TODD: Before we get to some of the basics of vitamin D, I wanted to cut right to the chase of what struck me. And that's that I read these claims that a vitamin D deficiency is the root cause behind a great deal of diseases and that it's a silent epidemic. Is that true? And is a vitamin D deficiency worse than other vitamin deficiencies?

DR. OKUNNU: Well, there's a lot of research that's been going on for decades about whether vitamin D has been important or whether it plays a role in certain disease processes. The important difference here is that a lot of studies have shown a relation between having low levels of vitamin D and things like asthma or cardiovascular disease, but they haven't shown that supplementation actually improves patient outcomes. So that's the problem. There's very conflicting resources about whether supplementation itself is beneficial versus just having the deficiency. And that also goes along with other factors revolving around those communities. So, people with low vitamin D levels can have different socioeconomic status. They can be raised differently just culturally. And maybe that has more of an effect on the disease process versus just the deficiency itself. So I would say, while vitamin D deficiency can play a role for sure, we don't know how conclusive the evidence is about supplementation for all of those things — and not just bone loss, but the other non-bone systems that it can affect. In regards to whether other vitamin deficiencies may be more important: Potentially, yes and no. You know, vitamin B12 deficiency has lots of factors as far as not just health of the blood systems but it can affect the nerves. So, it just depends on what you’re asking about, number one. And then, number two, the research and the data that supports certain vitamin deficiencies.

TODD: And vitamin D deficiency seems to be on the increase these days.

DR. OKUNNU: It is on the increase these days. And, so, part of the reasons why we think that is, is that a lot of people are now working indoors versus outdoors. So, we get a lot of our vitamin D from the sunlight. And as we are making a shift more towards not just living indoors, but doing a lot of our socialization indoors, we're decreasing the amount of natural vitamin D that we're getting. So, not just here, but in other parts of the world, we're seeing a rise in deficiency.

TODD: But hasn't that been going on for a long time.

DR. OKUNNU: The deficiency itself?

TODD: Well, if there's an increase and it's just because people are indoors, are people that much more indoors now than they were 20 years ago?

DR. OKUNNU: I would say so. You know, we're not only covering ourselves up more because we're aware of the other effects of sunlight — skin cancers. I think we are moving more indoors or protecting ourselves in a way that limits our ability to get vitamin D from the sun.

TODD: Talk a little about what vitamin D does its importance in bodily functions.

DR. OKUNNU: Yeah. So, Vitamin D is a hormone, but it processes the body through the kidney, through the liver, and then becomes the active form and helps with calcium and phosphate absorption in the body, to help fortify and mineralize the bone. So, primarily we know it's important for bone health, but it also has importance for muscle health as well as potentially. And maybe — depending on study — you're looking at immune support and cardiovascular and pulmonary support as well.

TODD: And what's the difference between D2 and D3?

DR. OKUNNU: So, the difference is how it's processed in the body. So vitamin D3 is actually processed a little bit easier, as far as it goes from D3 than through the liver, then the kidney and then the active form of it. Versus D2, which takes a little bit longer to process in the body to get to the active form. So, if you're to take a supplementation over the counter, our preference is vitamin D3 because we know it's more readily transported to the active form.

TODD: And is one of them by prescription, D2?

DR. OKUNNU: So you can actually get, I believe, D3 is more available over the counter. D2 is the prescription one should you have a really bad deficiency or really low levels. And providers typically prescribe D2 in the large international unit, typically 50,000 units.

TODD: What is the ideal intake? Is it still 600? Or was it moved up to 800 do I remember?

DR. OKUNNU: It depends on who you are. So, if you are eight-month-old or if you are a child less than 12 months, the recommendation is 400 international units. If you are one to adult age but not elderly — so around like 65 — then the recommendation is closer to 600. As you reach elderly, then our recommendation jumps up to 800.

TODD: Okay. And that's pretty consistent?

DR. OKUNNU: No, that's not consistent. It depends on who you're asking, what society you're asking. The consistency of all of those things is an infant. And, so, there is a general recommendation of 400 international units. The thing about that is if you're a formula-fed baby, then you're going to get all of that from formula. But humans don't make enough vitamin D through the breast milk. So then you really are looking at outside supplementation.

TODD: And what's the best way to get it? Is the sun the best way to get it?

DR. OKUNNU: The sun is a good way to get it, but there are other ways to get it. So, if you're going to have dairy products or if you're going to have fish — fish liver, specifically, but fish in general — fatty fish is a good way to get vitamin D. Or, I mean, these days, lots of foods are fortified with vitamin D, so whether that's grains or bread, you can get vitamin D that way as well.

TODD: If someone has a deficiency, is it is it easy? Is it an easy thing to fix?

DR. OKUNNU: It is pretty easy. So, if you have low vitamin D levels, so typically when we're checking blood levels — also deficiency is different depending on who you're asking — but, in general, if those levels are less than 30, then we know that you're deficient. If they're less than 12 then you're really low and should be on supplementation. Typically, it is easy to fix. It's either a once daily tablet or if you're really deficient, your provider may recommend a once weekly tablet.

TODD: And how much sun exposure is a good idea to get? Is like a 10- to 15-minute walk in the morning or late afternoon — when it's not, you know, top skin cancer hours — is that is that going to help you get it?

DR. OKUNNU: It really depends. So, about 10 to 15 minutes a day should give you about 200 international units, right. But, again, that's difficult to measure. And I can't give you an exact measurement, but of course, that's going to be beneficial as long as you're also wearing skin protectant. But the other thing to know is that depending on who you are, your ability to really get that vitamin D from the sun. So, if you have more melanin, you're not going to get as much vitamin D as someone who maybe is more pale. And, so, you may need more sun exposure to get the same amount of vitamin D from the sun.

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ZACH: Dr. Okunnu mentioned some ways to get your vitamin D, but we wanted to drill down deeper to let you podcast listeners know all your options. Before we start, you need to know how to read labels. They may show vitamin D in either international units or in micrograms. The daily recommendation for adults under 70 is 600 international units or 15 micrograms. Cow's milk may be the first vitamin D source that comes to mind, but the truth is, it doesn't occur naturally in cow’s milk. Since the 1930s, however, virtually all milk manufacturers have been adding it. That goes for alternative milks, as well — almond, soy, oat, rice, coconut. Yogurt is also fortified with it, so is a lot of orange juice. But none of those give you a lot of vitamin D in one glass per serving. In the case of yogurt, it typically supplies 1.5 micrograms to three micrograms. That translates into 60 to 120 IUs. The best source is cod liver oil, a tablespoon of which has a whopping 1360 IUs of vitamin D. If that doesn't sound tasty, rainbow trout, salmon, swordfish, tuna, herring and sardines are all great sources. The vitamin D in a common serving of the different varieties ranges from 320 to 720 IUs. Mushrooms are another good source. A three-ounce serving provides about eight micrograms of vitamin D. One egg, primarily the yolk, provides about the same amount. Finally, milk and yogurt and orange juice aren't the only products fortified with vitamin D. You can easily find vitamin D in cereals, oatmeal and bread.

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TODD: And now back to our conversation with Dr. Okunnu. So why do deficiencies occur?

DR. OKUNNU: Lots of reasons these days. Whether that's nutritionally — if we're not taking in enough vitamin D. We're not getting enough from the sun. Or if you have a problem with your liver and your kidneys. So, I know we talked earlier about the way that the vitamin D is processed through the body. You know, you're getting this inactive metabolite from the sun or from food. And, in order for it to actually be beneficial and helpful in your body, you have to have it processed through your liver and through the kidney. So, if you have chronic kidney problems, chronic liver problems, any potential way through those organs that isn't allowing it to become active is going to become a problem. But, also these days, there's also intestinal absorption issues, so Crohn's disease, celiac disease — any one of these malabsorption issues that isn't allowing vitamin D to be absorbed into the system. If you're taking it orally, then you're going to have a problem with getting it to create more calcium in your body to help with the bones.

TODD: And is it sometimes kind of a mystery why people get it?

DR. OKUNNU: Oh, definitely. If you're deficient in vitamin D and you're taking appropriate supplementation and your levels are still low, then we have to go down the hole of, well, why is it still low? Check your liver. Check your kidney. Check for absorption issues. And if it's all normal, then it can still be a mystery. And we don't know exactly why someone can have it.

TODD: And, among those at risk, people with darker skin as well?

DR. OKUNNU: Yes, for sure. I think I was reading a recent study that said over 90% of individuals with darker skin are deficient in vitamin D. They may not have symptoms of vitamin D deficiency, but their levels are low.

TODD: What are signs you're not getting enough?

DR. OKUNNU: So, if you asked this question 20 years ago, the answer would be, how are you feeling? Tired? Are you feeling more down and depressed? Because those were some signs of vitamin D deficiency. But, these days, honestly, most people have no symptoms. We only see really bad symptoms when it comes to things like rickets in kids or in adults, meaning you're actively having demineralization of the bone from low levels. Symptoms typically aren't present these days. The older studies that show that it could lead to more fatigue or signs of depression have actually been kind of debunked. So honestly, a lot of people don't have any symptoms.

TODD: Is it not a bad idea just to take a supplement?

DR. OKUNNU: It's not a bad idea. So, if you say that you don't have a good intake of vitamin D — naturally in foods, or if you're not getting a lot of sun exposure — it's not a bad idea to take supplementation, as long as you're taking the appropriate amount. So, over the counter, you can find, you know, 400, 800, 1000, 2000 or 5000 international units of vitamin D3. However, if you're taking more than 4000 units, then you're more at risk of having signs of vitamin D toxicity. So that's the thing to be careful about is, yes, you can take it, but make sure you're not taking too much.

TODD: At the beginning, you mentioned supplementation. Is the jury sort of still out on that to treat vitamin D deficiency more than to prevent it?

DR. OKUNNU: So not to treat it, but more to test for it to begin with. So, I'm family medicine. And the Academy of Medicine actually does not recommend routine testing of vitamin D deficiency in asymptomatic individuals at all. And that’s like a Class C recommendation. So that's where the jury's out, not just on testing for it to begin with but also how much is appropriate to supplement with and whether it's beneficial in non-bone related disorders.

TODD: So, people can be deficient and…

DR. OKUNNU: Never have any problems.

TODD: And have no idea that they're…

DR. OKUNNU: And never even know.

TODD: And getting too much can be a bad thing?

DR. OKUNNU: It can. So, you know, whenever someone takes too much vitamin D, I always like to give people the analogy of plastering a wall. So, yes, if there's a hole in the wall, you want to build it up real nicely. You want to make sure that we're building it up nice and strong. But there's such a thing as building it up too much so that it becomes weak. And that's when the demineralization or the rickets happens as well. They can also have signs of calcium excess, whether that's vomiting or kidney stones or headaches. So, there's lots of signs and symptoms that can happen from too much vitamin D.

TODD: So, I read that the Endocrine Society Practice guidelines recommend up to 10,000 IUs is safe a day. How can that be?

DR. OKUNNU: Oh, that sounds quite excessive. But, like I mentioned, you know, every society you ask is going to have a different answer as far as what's okay. And the reason why I think vitamin D supplements are widely available is because the risks of toxicity — and I've never seen toxicity — but the risks are so low. And, so, while some studies will show 4000 day is fine, I know people who take far more than that and still don't have the signs that I just mentioned, the symptoms of toxicity.

TODD: Coming back to my sort of original question, the different things that it may cause it. I did a Google News search yesterday and I came across stories about new studies showing the deficiency can cause dementia, stroke, miscarriages. What kind of effect can it actually have?

DR. OKUNNU: So, I did that same Google search, just to see what was out there. And when I try to follow it up with actual, published, you know, well-controlled studies, the relationship is, yes, low levels can be linked to dementia or miscarriages, but supplementation to fix those deficiencies haven't led to improved outcomes of the dementia or of the miscarriages, if that makes sense. So, my concern is, is it more related to other aspects of those populations and not the deficiency itself, because supplementation hasn't shown any improved outcomes?

TODD: Do doctors check for vitamin D deficiency pretty regularly?

DR. OKUNNU: We do. The crazy answer to this is it depends on the patient, the provider and your insurance. So, you know, you come in for your annual physical. And, unfortunately, there's a lot of insurance providers who won't cover for vitamin D. And people ask me all the time, well, how much is it going to cost? And I have no idea. I do check for it. So, if someone asks me to check for it, I do. But otherwise I don't routinely do it because we know that it may not play a role in their overall health in general, as far as outcomes.

TODD: It's just a blood test, right?

DR. OKUNNU: It's just a blood test.

TODD: So, it shouldn't be too terribly expensive.

DR. OKUNNU: I would hope not. I haven't had a bunch of complaints, but I've also had people kind of want to fight a bill for it too.

TODD: But it doesn't sound like it's such a…

DR. OKUNNU: It's not thousands of dollars.

TODD: Right. But I'm just saying, it doesn't sound like it's such a huge — what I read — silent epidemic. And can be cause of so many problems, if doctors aren't rushing to do this more with patients.

DR. OKUNNU: No, it's not. So, like I mentioned before, if this was a conversation 20 years ago, I'm sure people would have a different answer as far as how it could lead to certain health outcomes. But these days, you know, we're not seeing a bunch of rickets or bone loss or significant problems in our country because of vitamin D deficiency.

TODD: But you do get people still asking you?

DR. OKUNNU: All the time.

TODD: Why do you think that is?

DR. OKUNNU: I think part of it is, number one, the Internet. You know, of course, you're going to read things that say, yes, it can lead to X, Y and Z problem. And, if it's easy to test, easy to fix, why not do it? Especially if the benefits could outweigh the risks. So, I think that's why people are asking for it and because it's something that's been around for a long time. It's years and years of the same thought process that this is going to affect my health in this way. So why not get it checked and do something about it? And I think we're kind of shifting to a society that's more focused on alternative ways of medicine. So, whether that's through herbs or supplements, vitamins, I think a lot of our side is making a shift and trying to do things other than just standard Western medicine.

TODD: Is there anything you want to say, sort of a final thought on this, final takeaway for people out there listening to this podcast about how they how they should think about vitamin D deficiency.

DR. OKUNNU: I would say do your research. Things are changing every day. And while it's not going to hurt to take some vitamin D in the form of sunlight, through your nutrition or through supplementation, it's also important to make sure that you're taking something for a good reason, not just for the fun of it.

TODD: All right. Very good. I appreciate your taking time to talk with us about this.

DR. OKUNNU: Thank you for having me. Appreciate it.

[End of the interview]