Interviewer: You talked about this in a book, you talked about the 2000 unit of tablets that we can get, some of the multivitamins that have less 400 or something like that. How do we know how many units that we should be getting that on a daily or weekly basis and you said earlier that depends on size too or so. Is it important just to get tested and go that rounds to try to-do ourselves at home?
Dr. Dowd: Well, there is two different ways you can go about this. You can test and then sort of hit miss, take a dose, re-measure, not enough take more, re-measure, too much, back off, re-measure, okay? There's a table in the book that is a weight dose, it's actually based on mycoholic data. So mycoholic and Robert Hiene, they did a study back in around 2004with a tip middle aged guys and they put one group on non, one group on a thousand, one group on 5,000, one group of10,000 units of vitamins D then followed on six months. Just to see what would happen to the vitamin D levels. That data gave us the affirm between that and the submarine data we have. We know exactly how this drug functions, vitamin D function as a pharmacokinetics stuff. Okay, and so we know, you can take that data, rejuvenate and put it in a table form, okay, the vitamin D level is 20and I want it to be 50 and you need to take this milliunits a day and you can take the data off the table, out of the graphics and put it into tabular form, and it works like a charm. And that table is in my book to exactly, precisely place your vitamin D levels. Okay, after that, if you want a rule of thumb to discern. Okay, I went to the doctor and measured level. I don't want to wait for two weeks to find out what my level is, I want to do something today. Mediographication part right? So there are rules of thumb that help you get started and then you can adjust it based on your blood level. The rule of thumb is for fair skin people. European-Americans, 20 units per pound is a raft estimate of what it takes to get average vitamin D levels in this country to where we wanted it tube. So you take CDC data, center for disease control says the average American, Caucasian-American, has a vitamin D level of 27 or something like that, 25 or27. And if we want it to be 50 to get from 25 to 50, requires about 20 units per pound. And then you can do the same math for African-Americans, darker skin, and there's gradation in between. African-American average vitamin D levels are like 15, 17, so you can get from there to 50. And so can take a long more to make that jump and as close as 25 or 30 units pound per day. Okay, these are the rules of thumb that I wanted it for myself because I was measuring levels inpatients, and see how much would me like to start taking? I don't know, I don't know until your blood levels comes low, so I can't take any until you get my level back or once I going to be. So, there's more phone calls and hassle. This way I can say, here's the rule of thumb, I start on this amount based on your size, and then we'll adjust it according to the blood level. And if I over shoot I back off, and if I under shoot I jack them up a little bit more.
Interviewer: You're talking about over shooting, you talk about that study that went from 1000 a day to 10,000 a day per person. Can you get too much and how do we know if we have too much of some of the risk factors or the warning signs?
Dr. Dowd: So the question of safety always comes up because it's a fat soluble vitamin and particularly people who are familiar with supplements if it's a fat soluble or a water soluble. If it's a water soluble, take anyone you want. If it's a fat soluble, you should be careful because it might accumulate in my system or in my fat stores. So we know the half-life of vitamin D is 10 weeks, so that's how slow it is as opposed to vitamin C which in the order of hours and it's gone, okay. So, 10 weeks versus a couple of hours, that is a big difference and you can't clear that 10 weeks very quickly if you over shoot. The beauty though if you go out to the sun to make Vitamin D, 10 minutes in the middle of the summer in the middle of the day, in your bathing suit and you're out of the lake party or something. You're making probably10, 000 units of vitamin D every five or 10 minutes and you're out all day in the party. Oh my god, you should be toxic right? But you're not. Mother Nature figured out a way to prevent that from happening at least with sun exposure so you can get sun burn and all that sun toxicity but not vitamin D toxicity. You measure your level and your level is okay because any additional vitamin D level beyond about 60, its waffle, it's somewhere between 60 and 90. The system in your body started to shut off production despite sunlight, so more sun comes in, converts stuff, and immediately system starts kicking inactivate this stiff you just create because it says, we got enough, we don't need it anymore so it starts to, its auto regulating sun exposure and vitamin D production. But supplementation is not, now if I go out, let's say I'm taking vitamin D supplement and my level is 50 where I wanted it to be, and then I go to a beach party. I'm going to overdose in the sun because my levels are already 50, no you won't because your skin will detect that your levels are already 50 and most of the D that you make will be inactivated at the party. And your level might go up to 80, but it is still stay probably into 1 hundred. Normally being roughly to 100, milligrams per meal but toxicity is the question is okay, the sun is self-regulating so how much do you have to take to push your levels outside of that 100. To get about a hundred, you probably have to take twice of what I'm recommending as a target dose, these 20 to 20 units per pound, or 20 to 25 units or so. We're working at 50 plus units per pound. These are a lot of vitamin D, okay. Not just to get you over a hundred but how many cases of toxicity are found over a hundred, almost none. In fact, how high you have to go before you start seeing reported cases of toxicity. The most recent study looking at , it was actually studied to look at the efficacy of vitamin D replacement but also it was studied to structured this way to understand how safe high doses and how high can you go? He did the study in multiple sclerosis patients and you titrated their intake of 40,000 units a day of D3 and as part of monitoring the study., he monitored calcium in the urine, calcium in the blood to look for any evidence that this going to be too much and he was measuring the blood levels. The blood levels did go up. These patients have 200 plus vitamin D levels, 200 nanograliter or more, at this 40,000 units. There was no calcium in the urine, there were no high calcium levels and on these patients were on this high dose for months, three or four more months. And then he ran to and back down, but what tells uses that there is a huge safety window of vitamin D from these lower doses that we're talking about 1000 units a day or 20,000 units per pound all the way up to this what I call hyper doses of vitamin D. I don't know that we have any logic to suggest why we need that much vitamin D but it's good to know that it's safe to expose to that much and not see any harm, so were many fold lower than that. It denotes that we're suggesting in the book and those are targeting blood levels around 50 nanograms per meal which were we think sweets somewhere between 30 and 50 where you want it all the time. But it's nice to know that you can take five to 10 times as much and you won't get any trouble and you can take those large doses. You can take those large doses for several months and you still won't get any trouble. You can take them for longer than three months to probably go into trouble, so large safety window in a fairly large therapeutic window for vitamin D.