Purity Products - How Does Vitamin D Work?

[Naturyl]

According to some research, the body needs at least 50 ng/ml of 25-hydroxy D to have any appreciable levels circulating in the blood and getting into the cells (and therefore the genes). At levels less than 50 ng/ml, the activated D is apparently stored exclusively in the liver. This is one reason testing is important. Personally (while I am not a doctor), I would recommend aiming for levels of 60-80 ng/ml, based on the research I have seen.