Adams: Today weíre speaking with Dr. Michael Holick, Thank you for
joining us today Dr. Holick.
Dr. Holick: Oh, itís my pleasure.
Adams: For those who may not be familiar with your work and your
website, can you give a brief introduction of what you cover and how
you got into it?
Dr. Holick: Sure, Iíve been doing research in the vitamin D field
for, now, more than 30 years, and I happened to be in the right
place at the right time as a graduate student at the University of
Wisconsin, and worked with one of the authorities in vitamin D, Dr.
As a graduate student my PhD project was actually the
isolation and identification of the active form of vitamin D, and my
roommate and I, over the next two years, were the first to
chemically synthesize it. And what was really neat about that
experience was that we actually gave this to patients when I was in
medical school - and patients that had bone diseases associated
with kidney failure, that were wheelchair bound, that had severe
bone pain started walking again.
That was my first introduction into one of the major benefits of
vitamin D and the development of it for the treatment of a
Adams: Does this mean you and your colleague were the first to
synthesize this form of vitamin D?
Dr. Holick: Yes, the active form of vitamin D thatís made by the
kidney, itís called
1,25-dihydroxy vitamin D.
Adams: Is this procedure more widely used now, for example to make
vitamin D supplements?
Dr. Holick: No, because this active form of vitamin D is available
only by prescription. Itís used to treat osteoporosis in Europe and
Japan. And itís also used to treat bone disease and kidney failure
patients, and has a lot of other uses as well.
Adams: So as you were doing the research on this, you were able to
immediately observe the health impact of it, right away.
Dr. Holick: Exactly, and what we began to realize was that vitamin D
was much more complex than thought.
We always knew that vitamin D
was made in your skin when you are exposed to sunlight, but it was
only in the 1970s that it was finally appreciated that it actually
had to go on this circuitous journey, first to your liver to get hydroxylated, kind of activated, modified
- whatís called
1,1,25-hydroxy vitamin D - itís the major circulating form of vitamin D
that doctors should be measuring in your blood to determine your
vitamin D status.
But that is also inactive, and it has to go to
your kidneys, and then in the kidneys it gets modified again, to its
active form, which we call 1,25-dihydroxy vitamin D. And itís this
125-dihydroxy vitamin D thatís responsible for telling your
intestines to absorb calcium from your diet more efficiently, and to
make sure that your blood calcium is normal and that you have
Adams: So if there is a failure of any of these body systems along
the chain, that can suppress the circulating active vitamin D then?
Dr. Holick: Exactly, and in fact if you have severe liver disease,
for example, you have two problems. One is that you may not be able
to modify it, to get the 1,1,25-hydroxy vitamin D, and secondly if you
have a fat malabsorption problem where you canít absorb dietary fat,
since vitamin D is a fat-soluble vitamin, then you canít absorb
vitamin D and you become deficient in vitamin D.
Then if you have
any kind of kidney disease, you need either activated vitamin D or
one its analogs in order to be able to maintain healthy bones.
Adams: In the testing then that you mentioned, was this active form
being given through injection?
Dr. Holick: You could either take it orally or by injections.
Adams: Interesting. So you mentioned the positive impact on people
who had trouble walking, who had osteoporosis, and various bone
diseases. What other effects did you observe?
Dr. Holick: We also realized a few years later was that your skin
doesnít only make vitamin D, which I think weíll talk about a little
bit more in a minute, but it also recognizes activated vitamin D.
And what was really, to me, quite amazing, was that in 1985 we
realized the possibility that if you take activated vitamin D and
put it in skin cells that you culture from humans, it turns out that
activated vitamin D was probably one of the most potent inhibitors
of skin cell growth.
So I reasoned back in 1985 that if that was
true, maybe you could take advantage of it by developing it to treat
the hyperproliferative skin disorder
psoriasis. And indeed itís one
of the treatments of choice now worldwide. Both activated vitamin D
and its analogs are used worldwide as the first line therapy for
And so again it shows you the breadth of activity that vitamin D
has. Not only just to regulate calcium metabolism and bone health,
but to regulate cell growth. And thatís why we started realizing
that people who live in higher latitudes and are more prone to
vitamin D deficiency and are more prone to developing common cancers
and dying of them, such as cancer of the colon, prostate, breast and
And we think that thatís in part due to the bodyís
inability to make enough activated vitamin D to help regulate cell
growth and to keep cell growth in check.
Adams: That would explain the links between breast cancer, prostate
cancer, colon cancer and vitamin D deficiency.
Dr. Holick: Exactly. And then the key factor that we found was that,
as I mentioned to you originally, we realized that the kidney was
the major source of the activation of vitamin D. And the function of
that is to make activated vitamin D for bone health. But we now also
know that the prostate, breast, colon and many other tissues in the
body can also activate vitamin D.
And by doing so, we think that it
locally produces this 1,25-dihydroxy vitamin D, which then
regulates cell growth. Itís a cell growth modulator. And I spell
all this out in my book ďThe
Adams: It seems like vitamin D is misnamed. Itís not really a
vitamin in the classic sense, is it?
Dr. Holick: Itís a good point, and the reason for it is as follows.
It was recognized in the mid-1800s that if you gave cod liver oil to
children who had rickets, it could cure rickets. And if you gave cod
liver oil to children without rickets, it prevented them from
getting rickets. So people thought that there was a vitamin present
that was necessary for bone health.
And that vitamin was finally
identified by taking cod liver oil and boiling it, because once you
boil cod liver oil, the vitamin A in it gets destroyed. Originally
they thought it was vitamin A that was responsible for bone health,
but when they boiled it and destroyed the vitamin A, the anti-ricketic
activity, that is the bone health activity, was still present in the
cod liver oil.
And so it was named vitamin D, because there had
already been identified a vitamin A, a B and a C, so the next in
line was vitamin D.
Adams: So this was many decades ago then?
Dr. Holick: This was back in the early 1900s. And then they realized
that if youíre exposed to sunlight, or artificial ultraviolet-B
radiation, that it also had anti-ricketic properties, i.e. that it
had bone health properties. So all of a sudden people began to
appreciate that the vitamin in cod liver oil was also being able to
be made by your skin.
And so youíre correct that it really is not a
vitamin, but itís a natural substance that we can make, but we can
only make it if we intelligently use sunlight for the purpose of
satisfying our bodyís requirements for vitamin D.
Adams: People donít typically think of their skin as being a
pharmaceutical factory, and itís a new concept for a lot of people.
Can you explain this point?
Dr. Holick: Yes, in fact the skin is the largest organ in your body,
and itís solely responsible for producing vitamin D and providing
the body with its vitamin D requirements. And youíre quite right
that itís basically a factory of all types of chemicals that are
being made in the skin, some of which probably alter body functions
And certainly one of them is vitamin D.
Adams: Iíve often heard vitamin D being described as a hormone. Is
that a valid description?
Dr. Holick: Well, hormone means itís made in one organ, goes into
the blood and has an effect on another organ system. And so if you
think about it, since vitamin D is made in the skin and gets into
your bloodstream and then goes into the liver and the kidney to get
activated, and then goes to the intestines and bones to have its
biological effects, by definition vitamin D is a hormone.
Adams: In your research on this, how common is vitamin D deficiency
in, say, the American population?
Dr. Holick: Whatís really remarkable is that vitamin D deficiency is
epidemic throughout the entire United States, through all age
groups. And Iíll give you some examples. Itís well known that elders
throughout the United States are at high risk. And upwards of 40-60%
are at risk for vitamin D deficiency.
But we also now realize that
even younger adults that are otherwise active and who may be always
wearing sunscreen before they go outdoors, or they never see the
light of day because theyíre working all the time.
When we did a
study in Boston, we found that students and doctors 18-29 years of
age, at the end of the winter, 32% were vitamin D deficient.
Dr. Holick: More shocking, though, was that we also looked at young
girls (working with Dr Sullivan and Dr Rosen in Maine)
- and these
are Caucasian girls ages 9-11 - and we found that 48% were vitamin D
deficient at the end of the winter. And 17% remained vitamin D
deficient at the end of the summer because of wearing all the sun
Adams: Now thatís even more shocking, itís obviously a chronic
Dr. Holick: But hereís even a bigger shock. I had been concerned,
and others had been concerned as well, that if youíre not exposed to
any sunlight or if you have very deep skin pigmentation, that you
need 1000 international units of vitamin D to satisfy your bodyís
requirements. And so we reasoned that probably women during
pregnancy, even though theyíre taking their prenatal vitamins that
contain 400 units of vitamin D, theyíre only getting 40% of what
So we did a study at our hospital, and we looked at women
coming in and giving birth, and we measured their vitamin D levels
- their 1,25-hydroxy vitamin D levels, and the infantsí 1,25-hydroxy
vitamin D levels at birth.
49 infant-mother pairs were looked at,
mostly African-American and Hispanic but some Caucasian as well. 76%
of mothers were severely vitamin D deficient. 81% of infants were
severely vitamin D deficient.
Adams: Thatís astonishing.
Dr. Holick: And so, what weíre now becoming more concerned about, me
and many of the experts, is that infants that are vitamin D
deficient at birth can remain vitamin D deficient for the first
several months after birth, it may put them at risk of developing
many chronic diseases later in life, including type 1 diabetes,
rheumatoid arthritis, multiple sclerosis, as well as many of the
common cancers of the breast, colon and prostate.
Adams: And this trend - can it be reversed through vitamin D
supplementation later on in their life? Or is that set in stone?
Dr. Holick: I donít know. What weíre concerned about is the
possibility that this may be imprint on the infant for the rest of
his/her life. And Iíll give you an example. There was a study done
in Finland, and what they did was they looked at children 1 year of
age that received 2000 units of vitamin D as a supplement for the
first several years, and they followed them for over 20 years.
when they compared their risk of getting type 1 diabetes as young
adults, they had an 80% reduced risk of developing type 1 diabetes.
Adams: Again, wow.
Dr. Holick: 80% decreased risk! And for children at 1 year of age
that were found to have rickets and were vitamin D deficient, they
had a fourfold increased risk of getting type-1 diabetes.
Adams: Was there any correlation with adult-onset diabetes as well,
or was that not studied?
Dr. Holick: Those studies have not been done, but what we do know is
that activated vitamin D does a couple of things. It will regulate
insulin secretion by your pancreas, which is of course one of the
major problems with type 2 diabetes, and it may increase insulin
We think that vitamin D deficiency may exacerbate type
2 diabetes, thereís some mounting evidence in the literature to
Adams: So, if I can summarize, it appears that we have a nation that
is suffering from chronic vitamin D deficiency that we are giving to
a whole new generation of children who are starting out deficient
and are therefore at a high risk for these diseases.
Dr. Holick: I think so, and thatís why weíre starting to sound the
alarm. Iíll give you another statistic. The CDC reported that when
they looked across the United States at African American women
during their child-bearing years, aged 15-49 years of age, 42% were
vitamin D deficient at the end of the winter time.
Adams: So why isnít this front page news, why arenít Americans being
warned right now to go out and get more vitamin D into their bodies?
Dr. Holick: Part of the problem, I believe is that people just take
vitamin D for granted. And in fact Iíve talked to many
dermatologists who blithely will say on TV that you just drink
another glass of milk, or you get vitamin D from your diet. And
unfortunately itís incorrect. They really are ignorant that very few
foods naturally contain vitamin D.
And weíre talking about oily fish
like salmon and mackerel, and you would have to eat salmon and
mackerel 3-5 times a week in order to get your vitamin D
requirement. Cod liver oil is another good source, although milk or
orange juice fortified with vitamin D has some, but there are only
100 units in an 8 oz glass of vitamin D-fortified milk and orange
So you would have to drink 10 glasses of milk or
10 glasses of
orange juice a day. You cannot get your vitamin D easily from your
diet. And even if you take a multivitamin, a multivitamin contains
400 international units of vitamin D, only 40% of what you need.
you would have to make a conscious effort to take a multivitamin,
drink 2 glasses of milk, drink a glass or two of orange juice
fortified with vitamin D and eat salmon to get the amount of vitamin
D that you require to satisfy your body.
Adams: Or you could just walk outside and get natural sunlight on
Dr. Holick: Or you can use sensible sun exposure, right. I mean, we
evolved in sunlight. We were bathed in sunlight, we feel better in
sunlight. And sunlight provides us with a gift, which is vitamin D.
And so, as youíre well aware, in my book, I have tables at the end
of the book, where I tell people anywhere on the globe, any time of
the year, for any skin type at any time of day, how long they can
stay outside to get some safe sun to provide them with their vitamin
D requirements, and then to use sun protection thereafter.
Adams: I think thatís wonderful that you have that kind of chart in
your book, because thatís what people are wondering. Can you give an
example, letís say someone of African descent living in the UK, for
Dr. Holick: Sure. If you were living in the UK, say in July, theyíre
much further north than we are in the U.S., about 10 degrees further
north in latitude, so the sunís rays are even weaker, so they
probably would need a good 30 to 60 minutes of exposure of arms and
legs, or hands face and arms, 2-3 times per week.
Adams: So thatís several hours a week they need to be getting.
Dr. Holick: Yes. But for a Caucasian it would probably be no more
than 5 to 10 minutes.
Adams: Also 2 or 3 times per week?
Dr. Holick: Yes, so it makes a big difference. A typical African
American with very deep skin pigmentation - they have sun
protection thatís typical of a sun protection factor of 15-30. And
what that means is that they can stay out 15-30 times longer. Which
means that they need to be out much longer to satisfy their bodyís
requirements of vitamin D.
Adams: Sure, that makes perfect sense.
Dr. Holick: And to give you an example of how powerful putting
sunscreen on is, if you put a sunscreen on with an SPF of 8, it
reduces your ability to make vitamin D in your skin by more than
Adams: So youíre pretty much shutting down vitamin D production with
even a mild sunscreen.
Dr. Holick: Exactly. And so what we recommend is you go outside for
5 or 10 minutes, enjoy the sun, make the vitamin D in your arms and
legs or hands face and arms, and then put the sunscreen on.
Adams: Right. That does sound sensible. Is there a direct
calculation where you can say X number of minutes under the sun at
this latitude equals a certain number of units of vitamin D?
Dr. Holick: Within reason. The problem is that obviously there are
clouds in the sky, and thereís pollution in the air including ozone
which absorbs the vitamin producing rays... but on average, I tell
my doctor friends that if youíre on the beach on Cape Cod, here in
Massachusetts in June, and you know that youíre going to get a mild
pinkness to your skin, say 30 minutes of being outside, in a bathing
suit, itís equivalent to taking 20,000 units of vitamin D orally.
Adams: OK, so thatís 20 times more than they might need.
Dr. Holick: Exactly. So what we recommend is that if you just expose
6-10% of your body, a couple of times a week, thatís all you need.
Adams: Another question then. Can, in addition to sunburn which is a
totally separate issue, can a personís body actually produce too
much vitamin D itself where it becomes toxic?
Dr. Holick: The answer is no. The body is very clever and no matter
how much sun youíre exposed to, you can never become intoxicated
with vitamin D. So if youíre a sun-worshipper or a lifeguard,
thereís never been a reported case of vitamin D toxicity.
reason is, as we had shown many years ago, that when youíre exposed
to sunlight, your body makes enough vitamin D, and that any excess
thatís made is destroyed by the sun.
Adams: So itís a self-regulating system, and thatís the best way to
Dr. Holick: Exactly. And basically it tells you that Mother Nature
really had always programmed for you to get your vitamin D
requirements from some sensible sun exposure.
Adams: What about storage of vitamin D in the body. If someone lives
in a climate where it gets cloudy for 2 months in a row, what then?
Dr. Holick: Excellent point. Remember I told you about the major
circulating form of vitamin D which is 1,25 hydroxy vitamin D? Itís
half-life in the blood stream is 2 weeks. So when you build up your
vitamin D levels during spring, summer and fall, you can use them
because your blood levels are much higher, and also some of the
vitamin D is stored in your body fat and is released during the
But the opposite is true also, and that is that if
youíre obese, we know that most obese people are prone to deficiency
in vitamin D, and the reason is that the vitamin D gets sucked into
the fat and it canít get out. And so we actually did a study in
obese and non-obese individuals, and we gave them either an oral
dose of vitamin D or we put them on our tanning beds so that they
can make vitamin D in their skin.
Obese people could only raise
their blood levels of vitamin D about half as much as non-obese
Adams: Very interesting.
Dr. Holick: And so if a person is in fact overweight, they donít
need 1000 units of vitamin D a day, they probably need 2000 units of
vitamin D a day.
Adams: Thatís fascinating, because again that plays into the
sensitivity to vitamin D, so thereís a vicious cycle going on there
Dr. Holick: Exactly.
Adams: Itís going to take a lot of vitamin D, a lot of sun exposure
to help break that cycle. Iíve got another question for you here. So
if a person has all the vitamin D that their body wants, and itís
stored in the fat tissues, how long can they go, is it a period of
Dr. Holick: Yeah, I mean if youíre getting a really adequate source
in the spring, summer and fall, itíll last two to three months. So
itíll get you through the winter. But for those that are concerned
about this issue, what I always tell my patients is, take a
multivitamin, youíre getting 400 units and get some sun exposure to
really make sure that youíre building up your stores of vitamin D.
And then during the wintertime especially take at least a
multivitamin, and maybe take an additional supplement, a vitamin D
supplement that contains another 400-1000 units of vitamin D.
Adams: Let me shift gears here and ask you about the controversy
side of this. Sadly, I think your book has been attacked with kind
of a surprising degree of ferocity. What has happened to you since
publishing this book and taking this stand on being a proponent of
Dr. Holick: Well, from my perspective, you know you have to look at
life and see that the glass is half full or half empty, and Iíve
always seen it as being half full. And I think that in many ways
itís been good.
Even though I was unfortunately fired from my
position in dermatology because my views on some sensible sun
exposure were counter to the American Academy of Dermatology and
some of the so-called leaders in the dermatology field, for the most
part I think that itís been a benefit because itís really raised the
publicís awareness about this issue and for that Iím really
Because in the past people have just said vitamin D,
ho-hum, sunshine vitamin ... who really cares about it? And these
people now have to take pause and begin to think about it.
Adams: And in the UK especially, theyíre now seeing an official body
overturning the advice to avoid the sun, isnít that right?
Dr. Holick: Which is wonderful.
Adams: But in the United States?
Dr. Holick: In the United States I think itís going to be a more
slow and gradual process, because the American Academy of
Dermatology has so brainwashed the public that you should never be
exposed to any sunlight, that it basically is part of everybodyís
way of life. And itís extremely unfortunate.
Adams: And it is widespread, wherever I go and talk to people, to
groups, I inevitably mention sunlight and vitamin D, and I have not
run into a single person yet that is aware of the health benefits of
ultraviolet radiation. Not a single one.
Dr. Holick: Iím not at all surprised. Like I said, the problem was
that over the past 20 years ago the dermatologists have basically
been in control of the media regarding the role of sunlight in
health. And all theyíve looked at is the negative effect.
thereís no question that chronic, excessive exposure to sunlight
increases risk of non-melanoma skin cancer, which is Basal or
Squamous cell cancer. I make that very clear in my book.
Dr. Holick: But thereís very little evidence in my opinion that
sensible, moderate sun exposure increases your risk of the most
deadly form of skin cancer, melanoma. In fact, thereís good evidence
to suggest that it may decrease your risk.
Adams: What about sunscreen products? The sunscreen manufacturers, I
think theyíre happy to go along with the idea that sun should be
avoided. Whatís been your experience?
Dr. Holick: Yeah, I think that thereís no question that the
Academy of Dermatology is well-funded by the
sunscreen industry, and
Iím sure that that plays a role in this.
Adams: Thereís influence, or lobbying, or what?
Dr. Holick: Well, back in April, just before my book was launched, I
think the ďSafe Skin AssociationĒ actually put out a paid news
release attacking me and the book, even before it was launched.
Adams: You really have to be stirring things up to get that kind of
Dr. Holick: Yeah. It was called the ďSafe Skin AllianceĒ I believe.
And it was actually funded by one of the companies that makes
Coppertone, among other sunscreen products.
Adams: And just to be clear to the readers or listeners here, your
advice to get sensible exposure to the sun, technically doesnít
preclude using sunscreens in an intelligent way. Correct?
Dr. Holick: Correct. In fact, thatís what I make very clear in the
book, is, go out for the 5-10 minutes, be exposed to sensible sun
exposure, then put a sunscreen on with the proper SPF. And I even
teach you in the book how much sunscreen to use to make sure that
youíre getting the full sun protection thatís stated on the bottle.
Adams: Letís move on to discuss some of the other disorders or
diseases that are correlated with vitamin D deficiency. Letís talk
about mental health and Seasonal Affective Disorder.
Dr. Holick: Principally,
Seasonal Affective Disorder is due to the
fact that people who live in northern climates canít easily regulate
the production of
melatonin by the pineal gland. And melatonin is a
hormone that causes you to fall asleep basically, or to hibernate.
And so for many people that live in northern latitudes, the sunís
rays are not intense enough and long enough in exposure time to
regulate melatonin levels.
So people will wake up in the morning in
winter time, their melatonin levels are not suppressed as they
should be if youíre exposed to some bright sunlight, and as a result
they feel tired and they want to hibernate throughout the winter.
They get depressed.
There is one study, however, that looked at patients with seasonal
affective disorder and looked at exposing them to a tanning bed, and
looking at their vitamin D levels, and they could show a direct
benefit from increasing blood levels of 1,25-hydroxy vitamin D and
relief of symptoms of seasonal affective disorder.
We also know that
people during the winter time have aches and pains in their bones
and muscles, and it also makes them depressed. And we now recognize
that vitamin D is very important for muscle function, and that
people who are vitamin D deficient are prone to have muscle
weakness, theyíre more likely to fall and theyíre more likely to
have bone fractures.
We also know that if youíre vitamin D
deficient, not only does it precipitate and exacerbate osteoporosis
in older men and women, but it causes a very subtle and quite
devastating bone disease known as
Long story short, osteomalatia is like adult rickets. And what it does is it causes
severe bone discomfort, achiness in the bones and also in the
muscles. And these patients are often misdiagnosed as having
Adams: Yes, that makes sense.
Dr. Holick: There was a study done in Minnesota by Dr
what he showed was that, he looked at over 150 individuals. And
weíre talking about children ages 10+ and adults up to the age of
65, presenting at a Minnesota hospital in the wintertime,
complaining of muscle aches and pains and bone pain.
Many of these,
especially young women in their 20s, were given Motrin or some type
of over the counter drug, or even a prescription strength
anti-inflammatory drug (NSAIDs) because the doctors couldnít figure
out what was going on.
93% of that entire group of children and
adults complaining of bone pain or muscle pain were vitamin D
Dr. Holick: And none of the doctors at the time recognized the signs
and symptoms or worked these people up for vitamin D deficiency, or
treated them appropriately.
Adams: What a tragic failure of diagnosis and treatment.
Dr. Holick: I see this all the time in my clinic. I see women as
well as men coming in complaining of severe achiness in their bones
and muscles. A complete work up, sometimes thousands of dollars are
spent, to do all kinds of tests, not to find the cause, only to be
seen by me, only to find that theyíre vitamin D deficient.
explained, it takes months, it takes years to become vitamin D
deficient, and to have such problems with your bones and muscles,
and it takes months at least if not up to a year of intensive
vitamin D treatment and sunlight exposure in order to reverse that
Adams: Thatís an important bit of information: youíre saying months
to years to reverse the deficiency?
Dr. Holick: Right, but what I also tell my patients is that theyíll
begin to feel better after a month or two, but itís not something
thatís going to happen overnight. And I have one particular case of
a woman who was hospitalized, totally immobile and was just
complaining of global bone pain and muscle aches and weakness ...
she couldnít even get out of bed! And her doctors didnít know what
to do with her.
She basically was admitted to the hospital to die.
And I happened to see her because I was on call for that weekend,
and I instantly recognized it - she was African American, she was
not outside at all. I was convinced based on my physical exam.
Typically what I like to do is if you take your forefinger and press
on the breastbone a little bit, if the patient winces in pain, itís
consistent with osteomalatia.
And thatís exactly what she did. She
was excruciatingly uncomfortable with minimum touching of her
sternum. I was convinced that she had osteomalatia. And I told her,
I want you out of the hospital. Iím giving you vitamin D, and Iím
telling you to go out and be exposed to some sunlight, and youíre
going to start feeling better in a month or two. Hopefully youíll
get in your wheelchair, and then eventually youíll be able to walk
within six months.
And then sure enough, I just saw her in clinic
this past Monday, and she now is up and walking around, using a
walker. Really almost for the first time in half a dozen years.
Adams: Fascinating. How many other people are in nursing homes and
hospitals right now suffering from nothing more complicated than
Dr. Holick: I saw another case in my clinic on Monday, which was
absolutely shocking, which again shows how pervasive this concept is
that the American Academy of Dermatology has provided to the media.
I saw a 45 year old woman who brought in her 7 year old son, and her
son had severe
rickets. Sheís Caucasian, as is her son and the
And she was told, because she was older when she had her
first pregnancy that she was at very high risk of having a potential
problem, that she should never be exposed to any sunlight.
Dr. Holick: And so she followed her physicianís advice. And then she
was told that when she gives birth, that she should solely
breastfeed her infant, and that the infant should not receive any
extra outside nutrition or supplements. And she followed the
Adams: And passed on the vitamin D deficiency.
Dr. Holick: By this age, the child had severe bowing of the legs,
and thatís severe rickets.
Adams: Fascinating. And it seems like, well, what do you estimate
--how many people are in nursing homes and hospitals right now with
this condition, and those buildings are typically windowless...
Dr. Holick: Doesnít matter actually, because vitamin D rays are
absorbed by the glass, so even if youíre exposed to sunlight through
glass, you canít make any vitamin D.
Adams: And thatís all glass?
Dr. Holick: All glass. And so if youíre driving in the car all the
time, itís not going to do you any good. But the bottom line is this
- a study was done in Mass General Hospital. They found over 50% of
inpatients - these are young adults, and middle aged, and older
adults - were vitamin D deficient.
Typically, on average, probably
50-80% of nursing home residents, 50-60% of inpatient hospital
patients, and on average I would estimate, 40% of the population in
the United States at large, if theyíre not getting some sensible sun
exposure, are probably deficient in vitamin D.
A study was done in
Mass General Hospital. They found
over 50% of inpatients - these are young adults, and middle aged,
and older adults - were vitamin D deficient.
Typically, on average,
probably 50-80% of nursing home residents, 50-60% of inpatient
hospital patients, and on average I would estimate, 40% of the
population in the United States at large, if theyíre not getting
some sensible sun exposure, are probably deficient in vitamin D.
Adams: And let me bring you back to the mental effects of this.
Whatís the correlation - beyond depression, are there other areas?
Dr. Holick: Well, thereís a fellow in Australia thatís done a very
interesting study. And what heís concluded is the possibility that
if youíre born during the wintertime, youíre at higher risk of
developing schizophrenia later in life. And during the wintertime
youíre more prone to vitamin D deficiency.
And heís done studies in
mice to show that vitamin D seems to be critically important for the
development of the brain. So there is some suggestive evidence that
maybe indeed vitamin D deficiency, especially in utero as well as in
infancy could potentially increase that individualís risk of
developing schizophrenia later in life.
Adams: Fascinating. So hereís another question then. If sunlight
could be bottled up and put in capsules and patented by
pharmaceutical companies, how much would they charge for it?
Dr. Holick: Well, vitamin D is available pharmaceutically. And itís
shocking but true that theyíre charging about $10 per pill for my
Adams: $10 per pill?
Dr. Holick: Yes.
Adams: And thatís for 1000 units?
Dr. Holick: No, thatís for 50,000 units. I typically treat my
patients with 50,000 units of vitamin D once a week for 8 weeks,
followed by 50,000 units of vitamin D every other week. And thatís a
great way to fill up the vitamin D tank if itís empty, and to
maintain it in its full state for the patient for the rest of his or
Adams: Do you think part of the reason the health benefits of
natural sunlight arenít getting a lot of attention is because
thereís no money in it? I mean, sunshineís free.
Dr. Holick: It certainly is a part of it. And like I said, the
problem is that vitamin D deficiency has such subtle but incredibly
important health implications. Itís the subtlety thatís the problem.
I mean, when you mention the word cancer, everybodyís aware of that,
and everybodyís aware of how serious cancer is. And so people will
immediately help fund that kind of research, and promote that kind
But to suggest that sensible sun exposure, making vitamin D, vitamin
D probably evolved early in evolution to modulate cell growth,
decrease risk of cancer, modulate your kidney to produce the blood
renin, which regulates your blood pressure ... I
mean all of those things are very subtle, you canít feel your blood
pressure, and you canít feel your cells growing, but you certainly
know if you have cancer.
By then itís too late, what you really want
to do is take preventative measures, and one of those is to make
sure youíre getting an adequate source of vitamin D, both from
vitamin supplements and from sensible sun exposure.
Adams: In your book you talk about the link with
calcium and calcium
assimilation. How important is that for people to understand?
Dr. Holick: Well, itís critically important for people to realize
that even if they have an adequate amount of vitamin D, if they
donít have any calcium around, the vitamin D canít have the desired
effect on bone health without being able to get enough calcium out
of the diet and to put it into the bloodstream which will eventually
get to your bones.
So, making sure that you have adequate calcium
intake is very important.
And the recommendation by the Institute of
Medicine (and I was on this committee back in 1997) is that if
youíre a teenager, 1300mg a day of calcium, for adults ages 18-50
itís 1000mg of calcium and 51+ years itís 1200mgs of calcium for
both men and women.
Adams: And you mention that you have to have calcium in your system
for vitamin D to work -is the opposite also true? Youíve got to have
vitamin D for the calcium to be effective?
Dr. Holick: Oh, no question about it. If you are deficient in
vitamin D, you absorb on average 10-15% of the calcium thatís in
your diet. If youíre sufficient in vitamin D, if you have adequate
sun exposure or adequate intake of vitamin D, you absorb about 30%
of the calcium in your diet. During pregnancy and lactation, and
during growth spurts, the body responds appropriately by actually
increasing that efficiency up to 80%.
Adams: So the normal level is 30%.
Dr. Holick: 30% for healthy adults, yes.
Adams: So a person whoís taking, letís say coral calcium
supplements, if theyíre not getting sunshine or vitamin D to go with
it, their absorption is halved.
Dr. Holick: Yeah, exactly, and itís really of little benefit.
Adams: Thatís fascinating. Once again showing that thereís no single
magic pill, you have to be healthy across the board.
Dr. Holick: Thatís right. And what I typically recommend to my
patients is Tums or Os-Cal or Caltrate or any of the respected
brands... Super Cal or all good sources of calcium.
Adams: As long as youíve got vitamin D.
Dr. Holick: Correct. If you have adequate vitamin D or some sun
Adams: Cod liver oil is of course a great source of vitamin D, as
you mention, but some people are concerned about contamination of
these oily fish with heavy metals - is that a concern?
Dr. Holick: Yes, PCBs. And so, what you have to do is if youíre
going to buy it, buy it from a respectable source. Certainly itís a
step in the right direction. But you know there are omega fatty
acids in there that have benefits to the heart, and have other
health benefits. So it may be that many of those outweigh the
possible risk if there are contaminants in there.
Although, like I
said, a lot of the manufacturers are pretty good at making sure that
Adams: How do you think our country would look in terms of
healthcare costs or patient counts if every person were out there
getting sensible sunlight and getting adequate vitamin D? What would
Dr. Holick: Itís almost incalculable, because like I said if you
just think about the study that was done in Finland where it can
reduce your risk of getting type 1 diabetes by 80%. Studies that
have been done in the United States and Europe show it can decrease
risk of getting colon cancer and dying of colon cancer by 50%,
prostate cancer by 50%, ovarian cancer and breast cancer by almost
the same amount.
The amount of not only money saved, but the amount
of grief and pain and suffering that people go through with these
serious chronic diseases, potentially could be avoided.
Adams: And are these all topics that you discuss in more detail in
the UV advantage book?
Dr. Holick: Thatís correct. Not only do I discuss these topics and I
think in a relatively simple, readable form, but for those that are
interested in going to the source, I provide almost 100 references,
scientific references for almost everything that I say in the book.
So everything that I say in the book is well documented by good
Adams: I find that fascinating. And yet, it remains controversial in
so many circles. It just seems like those old beliefs are hard to
Dr. Holick: Itís really quite remarkable. And like I said, it was a
big surprise to me, because I would have thought, and in fact I was
a little bit surprised because in the beginning of the book you know
that I specifically state that I do not advocate tanning. However, I
also point out that for those that wish to tan, they should do it
And that in fact is the message in the book, that you
should take advantage of some sensible sun exposure for your health.
Itís incredibly important, not only for your bone health, but for
the prevention of many serious, chronic diseases. And the parents
out there should really think about their children.
Because I know
that theyíre so concerned about their children, they always put a
sunscreen on. And I know even from my own experience in my clinical
office that African American mothers are so worried about this
message that any sun exposure could increase the risk of skin
cancer, that they even put sunscreen on their children.
And as a
result they even put them at a higher risk of developing vitamin D
Adams: They might as well put on a suit of armor!
Dr. Holick: Thatís exactly right. And itís so unfortunate. And itís
probably not atypical of the kind of American psyche - that very
seldom do they practice moderation, they always like the extremes.
And so this is a very unfortunate extreme, to suggest that people
should never be exposed to direct sunlight.
In my opinion, itís
really bad advice.
Adams: Have you thought about marketing a product, a watch that you
can wear that senses UV radiation and tells people when they have
sufficient amounts? Because they have ones that warn people about
overexposure, but not ones that tell people how much sunlight they
Dr. Holick: Weíve thought about that, and weíve developed a method
where we can tell you how much vitamin D youíre making, but itís
somewhat cumbersome, and itís probably going to take a lot more
effort before such a product could potentially be available.
Adams: I certainly hope you find cause to pursue that, because I
think that would be a great aid to people. Thereís a big question
mark when people go outside - they donít know how much time... is
it too much, is it too little? They need something they can look at,
that will give them some guidance.
I think that would be a popular
product as the public opinion shifts on this issue.
Dr. Holick: Well, there may be some inventive individuals out there
listening right now. It may spark their interest.
Adams: Weíll call it the ďHealthy Sun WatchĒ or something. Of course
youíd have to enter your skin pigmentation into the device, right?
Dr. Holick: Sure. Yep.
Adams: And your latitude even? Is that true?
Dr. Holick: You could
put your latitude, time of day, season of the year, you could
program it all probably into a little mini-computer.
Adams: I hope to see something like that. Final question for you, Dr
Holick. Whatís next on the horizon for you? Any other upcoming projects youíd like to mention?
Well, weíre very interested now in taking the vitamin D story in
cancer to the next level. Weíre in the process of demonstrating
clearly in animal models that if youíre deficient in vitamin D that
it will not only cause colon cancer to be more aggressive but that
the tumor will continue to grow in a very significant way.
also are now working on developing analogs of activated vitamin D
specifically to treat colon, prostate and breast cancer.
Adams: These would be oral supplements?
Dr. Holick: These would be,
not supplements, but oral drugs.
Adams: OK, so these would be by
prescription only. But theyíre molecularly identical to the
activated vitamin D in your body?
Dr. Holick: Exactly, but would be more
potent than the activated vitamin D.
Adams: Do you have a practice
where people can visit you long distance? I mean, they can come visit you?
Dr. Holick: Yeah, I have a lot of people from around the globe that
will make an appointment and see me. And Iím certainly happy to do
Adams: What city are you located in?
Dr. Holick: In Boston. In
the University Medical Center.
Adams: OK, Boston, so not exactly the
sunlight capital of the world there, either, but for those who are looking to go right to the top here, to work with the expert, can
they contact you at uvadvantage.com?
Dr. Holick: Itís probably difficult to do that, but I think what
they could do is probably to get in touch with you and I can give
you some of that information.
Adams: OK, that sounds great, Iíll be
happy to pass on the contact information for anyone who emails us and wants to come visit you. So weíve been talking today with Dr
Michael Holick, author of ďThe
UV advantage,Ē who as you can see
here, is an authority on vitamin D, the best-informed person Iíve
ever spoken with on this subject. And I want to thank you very much
for your time today, Dr Holick.
Dr. Holick: My pleasure, and - enjoy the sun!