FoundMyFitness - #009 Rhonda Answers the Most Popular Questions About Vitamin D

Episode Date: August 6, 2015

Dr. Rhonda Patrick answers some of the most popular questions regarding vitamin D including: (00:00) Introduction (02:22) How do you decide how much vitamin D to supplement with? (12:51) Is it possible to get too much vitamin D? (20:52) Is there a difference between vitamin D made from the sun versus a supplement? (24:43) What form of vitamin D is more bioavailable or absorbed better? Join over 300,000 people and get the latest distilled information straight to your inbox weekly: https://www.foundmyfitness.com/newsletter Become a FoundMyFitness premium member to get access to exclusive episodes, emails, live Q+A's with Rhonda and more: https://www.foundmyfitness.com/crowdsponsor

Hello, guys and gals. In this episode of the Found My Fitness podcast, I address some of the most popular questions regarding vitamin D, including how do I decide how much vitamin D I should supplement with? Can you get too much vitamin D? Is there a difference in vitamin D made from the sun versus a supplement? And what form of vitamin D is more bioavailable and absorbed better? But before we dig in, disclaimer. keep in mind that the information in this podcast is not intended as medical advice. It is for informational purposes only and run it by your physician if applicable. Also in this podcast, I refer generally to some gene polymorphisms which change the conversion and function of vitamin D.

To learn more about these gene polymorphisms, you can sign up for my newsletter at foundmyfitness.com and you'll be notified when I release a new tool on my website, hopefully. very soon that can help you understand some of your raw 23 and me data allowing you to explore information that ties to your unique genotype and may tell you about your own individual metabolic idiosyncrasies. The newsletter is also your gateway to podcast notes and in-depth articles I simply do not share anywhere else online. The sign-up form can be found at foundmyfitness.com. Finally, this episode of the Found My Fitness podcast is sponsored by people like you. So if you like it or otherwise find the information in it valuable, please consider signing up to

contribute $5 per month, which is right about the cost of a latte these days. My goal in a nutshell, if I can achieve my next funding milestone, is to ramp up the frequency of my podcast and videos by getting a little bit of production help and possibly even take a year to distill down as much information as I can into a book. Sounds like worthy goals, right? Great. So you can find out more about this on my website, or you can head right over to my crowdfunding page at Patreon, p-a-t-r-e-on-com

slash Found My Fitness. Now on to the podcast, starting with the most frequent question I receive about vitamin D, which is, how do I decide how much vitamin D to supplement with? Unfortunately, I don't have a simple answer for this question, because there are many factors that regulate vitamin D levels in the body. For this reason, I think it is very difficult to have a one-size-fits-all recommended daily intake. I can, however, give you a guideline and explain the reasons for this. Vitamin D gets converted into a steroid hormone. You actually make it in the skin from UVB radiation

from the sun. But there are many factors that can interfere with this process. Since UVB light from the sun is the primary source of vitamin D, anything that blocks UVB light also inhibits the ability of the skin to produce vitamin D. Things that directly block the efficiency of this process include sunscreen, which filters out UVB radiation, melanin, which is the dark skin pigmentation that acts as a natural sunscreen, living in a northern latitude such as the northern U.S. and Europe, because during the fall and winter months, UVB radiation does not make its way into the atmosphere in these northern regions. Even in a completely ideal situation for vitamin D synthesis, age also has a profound effect

on your skin's ability to produce vitamin D, such that a 70-year-old produces only about 25% of the vitamin D from the same amount of sun exposure that they would if they were formally 20 years old, all other factors aside. So the vitamin D we can make in our skin from the sun clearly has many factors regulating that alone. In addition, the amount of body fat also plays. plays a role, though not by affecting synthesis. Vitamin D is a fat soluble vitamin.

This means a higher body fat composition impairs the bioavailability of vitamin D because the fat itself acts as a sink preventing the vitamin D from being readily released into the bloodstream where it makes its way onto the liver and then the kidneys to be converted into the active vitamin D hormonal form. There are also gene polymorphisms which are variations in the sequence of DNA of gene that alter the function of that gene in genes that convert vitamin D3 into the more bioactive forms. These gene polymorphisms affect the way vitamin D3 is converted into the precursor to the active

hormone form of vitamin D, which is the major circulating form of vitamin D that is measured in blood to indicate a person's vitamin D levels and it's called 25 hydroxy vitamin D. So to circle back to the question, how do I decide how much vitamin D to supplement with? must first look at what is considered to be an adequate level of vitamin D. A blood level of vitamin D of 25 hydroxy vitamin D, the precursor to the active vitamin D hormone, below 20 nanograms per mill is considered deficient. Less than 30 nanograms per mill is considered inadequate, and levels somewhere between 30 to 80 nanograms per milliliter are considered adequate, at least by the Endocrine Society, which bases their recommendations off of

findings from the scientific literature. I have read personally countless studies on vitamin D and have also published two studies on vitamin D and have come to the conclusion that there is a sweet spot when it comes to vitamin D levels. I have read 32 studies that analyze blood levels of vitamin D between the years of 1966 and 2013 and the association with all-cause mortality, meaning causes of death that are not accidental or self-inflicted and include cancers, all types of heart disease, respiratory diseases, strokes, diabetes, organ failure, etc. These studies have shown that blood levels between 40 nanograms per milliliter and 16 nanograms per milliliter are associated with the lowest all-cause mortality. In line with this, other studies that I have read have shown that blood levels of

vitamin D between 40 and 60 nanograms per milliliter are also associated with the longest telomeres in white blood cells. Telemere length is a biological marker for aging, and the longer the telomere length, the younger the biological age. Tilemere length is also a proxy for how much damage has accumulated inside of the cell because damage accelerates telomere shortening. So the more damage that occurs, the shorter the telomeres get. And another study that was done in about 2,100 twins found that those twins with the lowest vitamin D levels, which happened to be less than 20 nanograms per milliliter, had a telomere length that corresponded to about five years of biological aging.

So with all of that science, I have seen, it seems to indicate that blood levels of vitamin D between 40 to 60 nanograms per milliliter is the sweet spot. The question is, how do we achieve that level through supplementation? Well, it takes about 1,000 IUs of vitamin D3 per day to raise blood levels by 5 nanograms per milliliter. So what that means is if a person starts out deficient, say their blood levels are around 20 nanograms per milliliter, then they would need to supplement with 2,000 I use a vitamin D a day to bring themselves up to an adequate vitamin D status of around 30 nanograms per

milliliter. And they would have to supplement with around 4,000 IUs per day of vitamin D3 in order to bring themselves up to what I call the vitamin D sweet spot, which is around 40 nanograms per milliliter. This is why I personally take 4,000 I use of vitamin D3 per day. And my levels generally hover around 45 to around 53 nanograms per milliliter. But I also do not get a lot of sun. I wear sunscreen and I do not have gene polymorphisms altering the way vitamin D3 is converted into these precursors for the active vitamin D steroid hormone. So at the start of this podcast, I mentioned how UVB radiation from the sun is the primary

source of vitamin D and certain factors like sunscreen, skin. skin pigmentation, living in a northern latitude, and also age, all affect whether you can make vitamin D in your skin from UVB light. This is important to keep in mind when determining how much vitamin D to take. For example, I have a friend who lives in Los Angeles, California, which is Southern California, lots of sun, UVBs hitting the atmosphere, you know, most of the year. And she's also outside a lot. She works in the garden and she really has a tan to show it. So she began supplementing with 5,000 IUs per day for a couple of months. And then she got her vitamin D levels measured. And her levels were 90 nanograms per milliliter, which is definitely too high. It's not in the

vitamin D sweet spot. So she cut back on her vitamin D and she takes around 2,000 IUs per day now and had her levels measured again, and now her levels are about 50 nanograms per mill liter. So I think the point is, is that you really need to figure out how much sun you're getting, you know, depending on where you live, how old you are, you know, how much body fat you have. And, you know, if you're not getting a lot of sun, if you're elderly, and you wear sunscreen, or you have a natural sunscreen built into your skin, because your skin color is a little darker, then 4,000 IUs a day of vitamin D3 may be a good start. But if you do get a lot of sun, a lot of sun, and you're light-skinned, you're young,

you live somewhere that, you know, like Southern California or Arizona, you know, places where UVB lights hitting the atmosphere most of the year, then possibly you may not want to exceed 2,000 IUs a day. But really, the best thing that you can do is to get your vitamin D levels measured. And this really, really becomes critical in cases where a person has a gene polymorphism that renders their body less efficient at converting vitamin D3 into the precursor for the active vitamin D hormone called 25 hydroxy vitamin D. You know, a person can supplement with 4,000 I use of vitamin D3 a day and they think

they're getting adequate levels, but they actually may have one of these gene polymorphisms in the vitamin D pathway and find out that they're actually not getting adequate levels of vitamin D. So I'll give you an example. I have a friend that has actually I've got a couple of friends that this has happened to, but one in particular, she has one of these polymorphisms, and she's always been vitamin D deficient, couldn't get her levels up. She was taking 4,000 IUs a day. Finally, she had to up her dose to 10,000 IUs a day.

a day of vitamin D3 just to get her vitamin D levels to 30 nanograms per milliliter. So, you know, that's a perfect example of someone that would never have known they had this gene polymorphism or that they weren't getting adequate levels of vitamin D if they hadn't gotten their vitamin D levels measured. Now, 10,000 I use a day is a vitamin D3 is pretty high for people that don't have these types of gene polymorphisms. So that's something to keep in mind. But you see why it is important to get your vitamin D levels measured, ideally before and after you begin supplementing, but at the very least a month or two after you have began, after you've been supplementing. So I think generally

speaking, 4,000 I use a day is a pretty good dose for most people that are not obese, not getting a lot of sun inside a lot. And 2000, I use a day, may be a pretty good start for people that are also not obese, but do get a lot of sun, live in Southern California or other places that are not in northern U.S., etc., etc. So on to the next question. Can I get too much vitamin D? Well, the answer is yes. That's the short answer. But on the topic of vitamin D toxicity, D. And can you get too much vitamin D? Vitamin D is extremely important, but too much of it can be bad. You know, like many things in biology, it's all about the dose.

Just because something's good for you doesn't mean you want to take excessive amounts of it. And sometimes people have a hard time understanding that. So, you know, data has been compiled from several different vitamin D supplementation studies. And it's shown that, you know, acute vitamin D toxicity is, you know, is obtained at doses higher than 10,000 IUs a day for some adults. And as far as all-cause mortality and vitamin D goes, I mentioned that there's a sweet spot for vitamin D levels that is between 40 to 60 nanograms per mill-liter.

The reason that is a sweet spot is because vitamin D levels below that and vitamin D levels above that were associated with a higher all-cause mortality, which means there was a U-shaped curve in terms of mortality. So very low levels of vitamin D are associated with higher all-cause mortality, and very high levels of vitamin D are also associated with a higher all-cause mortality. And this is actually something similar has been shown in mice. So in mice, both too high and too low vitamin D levels cause the same premature aging phenotype.

So I think this is really important to keep in mind. Again, just because something is good for you does not mean you need to consume it in excess quantities because this can often lead to the opposite effect that you were trying to achieve in the first place. So toxic doses of vitamin D can really, part of the toxicity has to do with high levels of calcium in the blood. And this is known as hypercalcelsicine. this can occur, this can acutely occur.

And what I mean by that is that if someone were to take a really high dose of like 50,000 I use of vitamin D per day for a few days, then you can have this acute effect where you have hypercalcemia and, you know, all sorts of bad things can happen. But one thing to keep in mind is that you can also get high levels of blood calcium without really knowing that's occurring. So vitamin D dramatically increases the dietary absorption of calcium. So if you have an adequate level of vitamin D, you know, around 30 nanograms per milliliter, the absorption of dietary calcium increases to 40%. So you'll absorb about 40% of the dietary calcium that you consume in your

food, etc. Whereas if you are vitamin, D deficient, so if you have vitamin D levels below 20 nanograms per milliliter, then you only actually absorb around 10 to 15% of your dietary calcium. Not very good. But why is this all important? So increasing your dietary absorption of calcium can be a great thing if the calcium goes to the right place, like your bones or your other tissues that need calcium. Calcium. Calcium. Calcium. is a co-factor for many different enzymes, so it's required to run a lot of metabolic reactions in different tissues in your body. But high calcium is not a great thing if it sits around in your blood vessels because too much calcium in the bloodstream can easily form a calcium

phosphate crystal. And that's the beginning of an atheroscotic plaque, which can form you know, these plaques that aggregate in your blood vessels and arteries that can cut off circulation to the brain and cause a stroke and can cut off circulation to the heart, depending on what artery it's in and result in a heart attack. So that's not good for your heart, not good for your brain. There are other genes in your cells that make proteins that can carry calcium out of the bloodstream, out of the blood vessels, and bring it to your bones where it's supposed to go, bring it to other tissues. These proteins are called osteocalcin or matrix glaw protein, for example.

And they require vitamin K to become activated. There are two biologically active forms of vitamin K, vitamin K1 and vitamin K2. And I'm really not going to go into too much detail on this. I can talk about this another point, but I will just briefly cover some of this. So vitamin K1 is found in dark, green leafy plants, mostly, and vitamin K2 is most prominently found in fermented foods like fermented soybeans called natto. And it's also made in our gut by our gut bacteria, presuming that we have the right types of gut bacteria. And that's a whole other issue. The major difference between vitamin K1 and vitamin K2 is that K1 readily goes to the liver to activate proteins that are involved in blood clotting, which is very important. K2, vitamin K2,

does not go to the liver as readily as vitamin K1 does. And instead, it stays around in the bloodstream, in the blood vessels, where it can activate proteins like matrix gall protein, osteocalcin. I don't want to get too technical here, but those those proteins that are involved in moving calcium out of the bloodstream, bringing it to the bones, bringing it to other tissues where it should be to do the functions it's supposed to do. Now, vitamin K1 can also do this, but it has to go to the liver first and make sure that there's enough K1 to maintain blood clotting. That's an essential function for survival. And once there's enough vitamin K1 to do that, then K1 stays around in the bloodstream and also does the same thing that K2,

vitamin K2 does and activates those proteins that move calcium out of the bloodstream. and brings it to the bones, to the other tissues where it should go. So I think it's very important to have enough vitamin K1, and I also like having vitamin K2 in the body to make sure that all the dietary calcium that is absorbed, particularly if you're absorbing 40% of your dietary calcium, if you have adequate vitamin D levels, making sure that the calcium is going to the right place and doesn't form these calcium phosphate crystals in the blood vessels. So as insurance, I take around, I supplement with around 50 micrograms of vitamin K2 per day, and the vitamin K2 is from a natural nato source. So that

was sort of me rambling on on this issue of toxicity, and I, you know, I think that a lot of the vitamin D toxicity has to do with too much calcium that can sit around in the bloodstream. and really, you know, you don't want to take too much to vitamin D. So you want to be in that sweet spot, 40 to 60 nanograms for a millimeter. But also I think it's good to make sure you have, you know, these other vitamins and minerals are also very important. Vitamin K1, vitamin K2 are examples of that, how it's important to make sure the calcium that you are absorbing is going to the right place

and not causing problems by accumulating and precipitating in your blood vessels. on to the next question. Is there a difference in vitamin D made from the sun versus vitamin D supplements? The short answer is yes, there is a difference. So there has been a lot of discussion as to whether ingesting vitamin D from a supplement is the same as producing vitamin D3 in the skin. As I mentioned, vitamin D is made in the skin. upon UVB radiation exposure from the sun.

And in the skin, something called 7 dehydro cholesterol is converted into vitamin D3, but this requires exposure to UVB light. And vitamin D3 is then transp-B-3, vitamin D3 then gets released into the bloodstream through this whole process that I am, that's way too technical and I'm not going to get into. But once it's released into the bloodstream, it's then transported to the liver, where it's converted to the precursor to the hormone called 25 hydroxy vitamin D. Again, the 25 hydroxy vitamin D is the major circulating form of vitamin D and is what most people measure to determine vitamin D status.

Then after it goes to the liver, it's taken to the kidneys, where it's then converted into the active vitamin D hormone, which is called 125 hydrotechlor. hydroxy vitamin D. So let's get back to the difference between vitamin D3 made in the skin versus vitamin D3 taken as a supplement. 100% of the vitamin D3 that is produced in the skin is available to be released into the bloodstream, where it can then be taken to the liver and the kidneys, et cetera, et cetera. whereas a vitamin D3 supplement, when it's taken orally, after it's absorbed, which I will

address in the next question, only about 60% of it is available in the bloodstream to be carried to the liver and, you know, et cetera. So about 40% of the vitamin D3 that's taken orally is cleared in what is called the lipoprotein bound fraction. So this means, that vitamin D3 made from the sun is more bioavailable than vitamin D3 taken from a supplement. And that's it. That's the only difference. They're the same other than that. But one thing to keep in mind is that making vitamin D3 from UVB light, UVB radiation,

does come at a tradeoff. And UVB radiation causes DNA damage by causing, break in the DNA strand. And this not only happens in skin cells, it happens in immune cells. It's been shown in other tissues as well, and it accumulates over time. So the more it occurs, the more it accumulates. The accumulation of DNA damage is one of the major cellular mechanisms of aging, of the aging process. So DNA damage leads to, you know, potential cancer-causing mutations or just mutations that change the functions of genes, make them work less. efficiently. So you can make a gene that's important for antioxidant function not work as well

or a gene that's involved in repairing DNA damage not work as well or etc. It also, the accumulation of DNA damage also causes telomeres to shorten much more quickly. And this is because telomeres, one of their functions is to protect your DNA. So when there is damage in the cell, they take the hit. And so they protect your DNA by taking the hit, but as a consequence, your telomere shorten more quickly, which then in stem cells can cause your stem cells to die quicker. So you get the point, DNA damage is not good. And this is why I personally choose to supplement with vitamin D rather than make it in my skin. So on to the next question. The question is, what form of vitamin D is more bioavailable and absorbed better.

So I'm going to answer this question in two parts. The first part of the question has to do with bioavailability. So there's two forms, and then we're talking about supplemental vitamin D here. There are two forms of vitamin D, vitamin D2, and vitamin D3. vitamin D3, as I mentioned, is made in the skin after exposure to UVB radiation. And you can also take vitamin D3 as an oral supplement. And that's mostly made from or sourced from fish. And vitamin D2 is produced in some plants, but largely in fungi, such as mushrooms,

after they have been exposed to UVB light. So both vitamin D2 and vitamin D3 get converted into the precursor for the active vitamin D hormone. So they get converted into 25 hydroxy vitamin D. Multiple studies have shown that vitamin D3 is better at raising serum levels of 25 hydroxy vitamin D than vitamin D2 is. And that's clear, you know, that's, it's pretty clear that's been shown in multiple studies. However, the mechanisms for this are still not clear. So there's several, you know, possibilities and theories that have been raised and proposed by people,

scientists, are trying to figure out why vitamin D3 is better at raising the precursor to the vitamin D hormone levels, the 25 hydroxy vitamin D better than vitamin D2 is. So the empirical evidence is clear. Mechanisms still trying to be figured out. but, you know, what this means is that, you know, if you're a vegetarian and your source of vitamin D is from D2, then you probably just have to get your vitamin D levels measured after taking a vitamin D2 supplement because the measurement in which I talked about earlier in the podcast where I said taking vitamin, taking 1,000 I use of vitamin D3 can raise serum levels by five

nanograms per milliliter does not, that does not mean vitamin D2. That means vitamin D3. So you really have to figure out how much vitamin D2 you need to supplement with to get what I call the vitamin D sweet spot levels of 40 to 60 nanograms per militer. So the second part of this question has to do with absorption. So vitamin D is fat soluble, which means that it's absorbed in the intestine similar to other lipids and in the intestine, vitamin D associates with lipid particles that aggregate together and form a spherical shape, and this is called a mycel. And these myceles with vitamin D associated to them are then taken up and absorbed by gut cells called enterocytes. So the presence of fat stimulates the release of bile acids, which then is required to promote the absorption of these mycils with vitamin D. So for this reason, vitamin D that is in a carrier oil, such as olive oil, will slightly increase the viability of vitamin D compared to vitamin D in powder form, for example.

And that has been shown. Similarly, taking a vitamin D supplement with or immediately after a meal that has some fat in it will also slightly increase vitamin D absorption in the gut. And so this has also been shown empirically. I personally take 4,000 I use a vitamin D3 that is in olive oil. Olive oil is not very prone to oxidation because it's monosaturated, not polyunsaturated. So you want to make sure if you're taking a vitamin D supplement, usually soybean oil is very prone to oxidation and not a great source of carrier oil. So I get mine from now brand, but there are some other brands out there.

There's also a supplement from Swanson brand that is in MCT oil, so medium chain triglyceride oil. But that is at a lower dose. I believe it's around 1,000 IUs, so you'd have to take more of them. So that's it for today. Thank you for listening, everyone. And I hope you learn something from these answers to these popular. questions. Next week, Aubrey de Grey will join me to talk about all things aging. So I will talk to you guys again soon.