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Vitamin D

Friday, November 26th, 2010

Ever since doing Snake Oil visualization, I’ve become a little obsessed with optimising my diet. Hey – what else is there to do on a winter evening? Strange thing. Vitamin D keeps popping up in all kinds of research. Evidence seems to be growing for its extensive potential role in health, cancer prevention and even mental health and mood.


Deficiency may even be a contributing factor for the greater prevalence of heart disease and diabetes among African-Americans (dark-skinned peoples have much more difficulty synthesising vitamin D from sunlight). Nearly 100% African Americans could have insufficient Vitamin D, according to some studies. Nearly 1 in 3 could be severely deficient.

I got curious. And inevitably that curiosity spawned a yomming great infographic.

See the image on its own

UPDATED! Data and research: http://bit.ly/42degreesN

Vitamin D



UPDATE: 1st Dec. The US Institute of Medicine have released an equally yomming report on Vitamin D. (Story in NY Times | Original PDF report) It does a lot of cross- and meta-analysis on the various studies out there. Some findings contradict what I’ve visualized here. So I’ve folded in the new info and adapted the visuals. You can see a detailed summary in the Change Log. The headlines are: 

  • Evidence for health benefits beyond bone health are “inconsistent & conflicting” – I’ve changed wording
  • Blood levels that count as ‘insufficient’ vitamin D are disputed and unstandardized – I’ve added a note
  • The Recommended Daily Allowance has been boosted to 600 IU, from 200 IUs – I’ve added this

Everything else seems to stand up! I’ve updated the data spreadsheet too.

(The report doesn’t mention latitudes or UVB exposure. So I’m sticking to my 2000IUs vegicaps a day during the winter)

If you find any other research, please send it over or post below.


Spanish translation – thanks to Alex


 

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Show Comments ( )

  • elise

    question: how long have you been taking vitamin d supplements and have you noticed any benefits?

    • http://ordblogg.wordpress.com Klara

      Actually it doesn’t take that long, about a week. At least that is what I find when I forget to buy my cod-liver oil in October, I can’t say for other supplements. I live in Norway, and since it tends to be rainy and not snowy where I live, it is *dark*.

    • allan Tramley
      • david

        Thanks Allan and to everyone who sent this. I will fold this new info into the diagram.

    • Sylvia

      I have been taking 50,000 IU Vitamin D once a month (1 pill) prescribed by doctor for about one year. It has made a world of difference for me. No more muscle aches, bones are not as stiff, no more depression. I am not irritable any more. Thanks to my doctor!!!

    • james gould

      what is the best food scource of vitiman d

  • Le dude

    Cool. I’m always skeptical about all these dietary requirements, and how 2 glasses of wine are good for you but 1,5 glasses increase breast cancer risk and what else (read http://www.theatlantic.com/magazine/archive/2010/11/lies-damned-lies-and-medical-science/8269/ to get an idea of the uselessness). Still, on Vit. D: last year became a dad in winter, very tiring, etc. and come spring I felt depleted of all energy, ultra-moody, and I kept getting sick. Blood checked: all normal… except Vit. D, which was severely deficient. So I started swallowing that D, and lo and behold: Lazarus lived! A friend working in endocrinology later told me that all doctors are heftily downing D during the winter. So there, the rest is just up for oneself to test.

  • Tim

    But there’s enough light below 42 degrees south. :-P

    Also this graphic has tons of sharp lines that should be blurry, e.g. 42 degrees, the line between UVA and UVB (they are arbitrary frequency ranges).

    • AC

      I would guess that there wouldn’t be any issue in the southern hemisphere Nov-Feb. Maybe Jun-Aug, though.

      • Mark C

        Yes, I came to point that oversight—summer in the Northern Hemisphere is winter in the Southern. There is nothing special that prevents this from happening in the south.

        • david

          Thanks for pointing this out. Can you route me to a source on this, as I have a cited source for insufficient UVB above 42N but nothing for the southern

        • Nicole

          Well I don’t have a source, but I live in Cape Town, South Africa (pretty much the southern tip of Africa). Even though we have winter rain it isn’t nearly as bad as the winters in Europe… There are usually a few sunny days a week. :) Best weather in the world ;)

        • http://www.twitter.com/aprilsun April Sun

          Here are a few links:
          The average UVI levels for Australia from the Australian Radiation Protection Agency: http://bit.ly/gm9PCj
          Kingston is 43S and has a UVI below 3 from May to August.

          The average UVI levels for New Zealand from the Cancer Society website but the data is based on information from the National Institute of Water and Atmospheric Research: http://bit.ly/hbWF8g
          Wellington is 41S and has a UVI below 3 from May to September.

    • Christine

      I think it may just be that the penguins have different vitamin D requirements. There’s a lot more people living above the 42nd parallel N than below the 42nd parellel south.

      • http://blog.meteorit.co.uk AdamV

        Of course – penguins are probably eating plenty of oily fish already!

  • Jacqui Taylor

    Hi David

    This is awesome. I had been aware it was an issue, but wasn’t aware of how much impact a deficiency could mean. Thanks also for including the dosage you take. As a trip to the caribbean is out this winter I guess next stop, the health food shop.

    Jacqui

  • Sheila

    Thank you for the information about Vitamin D. Check the facts about MS and Vitamin D, too. Good information.

  • baztastic

    I live in Ireland and was wondering about exactly this recently, thanks! It’s gotten much colder here in the last few weeks (might snow tonight), which means the only part of my body usually exposed to what little light we do get is my face, which hardly seems like much in the way of vitamin D generation, may start taking supplements so!

  • http://not-a-foodblog.blogspot.com Vincci

    Beautiful! Loved the distinction that UVA “ages skin” and UVB “burns”

    As a dietitian, I would just like to let you know that most would not recommend cod liver oil as a source of vitamin D as it is a very rich source of vitamin A. Vitamin A supplementation is usually not recommended for people as it increases the risk for toxicity. Too much vitamin A has been shown to increase the risk of birth defects in pregnant women, and the risk of liver damage in the general population.

    • Tracey

      This is only true of *artificially-produced vitamin A*, which has half the molecules mirror images of the others. The body can only use one kind and the other is toxic. If you’re getting artificial vitamin A in your diet you should not take cod liver oil.

      I’d much rather forgo processed food with its artificially-produced, toxic fat-soluble vitamins in favor of real foods like cod liver oil.

      • Bryan

        One can ingest toxic levels of vit A from natural sources. Polar bear liver is an example.

        • david

          That’s a joke, right?

        • chris f

          not a joke.. 3 grams of polar bear liver can kill you!

    • lisa

      Is a perfect example of flawed dietary advice from so called “experts”. Please look past CW and look at natural sources vs. synthetic, benefits of vitamin D and A ratios, as examples.

  • http://voluptuousvegetarian.blogspot.com Stacey

    I always enjoy the graphic representations of information at ‘informationisbeautiful.net.
    I too am interested in optimizing diet, and am always doing research. In my research I have come across the possibility that there is an important differentiation between vitamin D2 and vitamin D3, which I thought I’d mention. Some sites (such as mercola.com) which stress vitamin D3 as the muchly preferable source of vitamin D. Any thoughts? best wishes :)

  • http://crabsalloverhealth.blogspot.com/ crabsallover

    Food Standards Agency advice is that ‘Most people should be able to get the amount of Vitamin D they need by eating a varied and balanced diet and by getting some sun. But if you decide to take vitamin D supplements it’s a good idea not to take too much because this could be harmful.Taking 25 micrograms (0.025 mg) or less of vitamin D supplements a day is unlikely to cause any harm.
    source: http://eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/vitamind/
    info: http://www.food.gov.uk/multimedia/pdfs/evm_d.pdf
    10 micrograms = 400IU

    • Michael Blackburn

      The Food Standards Agency is incorrect and is at odds with most other similar agencies in the ‘civilised’ world. In the UK, you cannot obtain enough vitamin D in food, unless you are prepared to eat vast quantities of ceratin foods. It is now recognised that it is impossible to overdose on vitamin D, as the body has a whole gamut of self-regulatory functions that prevent this. May I suggest that you read this?

      http://www.healthresearchforum.org.uk/reports.html

    • http://blog.meteorit.co.uk AdamV

      In the UK various foods are required by law to include additional vitamin D, including bread products, so this would seem to be at odds with the FSA claim that you would get this through a normal varied diet.Why would they need to mandate it being added if that were the case? Or maybe it is only true because of the products which have it added to them, in a self-proving sort of way.

      As far as I know, most margarine also has vitamin D added, but whether this is to bring it up to similar levels as butter or even higher, I’m not sure. I know it can be an annoyance for vegans since the source of this vitamin D is often lanolin, so this rules out many marge products for them.

      (Aside: This is why most automatic bread makers have recipes which include dried milk powder, which also has vit D added, to make sure that people who switch from commercial bread don’t get less than they are used without realising why.)

  • Bartek Ciszkowski

    Lovely infographic .. Kind of concerning that the National Institute of Health recommends margarine for Vitamin D. Sure, it contains it — But everyone knows how horribly bad it is for you.

    • david

      yeah I wondered that too.

    • Bryan

      Many people eat margarine, so at least they know it’s a good source of Vit D.

  • TK

    1/3 of African Americans have vitamin D deficiency because KFC doesn’t supply much of it.

    • Sam

      Racist jerk is a racist jerk.

    • Kate Mack

      The above comment by TK adds nothing to this discussion.

  • Andy

    Wonderful series of maps and charts. However, the 42 deg line in the global map is wrong. It’s shown too far south. Barcelona, Naples and Istanbul, for example, are all around 41 degrees north yet clearly lie north of the line in the map. (Adding the Great Lakes to North America would also help immeasurably for a reference point since the 42d parallel runs through them.)

    • david

      thanks Andy. I will try to fix.

  • David

    Also, Vitamin D supplements during the early life reduces the risk of later developing schizophrenia in males (McGrath et al., 2004).

  • http://www.VitaminDWiki.com Henry Lahore

    I do not know which is better: McCandless or Vitamin D
    Here is a web page with the current vitamin D graphic and a link to various verisions of his Snake Oil graphic
    http://www.vitamindwiki.com/tiki-index.php?page_id=1188
    http://www.vitamindwiki.com/ has over 2500 items on vitamin D divided into 62 categories -

  • http://thuchuynh.com thuc huynh

    awesome. love your work.

  • http://adamchavez.net Adam

    Quick note on the above. It is extremely important to not take cod liver oil as your vitamin D source. The problem with cod liver oil is that it contains toxic levels of vitamin A, which acts as an antagonist against vitamin D. They use the same receptor and so when there is too much vitamin A in the blood, even moderate toxicity, the good effects of vitamin D will be greatly diminished.

    Also, if you are going to take a multivitamin, make sure it is 100% beta carotene, as other forms of vitamin A (eg. retinol, the kind of vitamin A that cod liver oil contains) cannot be flushed out of the system and will lead to toxicity. Below is a more thorough analysis by Dr. John Cannell.

    “Although activated vitamin D and vitamin A signal through common cofactors, they compete for each others function. Retinoic acid antagonizes the action of vitamin D and its active metabolite. In humans, even the vitamin A in a single serving of liver impairs vitamin D’s rapid intestinal calcium response. In a dietary intake study, Oh, et al, found that a high retinol intake completely thwarted vitamin D’s otherwise protective effect on distal colorectal adenoma, and they found a clear relationship between vitamin D and vitamin A intakes, as the women in the highest quintile of vitamin D intake also ingested around 10,000 IU/d of retinol.” [1a, 1b, 1c]

    “Furthermore, the consumption of preformed retinol even in amounts consumed by many Americans in both multivitamins and cod liver oil may cause bone toxicity in individuals with inadequate vitamin D status. Women in the highest quintile of total vitamin A intake have a 1.5-times elevated risk of hip fracture.” [2]

    “Indeed, a recent Cochrane Review found that vitamin A supplements increased total mortality rate by 16%, perhaps through antagonism of vitamin D.” [3]

    “Another recent Cochrane meta-analysis concluded that although vitamin A significantly reduced the incidence of acute lower respiratory tract infections in children with low intake of retinol, as occurs in the Third World, it appears to increase the risk and/or worsen the clinical course in children in developed countries.” [4]

    “As early as 1933, Alfred Hess, who discovered that sunlight both prevented and cured rickets warned about vitamin A consumption, concluding, …as to a requirement of thousands of units of vitamin A daily, the unquestionable answer is that this constitutes therapeutic absurdity, which, happily, will prove to be only a passing fad (p 662).”

    “Unfortunately, Hess’s prophecy of a passing fad proved premature and Americans continue consuming multivitamins and/or cod liver oil containing small amounts of vitamin D but undesirable quantities of vitamin A. For example, multivitamins, until recently, had small amounts of vitamin D (200 to 400 IU) but high amounts of preformed retinol (5,000 to 10,000 IU). This pales in comparison to a tablespoon of modern cod liver oil, most of which contains sub-physiological amounts of vitamin D (400 to 1200 IU) but supra-physiological amounts of completely preformed retinol (5,000 to 15,000 IU or, in some cases, 30,000 IU).” [5, 6]

    “Clinical lore holds that Vitamin A is an anti-infective. We suggest that lore exists because of old cod liver oil studies. Semba reviewed early literature on vitamin A, usually given as cod or halibut liver oil, as a successful anti-infective. For reasons that are not entirely clear, fish liver oils of the time contained much higher amounts of vitamin D then does modern cod liver oil, perhaps because modern processing removes the vitamin D during distillation and then replace it at lower doses. Furthermore, a meta-analysis concluded that vitamin A, when given alone, increases the incidence of respiratory tract infections. If vitamin A increases the risk of respiratory infections, its high content in modern cod liver oils will only mask the full benefit of adequate vitamin D nutrition.”

    “As the prevalence of vitamin A deficiency in the United States is apparently much lower than the prevalence of subclinical vitamin A toxicity, we cannot recommend cod liver oil for either adults or children. (We exclude fish body oil from our warning, as it contains no vitamin A or vitamin D but is a very important source of omega-3 fatty acids.) For example, in a recent assessment of serum retinyl esters in a group of obese individuals, four percent had levels >10% of total retinol which usually indicates hypervitaminosis A. Instead, a diet rich in carrots, sweet potatoes, cantaloupe, and other orange fruits and vegetables will supply all the carotenoids the body needs to make retinol without the potential for hypervitaminosis A, especially when additional preformed retinol already exists in dairy products, eggs, and fortified cereal. We wish our diet were as rich in vitamin D. With the exception of infants on formula or toddlers drinking large amounts of milk or fortified juice, adequate amounts of vitamin D are virtually impossible to obtain from diet.” [7,8,9]

  • http://rossbergfalk.com Ross Bergfalk

    Excellent work. This is just what I need to show my patients the importance of Vitamin D supplement here in the great state of Minnesota, USA. Love your work.

  • Drew

    So which is it; cannot make enough vitamin D in winter (second diagram), or 30 minute exposure to make enough vitamin D in winter (fourth diagram)?

    • david

      Cannot make enough Vitamin D in winter above latitude 42N

    • Garret

      Cannot expose skin to sunlight for 30 minutes above latitude 42N in winter without serious risk of frostbite and/or hypothermia.

      • david

        The face is sufficient apparently.

  • Jesse

    I find it interesting that despite your great infographic and obvious research into this topic, you completely miss the point. You should be getting your Vitamin D from SUN and not from a PILL. You stress the importance of getting sufficient amounts of Vitamin D from the sun, and then turn around and completely undermind it by popping a pill! Then you list Margarine on list of “best” sources for Vitamin D.Margarine is the original Snake Oil of foods!

  • the Viking Diva

    On most winter days at 40 deg N I am not willing to expose that much of my body to the elements. But I can expose my face. Does 30 minutes of sun to *any* amount of skin do the job, or does that only work if I can expose *all* the surface shown in the figure?

  • Charly

    So, according to this map people in Punta Arenas, Ushuaia or Grytviken are getting enough sunlight????

  • Kristóf Jakab

    I would like to translate it to hungarian, how can I do? May I have the source image?

  • MikeK

    This article forgot to mention best time to get sunlight exposure is between 10 am to 2 pm. Noon is the best time since UV is higher. Also UV rating can change by the day. I don’t think 10 minutes is enough. I think 15 to 20 minutes would be more accurate.

    I take vitamin D3 daily.
    http://www.iherb.com/Now-Foods-Vitamin-D-3-Highest-Potency-5-000-IU-120-Softgels/10421?at=0

    It is difficult to get it from diet. Also cloudy days and pollution can block the UV rays. Steve Gibson on Security Now mentioned he couldn’t get enough vitamin D3 from sunlight which meant he had to use supplementation. He said he is currently taking 10 000 IU which is impossible by diet alone. I don’t recommend taking this much unless you get a vitamin D blood test. 5 000IU should be safe for most people.

    Here is a site where Steve Gibson shares his knowledge on Vitamin D.

    http://www.grc.com/health/vitamin-d.htm

  • Tom Gibson, D.C.

    I have been doing a little research myself on the benefits of vitamin D specifically on the impact it has on the immune system and the correlation to less sun exposure in the winter and higher incidence of colds and the flu. Thank you for the sources also!

  • Cwolf88

    Several caveats:

    1. Over 50 y/o skin produces 75% less D3. Dunno if this is a step or ramp effect.

    2. Obese excess bodyfat sequesters D so they need higher doses.

    3. Both latitude and city dwelling decrease D exposure. UVB varies as BOTH northern-southern latitude.

    4. Diet is a minor source, but even so, today’s youth drink dramatically less milk (CDC).

    5. Studies in high sun areas, or even high sun athletes (e.g. surfers in Hawaii), still show D3 deficiency. A hypothesis is that water exposure washes D3 containing oils off the skin.

    6. D3 utilization depends on co-factors (http://www.vitamindcouncil.org/newsletter/more-vitamin-d-questions-and-answers.shtml):
    • magnesium
    • zinc
    • vitamin K2
    • boron
    • a tiny amount of vitamin A

    7. Raising deficient D3 serum levels (25(OH)D3 test) to 50-80/100 ng/ml) may require early high doses (50,000 iu/day for 8 days). Maintaining that serum level may require some trial and error dosing/testing. 50k iu sounds like a lot, but some studies have given 500,000 iu in one dose.

    8. You can buy the tests online. http://www.directlabs.com (you get a voucher & go to a local draw site) or order the home kit (you put a drop of blood on the card and mail in)(http://bit.ly/h95JIO ).

    9. You can find your Solar Noon at http://www.esrl.noaa.gov/gmd/grad/solcalc/

  • http://billmcgonigle.com Bill McGonigle

    The other trick is going to be climate – depending on factors such as the Gulf Stream, some areas are going to have warmer temperatures and therefore people will wear less clothing and be outside more often. Cold and north creates a double-whammy situation.

    A few things about Vitamin D levels to be aware about: it can take six months to achieve a stable blood level of high Vitamin D by supplementation, individuals vary in their responses – it’s hard to generalize a dosage, and there’s a blood test for Vitamin D levels – those really interested in optimizing can work with their doctor on this. There’s guidance and recommendations in the book TRANSCEND – D3 being one small component of their life-extension program.

  • http://www.barefootandhealthy.com Free Vitamin D

    This is an excellent chart, I am very impressed with the way it is laid out and explained clearly.

    One interesting thing to note is the form of vitamin D you’re getting when taking supplements. Vitamin D “as cholcalciferol” is the type your skin produces when exposed to natural sunlight, and should be sought out when looking for a high-quality vitamin D supplement.

  • mau

    So from looking at that map, I now understand why I am white! Ancestrally anyway, all the peoples from 0-42 degrees have at least some color, maybe less so in east Asia, but still, rather trippy. Even just looking at where that line falls in Europe, thats right where people start to have some color!

  • http://condalmo.wordpress.com Matt

    You aren’t supposed to eat the margarine; you’re supposed to smear it all over your skin, to enhance the power of sunlight.

  • mewrishi
  • http://jcroucher.com John

    No problem getting sun in Australia. I step outside for 10 mins in summer with no sunscreen on and I will be burned.

    • K-eM

      Same is true in Colorado.

  • D3 Helped Me!

    Great inforgraphic.

    I’d add:

    The dianostic test is the “25 HYDROXY D3 TEST” (not the 1.25, that will give you fake postive results)

    Actually, its north of 37 degrees latitude, not 42.

    Also, its D3 that is most critical! But its fat soluable so don’t take more than 2000 iu/day without doctor’s supervision

    Also, if people tried to eat that much salmon or drink that much milk every day instead of supplementation, they would get very ill, so you might want to suggest that they don’t and instead supplement:

    http://www.huffingtonpost.com/dr-frank-lipman/vitamin-d-what-you-need-t_b_308973.html

  • Kevin Henry

    Readers might be interested in today’s New York Times article on the subject: http://www.nytimes.com/2010/11/30/health/30vitamin.html.

    It seems to me that your enthusiasm for Vitamin D supplements has led you to present as facts what are tentative and controversial findings. For example, your graphic says that “Latest Research” calls for 2,000 IU per day, but according to your accompanying data this was taken from a press release, without any study to back it up.

    Of course, you are very good at creating these infographics, but that only increases your responsibility to present things accurately.

    • david

      study here: http://archinte.ama-assn.org/cgi/content/full/169/6/626

      “Current recommendations for dosage of vitamin D supplements are inadequate to address this growing epidemic of vitamin D insufficiency. Increased intake of vitamin D (>1000 IU/d)—particularly during the winter months and at higher latitudes—and judicious sun exposure would improve vitamin D status and likely improve the overall health of the US population. Large randomized controlled trials of these higher doses of vitamin D supplementation are needed to evaluate their effect on general health and mortality.”

      • Kevin Henry

        Right, so why do you say 2,000 when the study you’re citing says “>1000″?

        According to your references the number 2,000 seems to come from a UC Riverside press release. There’s nothing wrong with that per se, but it’s misleading to say that the “Latest Research” indicates 2,000 IU/day.

  • Elise

    Timely article on NPR about appropriate doses of Vitamin D (according to the Institute of Medicine in the US):

    http://www.npr.org/2010/11/29/131668100/medical-panel-don-t-go-overboard-on-vitamin-d

  • Carolyn

    Wow – and now the Institue of Medicine reports we get enough vitamin D! http://www.nytimes.com/2010/11/30/health/30vitamin.html?_r=1

  • vjt
  • kanza

    Thank you for the information about Vitamin D. Check the facts about MS and Vitamin D, too. Good information.

  • http://cbt20.org Howard O

    We are covering the Vitamin D issue on the Canadian BioTechnologist 2.0 Blog http://bit.ly/gCSglo Do you really need to beef up on vitamin D? C

  • Barry Lomax

    Regarding Vitamin D
    I am a Naturopathic Doctor/Nutritionist who started reading about nutrition when I was 11 years old. Vitamin D is the lastes fashionable vitamin. I could give you each fashionable vitamin for the last 30 years.
    Anyway, vitamin D does have health benefits, however it has to be used in a natural manner or over long term use of isolated synthetic vitamin D, there will be consequences.
    All the propaganda about vitamin A being toxic is complete nonsense. It is based on 2 things. One is the misinformation from explorers who supposedly dies from eating polar bear liver, they actually died from cadmium poisoning. The other source is from all the side effects and birth defects caused by accutane or synthetic vitamin A (enantiomer that has opposite effects to natural vitamin A)
    Vitamin D requires vitamin A and omega 3 fatty acids for the body to transport and utyilize calcium in the tissues. Otherwise the calcium will accumulate in organs, blood vessels etc. The ratio found in nature is about 10 to 1 vitamin A to D. In nature, there is a synergy between nutrients that allows the vitamin D dose to be effective at lower doses as long as the A and omega 3s are there. Nature knows what it is doing, cod liver oil has the perfect ratios of D, A and omega 3 fatty acids.

  • http://thegreatestworm.com Conodont

    Very pleasing layout. The different yellows hold things together and aren’t harsh or distracting. Note two typos: “conficting” and “practioners”.

  • carlos

    What the heck is “yomming”?

  • BenR

    http://www.chicagotribune.com/health/la-he-vitamin-d-20101206,0,7905462.story

    The Institute of Medicine just released a study saying that Vitamin D is basically completely overrated.

  • datacorrupt

    No mention in the cited NY Times article, or here, of the hypothesized link between vitamin D deficiency and developing Multiple Sclerosis. Also interesting to note the fact, yes fact, that the incidence of MS increases the further away from the equator you live. ie, higher incidences per capita in Tasmania (way way south) and Scotland (way way north).

  • Aliza

    Two thoughts– there’s been some research of late on Vitamin D deficiency in Canada (comes out of Statistics Canada’s CHMS study), and there’s a little evidence that Vitamin D may play a role in tuberculosis switching from latent to active.

  • ArnoN

    A very extensive overview of vitamine D and its importance for health has been written by A. Zittermann (University of Bonn, Germany) and published in the British Journal of Nutrition in 2003. The paper is available for download (pdf file) at:
    http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=909956

  • Dan Watson

    One of the important constituents required by our body is Vitamin D. Lack of this vitamin weakens the absorption level of calcium and results in weak bones and fractures.
    I suffer from calcium deficiency and have been taking Vitamin D supplementary drugs after studying them on Findrxonline. This site is just what is required. You have all the information you need and can even procure the drugs at reasonably moderate prices. These drugs have been of immense help and I now recommend them to my family and friends too.

  • http://whyvitamind.blogspot.com Saibal Mitra

    One has to consider that vitamin D only switches on certain genes that produce various enzymes involved in regulating may processes in the body. The question is then why animals have evolved to modulate these processes using vitamin D. As I explain here, a possible explanation is that vitamin D levels falling is an indicator of Winter approaching and it then makes sense to let processes that use a lot of energy, like the immune system, function in a more energy efficient way.

  • Paul Bailey

    I would Just like to say I’m 47 live in the UK and never felt better since I started taking 4,000 IU of D3 a day from Nov 2010.

    I felt very downbeat every winter for no reason. 7 years ago and last year I had de-pigmentation on patches of skin I had Vitiligo a autoimmune disease. When I looked back both of these times was when I was working in offices in basements during winter or very little light coming from the window.

    Give it a try :)

  • http://www.twitter.com/aprilsun April Sun

    This may prove to be noteworthy: http://bit.ly/exQB39

    Joint Effects of Dietary Vitamin D and Sun Exposure on Breast Cancer Risk: Results from the French E3N Cohort

    A 10 year study followed over 67,000 women in the French E3N cohort and the results of which were published in January 2011. They found a significantly lower risk of breast cancer for post-menopausal women living in regions with the highest UVRd.

  • Aria

    I don’t understand why some comments seem so antagonistic. It seems perfectly clear to me (maybe because I haven’t seen the sun in months:)) that if one can’t get the recommended amount of daily sunlight, it might be beneficial to take a vitamin D supplement. The sun is absolutely the most efficient tool for our bodies to synthesize vitamin D; however, all needs are not identical and there is not one specific set amount that is the “right” amount. Skin pigment is a good indicator and people with lighter skin require less sun exposure to synthesize their required amounts.I recently found out that I am deficient through blood work and I was prescribed 50,000 IU twice a week for 8 weeks. I still haven’t picked it up from the pharmacy. I told my doctor that I was already taking a D3 supplement daily and she said it wasn’t enough; however, knowing that it is possible to get too much D in pill form makes me leary of dosing so heavily. The method of synthesis differs when ingested and I’m not even sure if its effective in an unnatural form. Still doing the research.For the record, it is not possible to overdose on vitamin D from direct sunlight because as easily as it is produced, it is also degraded when not necessary. I wonder if a tanning bed would help? I heard they have mostly UVA rays but I think some of the high-end equipment offers UVB bulbs…or is it the other way around?

    • http://wikipedia Brandon Wolfe

      nerd

      • http://www.vitimindaintwhatitscrackeduptobe.com Jack

        Thats so bad if i saw u id swear at you in latin

    • http://www.twitter.com/aprilsun April Sun

      FYI, this comment was meant to be in response to your post. http://www.informationisbeautiful.net/2010/vitamin-d/#comment-40832

      It would have been more effective had I actually hit the reply button.

    • jainener

      If you want great information on Vitamin D, go to this website.
      http://www.mercola.com
      Getting my levels of Vitamin D in the optimal range has changed my life. I take 10,000 ius every day (at the recommendation of my doctor) and it is VERY hard to overdose on vitamin D even in pill form. It can take months to get your levels to optimal even with high weekly doses. It took me over a year. Optimizing our vitamin d level is one of the easiest and least costly ways to improve your overall health.

    • Rita

      Been there~ I was prescribed 50,000 units Vit. D to take one time per week for up to 3 mos. so to save money I went to our local pharmacist and got a 3 mo. supply of 5,000unit 100/1 per day…now after 3 months I ended up in E.R. with severe chest, jaw pain, and muscle pains. It has been 4 days since I discontinued taking this and my chest pains and muscle pains are for the most part gone…Now I just make sure I get sunlight, and eat herring for my main meat, and try to get the daily recommended amt. of milk…check out the chart for Vit. D…http://www.healthalternatives2000.com/meat-protein-nutrition-chart.html#turkey bacon
      hope this helps you…I wouldn’t recommend supplements of any kind~anything supplement is artificial (loaded with synthetics and chemicals) I looked up the dangers of every ingredient in vit d and the find was scary. And even scarrier, I found the same ingredients in the potassium I have been taking for 7 yrs…it is now gone too…I have come to love bananas, avocados, and V-8…