Today we're presenting yet another set of vitamin D information from a different research point of view - enzymology. I had the pleasure this last week to talk with Dr. Reinhold Vieth, a member of our scientists panel, about bolus dosing with vitamin D. A specialty of his is the action of the enzymes. We recorded this interview, along with a few summary slides, to share his thoughts with you. I am frequently struck by how much is known about various pieces of vitamin D, and the depth of a researcher's knowledge. Dr. Vieth is one of those experts who has worked in many areas in the field and has extensive knowledge. His perspective on the recent study, done by very qualified scientists, which used large monthly doses and resulted in an increase in falls was "I would have predicted that they would have problems." Dr. Robert Heaney, our Research Director, likened the bolus dosing to thyroid medication. He said, "People on thyroid medicine generally take it daily. If they took it all in one dose, once a month, we would predict that they would be sick!"  I also spoke with Dr. Holick and he indicated that he gives 50,000 IU every 2 weeks to his patients and at that interval and dose, has not run into any problems.

So, my question: How do we get the messages of the science to practice not only in our daily lives, but also in the design of new trials? For example, giving bolus doses of 60,000 IU at monthly intervals is not effective, and has been shown to create problems. This was certainly expected by Drs. Vieth and Heaney. How can we make sure that no more trials are done at this level or at this interval? It is not a physiological dose. Just imagine getting enough sun exposure in ONE DAY to get that. Well, first of all, your body's system turns off the production of D from the skin after about 20,000 IU in a day's exposure. It knows better.

I hope you will listen to Dr. Vieth's interview and think again about dosing intervals and how they can make a big difference in our system's response.

We will continue to provide you some significant ways of looking at vitamin D research and what is found that is beyond the immediate news headlines. Please continue to spread the word about the fact that keeping a steady intake on a reasonably short time scale is important.  Dosing intervals matter.

Onwards!