very different chemically. And react differently in our bodies. It is incredibly naive to put out a government statement with such low values as a recommendation.

You know I had a patient once who took SIX 50,000 IU daily, and had been doing so for years. I ran into him at an HMO and when I saw his use, I went to the supervisor (I was temping there until they could hire a new person)...and she said he had been getting that for several years, and not to verify it or do anything but just take care of it! This was an older gentleman. Details were not forthcoming either from her.
I will never forget it! But that was before we had the newer research we have now. That RX D2 was not serving him well!