Take Vitamin D? That Might Not Be Enough, Here's Why!

Interviewer: When you supplement vitamin D. In your book you also mention the importance of calcium, vitamin A, magnesium. How important is it to not forget about some of those as you are trying to balance your vitamin D levels?

Dr. Dowd: So as I was learning about vitamin D, it became clear that there are a number of complementary nutrients, okay? And you can think about this at the vitamin D receptor. Now this isn't going to be some technical discussion, but when vitamin D binds to its receptor, it binds in conjunction with another receptor called the vitamin A receptor or RXR receptor. So vitamin A and D are very closely linked partners. They do almost everything together, okay? So that tells you something about what other nutrient you might need. You probably need vitamin A for vitamin D to work optimally.

In contrast, too much vitamin A will inactivate vitamin D. So you do not want too much vitamin A, but you want enough. Now where does the vitamin A come from? Vitamin A comes in nature. Again, this is using nature as your guide to understanding the biology. Vitamin A comes from vegetable matter, okay? So plant matter is where a lot of vitamin D comes from, or organ meat from animals. Liver, kidney, these sorts of things. So plant matter [inaudible 00:01:15] vitamin A and so what else might be in plant matter that might enhance vitamin D function? Well it turns out that when we looked at studies, older studies on rickets, and there are actually some newer ones, it became clear that when kids were deficient in magnesium, it took a lot more vitamin D to correct their rickets than if they were replete with magnesium. So magnesium deficiency makes you resistant to vitamin D.

So where does magnesium come from in our diet? Green leafy vegetables again. Okay? So magnesium is a mineral that is required for chlorophyll to work. No chlorophyll, no plant life. No plant life, no animal life. Okay? So when you eat chlorophyll, plant matter, or supplements based on real foods, your'e getting magnesium in a chelated form. It's chelated to what? Chlorophyll. The protein chlorophyll. And so it's much better absorbed in that form. That was nature's intention. And so magnesium enhances vitamin D function. Vitamin A enhances vitamin D function. But not too much A.

And the type of A you are getting from plants is what? Carotenes. All the different types of carotenes which are safer forms of vitamin A than retinol, which is an activated form of vitamin A, which can be toxic and adversely affects vitamin D function. So you want retinoids in the form of carotenoids. You want magnesium. And then there's another thing in plants. Folic Acid. And we have learned recently that folic acid, through epigenetic mechanisms, alters the function of vitamin D enzymes. The one that activates the pre-hormone to the active hormone and it depresses the one that inactivates vitamin D.

So when you have plenty of folic acid around, it's gonna be easier for you to activate your vitamin D and it will hang around a little longer before it is deactivated in the presence of folic acid. So, and where does folic acid come from? It is like a broken record in here. Green leafy vegetables again. So this is how mother nature is telling you, look these things are really important. There is all these micronutrients that come here and they are all enhancing the effect of something else. In this case vitamin D. And so you really want your lifestyle to be a reflection of all of these things if you want to optimize vitamin D function.

Interviewer: So if we have to, and a lot of us will have to supplement vitamin D, that's where the diet part comes in because those two will interact so the diet and the supplement will help [inaudible 00:03:50] to the optimum.

Dr. Dowd: Correct. Which...right. So that's what I talk about in the book. Some of it is acid base equation and that gives you a way of thinking about it that you can actually calculate things. But the idea is to get a lot of vegetable matter to complement the lean protein, and then make sure that your vitamin D levels are normal. And it is the vegetable matter in this diet that is complementing the function of vitamin D. But you can also look at it this way. Vitamin D not only helps you absorbs calcium, but about a third of your phosphorous absorption depends on vitamin D and phosphorous is one of the building blocks that you absorb from protein ingestion. So vitamin D is enhancing your ability to assimilate protein as well. So you see, everywhere you look, there's a connection. And it is all reflected in what we see when we look at the animal world, of why animals...what their diets are like and activity levels are like and it all has a purpose, and it all is there for a reason. And when you explore the vitamin D picture the same way, you see how it is tied to so many different things.