The following is a transcription of part 1 of Dr. Michael Holick's January 22ng, 2013 webinar on Vitamin D & the Sun: What does the sun do for me? To view the visuals and slides, click here. The two windows can be minimized and placed side by side for concurrent viewing.
Vitamin D & the Sun: What does the sun do for me?
Carole: Welcome to GrassrootsHealth’s new Webinars called ‘Scientists Answer Your Questions”.
GrassrootsHealth is a public health promotion and research organization, whose primary purpose is to help solve the vitamin D deficiency epidemic. I’m Carol Baggerly, director of GrassrootsHealth, and we’re absolutely delighted to have such interest in this program. Currently today, we have over 200 registrants listening to this program; we’re absolutely delighted. I want to give a special “thank you”, to those that are helping spread the word about this series: Dr. Northrup has a great number of attendees out there, Dr. Cannell of the Vitamin D Council, and Dr. Joe Prendergast; all of those people, would you please (if you participate in their programs) give them a ‘thank you’ for referring you. Also, we have a great number of our own study participants and we are very, very thankful that you are taking advantage of this. We will be providing a free Vitamin D test kit to invite any additional people into our Vitamin D study, it’s open to everybody and you can find out about this on grassrootsHealth.net. Our key event today, of course, is Dr. Michael Holick. Dr. Holick is a key leader in the field; greater than 30 years’ experience in Vitamin D promotion, he’s also, (I think) a bigger traveler than I am. He travels all over the world and has for many years; promoting the use of Vitamin D and all of its benefits. So, without any further ado from me, Dr. Holick, it’s all yours; “what does the sun do for me?”
Dr. Holick: Welcome all, hopefully I can give you a very broad overview about Vitamin D, and hopefully I’ll convince you that it is a delightful vitamin and what I’m going to do is to talk about sunlight for your health and most importantly, I get support from NIH (formerly from the UV Foundation and also from the Mushroom Council) but much to the dismay of the dermatology community, also get support from The Sun. I think that, as you’re well aware, Vitamin D deficiency is a very common problem and that essentially everyone, globally, is at risk and we now recognize that Vitamin D isn’t only for the prevention of Rickets, but may be important for preventing Osteomalacia (a painful bone disease that often adults can acquire, especially during the winter time), also diabetes, multiple sclerosis, rheumatoid arthritis, infectious diseases, hypertension, heart disease, many cancers have been associated with Vitamin D deficiency and that link with Sun exposure and Vitamin D, has given us a great insight into many of these disorders. And so, whether you’re an amphibian or a reptile or a bird, or a lower primate, they’ve always depended on the Sun for their Vitamin D requirement. In fact, I always wondered about our hunter-gatherer forefathers (and there’s been a lot of talk about Neanderthals), recently their DNA has revealed that they weren’t dark, hairy creatures but rather, they were Celtic skin, with very light skin; redheaded. The reason is that, as they migrated North and South of the Equator, that it was necessary for pigmentation to have devolved, in order for them to have made enough Vitamin D and the major function, certainly, was for a female to have a normal pelvis, so that she’d be able to procreate. We know that women who are Vitamin D deficient, in utero, in their first few years of life, often have a flat/deformed pelvis and have a very difficult time with child birthing.
So, how do you make it? It turns out that it’s the precursor of Vitamin D is 7-dehydrolcholesterol; it’s the precursor of the cholesterol bio-synthetic pathway. Now, you may wonder, if you use a statin and it inhibits cholesterol bio synthesis, will that be a problem? The answer is “no”; statins don’t get into the skin, will not influence Vitamin D production in skin. It’s always been an issue, whether or not if you were a lifeguard or a sun worshipper, would you make too much Vitamin D in your skin, the answer is “no”, because Mother Nature cleverly designed the system, so any excess exposure to sunlight rapidly destroys any excess Vitamin D, so you can never become toxic from Sun exposure.
I’m always asked the question, “Is there any difference from taking a Vitamin D supplement and being exposed to sunlight and making Vitamin D and the answer is: “yes”. Many years ago research showed that Vitamin D produced in your skin, lasts 2-3 times longer in your body than it does if you take it as a supplement. For us, in 1921, it was Hess and Unger (two physicians, in NYC) that demonstrated when you exposed children to the roof of a NYC hospital; they demonstrated they can cure Rickets. In 1931, our Government actually set up an Agency, telling parents to put your kids outside, to get some sensible Sun exposure. In fact, in this day and age, unchallenged for 40 years have been the dermatologists, telling you never to be exposed to direct Sunlight. Because if you ever did, (at least in the United States) you could wind up on “America’s Most Wanted” for child abuse, if you didn’t put your child outside without a sunscreen. And so, back in the 1930’s Harry Steenbock, from the University of Wisconsin, realized if you can irradiate people and animals to prevent Rickets, why not irradiate food, that lead to the Vitamin D fortification of milk, the eradication of Rickets, you don’t see Rickets commonly, so we’re not thinking of Vitamin D deficiency. But this is the problem: why is Vitamin D deficiency so common worldwide? Because humans have not appreciated that it’s been sunlight that’s provided us with our Vitamin D requirement. Why? Essentially no food contains enough Vitamin D to satisfy that requirement. Vitamin D is rare in naturally occurring foods and some fortified foods have so little, that you would have to eat a lot of it, in order to be able to become Vitamin D sufficient. In fact, we did a study many years ago and showed from the NHANES dataset that whether you’re a child or teenager, young, middle-aged or older adult, even if you accept that the Institute of Medicine’s recommendation of 600 Units of Vitamin D a day, essentially no one in the United States, even with dairy foods and orange juice fortified with Vitamin D, can you get enough from your diet. And so, as a result, you would have to drink 6 glasses of Vitamin D fortified milk (600 Units) a day, in order to get enough Vitamin D. Turns out that mushrooms, when exposed to sunlight or exposed to ultraviolet light, have a huge capacity to make Vitamin D and the Mushroom Industry now is exposing Portabella and White Button Mushrooms, to ultraviolet light. And so, you have about 400 Units in a serving. Also, Salmon, especially wild caught Salmon, have about 500-1000 Units in a serving. But as you can see, if you need at least 600-1000 Units of Vitamin D a day, which is what is recommended, by the Institute of Medicine, and the Endocrine Society, that you cannot easily get it from dietary sources.
So, when can you make Vitamin D, and where in your skin do you make Vitamin D? Well, it turns out that in the summertime, everybody knows when you’re exposed to Sunlight, you can make Vitamin D in your skin; but what about in the wintertime? We did a study, here in Boston, we also did a study in Canada, in fact we’ve done studies around the globe, to ask the question: “at what time of the year can you make Vitamin D?” It turns out, that if you live above Atlanta, GA, basically about 33 degrees North or 30 degrees South latitude on this planet, you basically cannot make any Vitamin D during the winter months. So, up here in Boston, for example, November through February, you cannot make any Vitamin D. Now, what about time of day? Well, it turns out that time of day is equally important; even in the summertime, in June at 8 o’clock in the morning, with the sun shining brightly, or at 6 o’clock in the afternoon, you will not make any Vitamin D in your skin. Most Vitamin D production occurs between about 10am and 3pm and before and after that, essentially, no Vitamin D is produced in your skin.
And so what are the issues about sunlight and the negative effects? There’s no question...excessive exposure to sunlight increases risk of Nonmelanoma skin cancer; easy to detect and easy to treat. For older adults, they worry about wrinkling, and so there’s an evolution in thinking about beachwear. In the 1950’s was two piece, in the 70’s was one piece, and in with new millennium, there is lots of clothing and a lot of sunscreen. So, if you put a sunscreen on with a sun protection factor of 30, it will absorb about 95-98% of the UVB radiation, that hits your skin. As a result, you reduce your ability to make Vitamin D in your skin, by about 95-98%. One of the issues and one of the questions that will be coming up will be ‘can you wash Vitamin D off of your skin, immediately after being exposed to sunlight”? The answer is “no”, and the reason is that the Vitamin D is produced in the living cells in your skin, mainly in your epidermis, so you cannot remove it from your skin. When you’re exposed to ultraviolet radiation, not only do you make Vitamin D in your skin, but you also make beta-endorphin. We’d showed many years ago, that when you are exposed to UVB radiation, keratinocytes (the epidermal skin cells), produce beta-endorphin and this may be one of the reasons why people feel better when they’re exposed to sunlight. New evidence has suggested that NO (nitrous oxide) is also being produced in the skin, and as you’re well aware, NO is a major regulator of controlling blood pressure. Some of the observations that were made, back in the late 1970’s, demonstrating that the higher the latitude that you live, the higher is your risk for having hypertension and we demonstrated that when you are exposed to tanning bed radiation, that your blood pressure dropped, and could in part, be due to the production of NO.
90-95% of your Vitamin D is still coming from casual exposure to sunlight. So, then the next question is: “how much do you want to be exposed to?” Well, I never encourage burning and certainly living in Boston, we don’t want to look like a red, cooked lobster. But what I do recommend is sensible sun exposure. What does that mean? Well, if you’re outside, in a bathing suit, on the beach and you get a light pinkness to your skin 24 hours later, is what we call a “minimal erythema dose”. That’s comparing it to, say, an oral dose of Vitamin D, it’s equivalent to about 15,000-20,000 Units of Vitamin D. So, you can see that your skin has a huge capacity to make Vitamin D. So, what about aging? We know that aging has a lot of effects on metabolic processes, and we went on to show that, indeed, if you are 70 years old and exposed to sunlight, you make about 25% of the Vitamin D that you would make if you were 20 years old. So, the obvious question is; “Can elders make any at all?” And we show, and others have shown the same, that if you take elders and expose them to a reasonable amount of sunlight, if they know they’re gonna get a mild sunburn, say after 30 minutes, I would have them exposed for about 10-15 minutes of arms, legs, abdomen and back, 2-3 times per week in the spring, summer and fall followed by good sun protection. And that’s a good recommendation for children, as well as young, middle aged, and older adults. No matter what your ethnicity, you can produce Vitamin D in your skin, and almost no matter what latitude, as well, and the study done in Denmark, showed very nicely, that the blood levels of 25 hydroxyvitamin D increased substantially. And so, we went on to show, that if you are of dark skin, a typical African American, most of the ultraviolet radiation that’s absorbed by the skin, and as a result, they reduce their ability to make Vitamin D in their skin by 5-10 fold, compared to a Caucasian. So, as a result, often African American’s are at much higher risk for Vitamin D deficiency and require to be outside for sometimes 3, 5, up to 10 times longer, to make enough Vitamin D.
And so we now know that Vitamin D deficiency not only will cause Rickets in children, but this painful bone disease, often misdiagnosed as fibromyalgia, called Osteomalacia. It improves muscle function, as well, as a result, improving your vitamin D status, both from increasing your dietary intake, Vitamin D supplementation and sensible sun exposure in the spring, summer and fall, can really guarantee good health, improved muscle function and give you a feeling of well-being. There are a couple of studies that are worth mentioning: the first is, as you well now know, that most cells in the body have a Vitamin D receptor. Why would they be there? As early as 1915, it was shown, that if you’re an indoor worker, in San Diego, you had an 8 times higher risk of dying of cancer, than if you lived outdoors. In the 1940’s, another study showed that those living in the Northeast were more likely to die of cancer, than if you lived down South, even if you were at a higher risk for getting skin cancer. The Garland Brothers began to show this interesting latitudinal association with increased risk for ovarian cancer, as well as colorectal cancer. And many studies have now shown that increasing your 25 hydroxyvitamin D levels, may reduce risk of many deadly cancers. One study done in Canada showed that women exposed to the most sunlight, during their teenage and young adult years, reduced their risk of getting breast cancer later in life by almost 70%.
So, what about the negatives? Certainly you worry about skin cancer, and as I said, often most skin cancers are non-melanoma, easy to detect and easy to treat. The most common, deadly skin cancer, however, is melanoma. It’s curious that most melanomas occur in the least sun exposed areas AND occupational sun exposure decreases risk. So, I think that my recommendation is clear, which is: that we should have a three-part strategy to improve our Vitamin D status and overall health and well-being. That is, to eat foods that are rich in Vitamin D when you can or when they’re supplemented with Vitamin D (to get a little bit Vitamin D), to definitely take advantage of the beneficial effect of sunlight, that is sensible sun exposure, and take a Vitamin D supplement.
The Endocrine Society recently recommended to prevent and treat Vitamin D deficiency, children should be on 600-1000 Units of Vitamin D a day and adults 1500-2000 Units of Vitamin D a day, and for those that are obese, you may need 2-3 times more Vitamin D, to satisfy that requirement. Finally, I’ll leave you with one last thought; a study was done in Australia, the skin capital of the world, and they looked at Vitamin D status in Australian dermatologists and guess what? 87% of dermatologists in Australia were found to be Vitamin D deficient, and so now the Australians are appreciating the beneficial effects of the sun, and beginning to recognize and to recommend sensible sun exposure for your health.
So, thank you very much for your kind attention and I’ll be happy to answer the questions that were provided to me, by Carol. Thank you.
Carole: How long does it take the vitamin D to be absorbed, and does washing with soap during this time remove the vitamin D? (Is there any validity to the claims that vitamin D can be washed out of the skin by common, every day soaps and skin cleansers?)
Dr. Holick: It’s a good question, it turns out that there is this misconception about vitamin D being absorbed; you make vitamin D in the living cells in your skin. Once it’s made, it’s released out of the cell and directly into your bloodstream. From my perspective, I don’t believe you could ever wash it off your skin, that’s really not an issue.
Carole: Is it better to obtain vitamin D from sunlight or to avoid UV exposure and take supplements? Does sunlight have benefits that go beyond simply creating more vitamin D?
Dr. Holick: It’s a very good question and I recommend that everybody take the supplement, because you can’t always guarantee that you’re going to get enough vitamin D from sun exposure, because we’re always working all the time. Like I said, you only make vitamin D from 10am, till about 3pm and only in the Spring, Summer and Fall…unless you live near the equator. Also, we know if you make vitamin D in your skin, it lasts 2-3 times longer in your body and we also know that when you’re exposed to sunlight, you feel better probably because you’re making beta-endorphin and there is some evidence that it may reduce blood pressure and that may be because of NO production.
Carole: In your book, “The Vitamin D Solution” you state that sunlight makes not only vitamin D but also at least five and up to ten additional photoproducts. What are these? What are their benefits to the body?
Dr. Holick: It’s a good question and we’re still on the hunt for many of them, we’ve identified them in skin and we’re beginning to find that they have some unique biologic properties and it could be one of them is to actually regulate cell growth and reduce risk of skin cancer.
Carole: What is the bioavailability of oral cholecalciferol from supplements in percent? Is it 100% bioavailable? Are vitamin D granules more bioavailable than tablet fomulations?
Dr. Holick: It’s a good question, I don’t think that we know what the percent bioavailability is but we’ve done studies with vitamin D3 in orange juice, in corn oil (placed on a piece of bread), in liquid form and in powder form (in a capsule) and for the most part, when we measure blood levels of vitamin D, 12-24 hours later, they are the same. So, we believe that for the most part, vitamin D in almost any formulation is equally bioavailable.
Carole: Do you think tanning beds are safe and a better way of getting vitamin D than supplements?
Dr. Holick: As you probably are aware, if you’ve read my book, I don’t advocate tanning but those that wish to do should do it responsibly. We did a study in tanners in Boston and we showed that tanners exposed to tanning bed just once per week, had robust, healthy levels of 25 hydroxyvitamin D and actually had higher bone density in their hip, compared to non-tanners, where their blood level, on average, was about 18 ng/ml in the winter time. So, for those that wish to get some vitamin D from a tanning bed, I typically recommend sun protection on your face because it’s the most sun exposed, most sun damaged and only go in for about 25-50% of the time recommended for tanning. Your skin will instantly make vitamin D and can supplement your vitamin D status.
Carole: Is the average over the counter vitamin D supplement made with healthy ingredients?
Dr. Holick: It depends on who is manufacturing it, for the most part, the major manufacturers, from my perspective, that the ingredients appear to be appropriate. I’m not sure what it means to be healthy but certainly they’re not harmful.
Carole: About the source of vitamin D: Is the vitamin D from fat wool (danger of prions) or from irradiated mushrooms better?
Dr. Holick: It’s a very good question it turns out, you don’t just simply get the vitamin D from fat wool, if you did, maybe you’d worry about this. What they actually do, is they collect cholesterol, it then goes through a chemical process, it then gets irradiated, and so there’s just no way that prions could be in any way related to the vitamin D that is produced from wool, from fat. Irradiated mushrooms do make vitamin D and can be an excellent source of vitamin D.
Carole: Are there any other nutrients that enable us to utilize the sun’s energy for our health?
Dr. Holick: It’s a very good question, what we know is that sunlight can certainly have an effect on folic acid and there is some suggestion that, possibly, that’s one of the reasons for skin pigmentation to have evolved but I’m not aware of any nutrients, per se, that are enhanced by the sun’s energy.
Carole: Are there any patient types for which we should be concerned about ABSORPTION of vitamin D3?
Dr. Holick: Yes, certainly patients with any kind of fat mal-absorption syndrome; inflammatory bowel disease (like Crones disease or ulcerative colitis) but also, we find, many patients we treat with vitamin D, often don’t raise their blood levels of 25 hydroxyvitamin D because they suffer from “silent celiac disease.” So often, we will evaluate patients for celiac disease and on occasion, we will find that the patient has celiac disease and can now better absorb the vitamin D. If you’re taking Cholestyramine to control your cholesterol level or any kind of drug that will absorb fat in your gut, to reduce risk for obesity, will also absorb vitamin D and so often, these patients should be taking the vitamin D separate from the Cholestyramine or these drugs that can inhibit fat absorption.
Carole: Is vitamin D synthesis reduced over age 60, and if so, how much additional exposure to the sun is required to produce the same amount of vitamin D as a younger person?
Dr. Holick: As I had mentioned, in my talk, is that as a 20 year old makes about 2-3 times more vitamin D in his or her skin, compared to a 60 or 70 year old. That doesn’t mean you should be outside longer, because the body only will permit you to make so much vitamin D and then you’ll begin to break it down. Instead what you’ll want to do is not have more exposure time, which will damage your skin, but rather expose larger surface area. More of your legs or more of your arms or abdomen and back if you wish to be able to make the amount of vitamin D that you desire. We did a study, in 70 year old men and women, and we demonstrated that putting them in our tanning bed, under ideal circumstances, for again, the amount of sunlight that would be about 50% of what would cause a light pinkness to your skin 24 hours later, we were able to raise their blood levels of into the 35-60 ng/ml range without difficulty. There’s also a product on the market called a “Sperti lamp”, that often can be valuable especially for patients with fat mal-absorption syndromes.
Carole: I am a man of 88, living in the UK, where we had almost no sunshine last summer. I take 12,000 IU of vitamin D per day and currently have a serum level of 59 ng/ml. As long as I remain with this amount of vitamin D in my blood, does it matter that I am not assimilating anything from the sunshine? I also noticed that in the previous summer, when I was able to sunbathe a little, my reading went down as I stopped supplementation and was relying solely on the sun.
Dr. Holick: It’s a good question, I mean, as far as we can tell right now, there doesn’t seem to be any difference from taking a vitamin D supplement, regarding your vitamin D status, versus being exposed to sunlight. But as the other questioner asked: what about those other photo-products, what about beta-endorphin, what about the production of NO? All of that you miss by not getting some sensible sun exposure. So, I do recommend sensible sun exposure, along with vitamin D supplementation and like I said, eating foods that either naturally contain or are supplemented with vitamin D.
Carole: Do you think it’s best to get sun at high noon when the UVB rays are stronger?
Dr. Holick: As it turns out, the answer is ‘yes’. Usually between 11- 1 o’clock in the afternoon, is the best time because you’re about 80-100% efficient in absorbing those UVB rays and producing vitamin D. If you’re exposed to sunlight at 8 o’clock in the morning, the sun is shining brightly, you’re not making any vitamin D in your skin, but you’re getting blasted actually by UVA radiation, which can increase risk for melanoma, as well as for skin wrinkling.
Carole: Fantastic! We are, for everyone’s information, going to be recording some more answers of Dr. Holick’s on a separate recording, which we will also post but our time is almost up, right now and I want to thank each and every one of you for attending and participating in these and to invite you to tune in next Tuesday at 10am again, with Dr. Carol Wagner (another one of our panelists). Dr. Wagner will be speaking to: “I already take vitamin D in my prenatal…do I need more? How safe is vitamin D in pregnancy?” I hope that you will attend and/or recommend others, whether or not you happen to be pregnant. Also, I wanted to invite any and all of you to join our Vitamin D action study, getting your test kits through Grassroots Health and as noted earlier, we will be sending a free vitamin D test kit and enrollment to our registrant #50, that came in on this. You’ll be interested to know that we had over 200 participants today, listening to you, Dr. Holick and thank you so very much, again, for sharing your information with us.