CholesterolMicronutrientsPublic Health

Vitamin D Deficiency

US Guidelines

In 2010, at the time of writing my obesity book, the US did not have a “Dietary Reference Intake” for vitamin D. Instead, the US had an “Adequate Intake” suggestion – they thought that 400IU (10mcg) would be adequate.

This was revised in 2011 when the US decided that the Recommended Dietary Allowance (RDA) for everyone from the age of 1 to 69 should be 600IU (15mcg) and 800IU (20mcg) for those aged 70 and over. (This post doesn’t discuss the different forms and sources of vitamin D, but this is an added complication.)

UK Guidelines

The Dietary Reference Values 1991 book is still the UK ‘bible’ for recommended nutrient intakes. This has no vitamin D targets for anyone aged 4 to 64, unless pregnant or breastfeeding – then it’s 10mcg per day. Over 65’s are also advised to have 10mcg daily.

The official European position still seems to be that of the early 1990s. This leads to this 1993 document (page 143), which confirms the lack of targets for those aged 4 to 64, as set out in the UK Dietary reference values book (1991).

On the same “European Food Information Council” site, a “mini guide” from June 2006 suggests that “European Union Recommended Daily Amounts for Nutritional Labelling of Food Products” for vitamin D should be 5 µg (that’s 5mcg).

I have no idea why the US originally only saw fit to suggest an adequate intake until 2011, or why the RDA is now 15mcg. I have no idea why the UK still doesn’t consider vitamin D to be a vital nutrient with a daily requirement. I have no idea why the recommendations for vitamin D differ from 0mcg to 15mcg for UK to US populations. This is clearly not robust, or scientific.

What I do know is:

1) Vitamin D is utterly vital for human health

Vitamin D is critical for the absorption of calcium and phosphorus. Deficiency in vitamin D can lead to tooth decay, muscular weakness and a softening of the bones (rickets), which can cause bone fractures or poor healing of fractures. Enter “vitamin D” into pubmed and over 65,000 academic articles will be listed. Vitamin D is increasingly being studied as a critical factor in the most serious human health conditions, not least heart disease, cancer and diabetes.

Vitamin D is found naturally in oily fish (for example herring, halibut, catfish, salmon, mackerel and sardines), eggs and dairy products and unnaturally in fortified breakfast cereals. (You never need junk cereals to get vitamin D – take a supplement if you don’t want to consume vitamin D naturally for some reason).

2) The average person is not getting enough vitamin D

a) US data is quite old. This November 2014 factsheet references a journal article from April 2010, which reviews data from 2005-2006.

Average male intake from diet alone for adult males in the US ranged from 5.1mcg for 19-30 year old males to 5.6mcg for males ≥ 70 years old. Average female intake from diet alone for adult females in the US ranged from 3.6mcg for 19-30 year old females to 4.5mcg for females ≥ 70 years old.

The article reported that 37% of the US population take vitamin D supplements, and this increased the intake to 6.9mcg for 19-30 year old males and 8.8mcg for males ≥ 70 years old and to 5.0mcg for 19-30 year old females and 10mcg for females ≥ 70 years old.

The lowest intake, diet alone for 19-30 year old females was less than a quarter of the US RDA; even the highest intake – women over 70 years old taking supplements – was two thirds of the intake recommended.

b) The UK data is provided annually by the UK Family Food Survey. The most recent report at the time of writing this blog is the 2013 Family Food Survey. This reported that the UK average intake of vitamin D from all food and drink was approximately 3mcg for each of the five years from 2009-2013 (Table 3.7 UK average energy and nutrient intakes from all food and drink 2009-2013). This is one fifth of the US recommended daily intake.

What the data tells us

Public health officials in the US and UK should be issuing emergency notices that vitamin D deficiency is a serious health risk to citizens. Populations should be advised to consume more foods naturally rich in vitamin D – oily fish, eggs and dairy products. Oh, but those just happen to be the fat rich foods that fat phobic public health advisors tell people to avoid! Even when oily fish is recommended, it is rarely more than twice a week. Yet we need approximately 220g of sardines (with bones) every day to meet the RDA of 15mcg of vitamin D. Vegetarians would need to eat 39 medium eggs each day (2,455 calories) to get 15mcg of vitamin D.

The other urgent piece of health advice needed is – sunbathe! We need to be exposed to the sun – without sunBLOCK – for a safe number of minutes (depends on skin type, location, time of the year etc) as regularly as possible to build up our vitamin D reserves. Being a fat soluble vitamin (along with A, E and K), vitamin D can be stored by the body. A good build up during summer months will help for annual health, but we should be rolling up our sleeves and trousers to expose limbs even on sunny winter days and/or consuming sufficient dietary vitamin D during the winter period.

What do our dear governments do instead? Scare us away from sun exposure, tell us to cover up and/or use sunBLOCK every time the sun shines and advise us to keep avoiding fat in food.

Just to complete the trilogy of bad advice – vitamin D is made when sunlight synthesises cholesterol in skin membranes. Avoiding vitamin D rich foods AND blocking sunlight from the skin AND cholesterol lowering medications and dietary supplements (e.g. plant sterols) ALL conspire together to lower vitamin D.

Dr. Robert Scragg, Associate Professor in Epidemiology at the University of Auckland, New Zealand, proposed back in December 1981 that vitamin D deficiency plays a key role in cardiovascular disease. If he was right, our diet/sun/cholesterol advice is not only wrong – it’s doing the exact opposite of what it hoped to do – raising, not lowering, heart disease.

25 thoughts on “Vitamin D Deficiency

  • Great article which perfectly demonstrates some of the major problems with our health authorities and government. Vitamin D deficiency is the result of people following the advise which is all based in fear and bad science.

    I read a book (Cannot remember the name) that went into details about vitamin K2 which is needed to work with the vitamin D. K2 sources are grass fed animals which again are few and far between these days with all the modern farming. I think it shows just how eating real food as it is meant to be and getting a spread of nutrients is vital.

    I often hear that we cannot get enough vitamin D especially in places like the UK. What is your opinion? I don’t understand how we cannot when we must have done throughout history.

    Thanks for an excellent article.

    • I’ve read research on what limits people’s vitamin D from sunlight – one common environmental culprit is pollution. Sunlight can’t penetrate smog.

      Added in lifestyle factors such as adults not having lunch breaks and kids growing up in flats without gardens and not being allowed to play out on their own, then lots of people have limited exposure to the sun.

  • First of all I love this site , so informative.
    I have just had my regular blood test and my results came back with Glucose 5.7 , Cholesterol 7.5 ( never changed for 5 years) and said my Vitamin was low.
    Solution was to come in a talk to my GP about medication ???
    Ok I was put on a Statin 12 months ago but came off it because I was aching constantly so I told my GP . 4 Months ago I was put a 1000 units of Vit D supplement . When I went for the bloods done this week I was told to not take the Vit D , so result was low Vit D and was recommended to take a supplement. I am so confused . Should’nt my GP know what I take ? and why not test bloods with Vit D supplement?
    Come to think of it the time I was on Statins I never had a test to see if it had come down!

    • Hi Tim
      Many thanks for your lovely comment on the site. The rest of your post reminds me why I stay well away from doctors unless absolutely necessary! Once in ‘the system’ people find things are being ‘done to them’. Test for this, give tablet for that – no wonder the medical profession is the third leading cause of death!

      As the post alludes to above – it sounds like sunshine would fix this jigsaw puzzle. Sunshine provides vitamin D (one problem sorted) but it does this by synthesising cholesterol/turning it into vitamin D. Cholesterol goes down naturally (because it has been used for a vital function) and vit D goes up. Trouble is – docs warn us away from the sun!

      GPs should know what to take. However, I’ve not met many (any?) who’ve had more than half a day’s nutritional training during their many years of training. “Let food be thy medicine” obviously got dropped from the curriculum somewhere along the line!

      Good luck working it out – at least you’ve realised you’ll need to!
      Best wishes – Zoe

  • Zoe, estimates of how much vitamin d we need to take as a supplement vary considerably. What’s your view? I’ve seen it said that we need 100 mcg of vitamin K2 for every 1,000 IU of vitamin d.

    • Hi Stephen
      So sorry – again! for the tardy reply – old comments are just appearing weeks later for some reason! Being looked into.
      I’ve not looked into vitamin D in this way – the guy commenting on this post (Ted/Edward Hutchinson) is really good on vit D.

      Search “Oliver Gillie vitamin D” – he’s another person right into this topic

      Dr David Grimes – vit D and cholesterol – big book but very readable.

      Hope one of these has the answer!
      Best wishes – Zoe

  • I had to laugh at the mention of Cod Liver Oil. My wife thinks I’m really weird because I actually love the stuff and drink it straight from the bottle!

    But then I love Marmite as well.


  • These sorts of enigmas abound in ‘modern’ medicine. It has been known for years that Vitamin D deficiency is a risk factor, or at least a marker, for cardiovascular disease (CVD*). Adding homocysteine, hs-CRP and B12 and folate to the investigations show how important these are as risk markers for CVD.

    Yet, in Australia, the government recently stopped paying for these investigations, making them available only as private pay, in a routine screen. One now has to have evidence of an abnormality in these markers in order to have government reimbursement. How one does that is not clear to me – wait for rickets, for example? The stupidity of such a policy in the face of the government’s own admission that these markers are frequently abnormal in the Australian population, is simply incomprehensible.

    As always, well done Zoë.


  • Hi Zoë,
    The best advice when it comes to governmental advice regarding lifestyle, diet and supplementation of vitamins and minerals is to ignore it. There may be the odd bit of advice that is correct (yet to find it) but overall it and that of linked organizations is misguided at best. We are advised not to eat many of the beneficial foods such as natural fats plus many types of meat and replace them with an unhealthy array of carbohydrate biased “foods” that do little other than supply empty calories and manufactured fats that our bodies are not adapted to deal with. The net result is people that are malnourished, ill and very often obese as well. The fact that decades of healthy advice have done nothing to improve health but made things worse is completely overlooked. One would think that at some stage the people promoting such rubbish might start considering that they are wrong (corruption and commercial interest aside).

    Vitamin D is, as you say, utterly vital for our health and an inadequate intake will result in many health problems. The RDA is far too low and even if people take a supplement supplying the recommended amount they are still likely to have a low serum level. Stupid advice against sun exposure does nothing to help and, unfortunately, at the UK’s latitude the months September through April provide little or no UVB even in the south. As a direct result of misguided dietary and sun exposure advice we are experiencing many health problems that would otherwise not exist.
    However, vitamin D supplementation alone will not be sufficient if we there is an inadequate supply of cofactors such as magnesium (many are deficient), vitamin K2, vitamin A, boron and zinc. Of these it is vitally important that there is an adequate supply of vitamin K2 but, like magnesium, many people do not obtain sufficient from diet (especially if they follow the cholesterol/diet hypothesis advice and avoid the very foods that they should be eating). Without adequate vitamin K2 calcium will not be directed to bones and teeth and will deposit in the cardiovascular system, tissue and organs. Calcium supplementation which is often promoted to prevent osteoporosis will not prevent osteoporosis when vitamin D levels are too low and the vital cofactors are also at inadequate levels. Dr. Weston Price noted how important K2 was (referred to at the time as Activator X) as a factor in the excellent health of people not consuming the western diet. Sadly the results of his research and the implications for health do not align with the agenda of the food and drug industries so they are ignored.

    • Hi Barry
      So sorry for the delay in approving this – a month’s worth of comments have just appeared – I wondered why it had gone quiet!

      Your knowledge (and regard for Weston Price) is a credit to you!
      Best wishes – Zoe

  • Great Article Zoe, an area much overlooked.
    Here in Aus, the Sun recommendation is for 15 minute exposure to 85% of our body, however the Cancer council fear we will die if we naturally support our Vit D levels.

    It is worth mentioning the role of K vitamins, particularly K2, also from organ meats, and the like.

    Best regards

  • Thanks Zoe, another great article showing the total lack of rational thought. I really despair at this lunacy.

    Another example of the mindless recomendations is that shown on vitamin supplements. have you ever noticed the caveat regarding dosages?

    For example: on 50mg vitamin C bottles it will say “Dosage 1 tablet per day – WARNING DO NOT EXCEED THE STATED DOSE”

    Strangely, on 1500mg vitamin C bottles it will also say “Dosage 1 tablet per day – Warning DO NOT EXCEED THE STATED DOSE” The fact that the 1500mg dose is 30 times larger seems to have escaped their attention!

    To me it shows how these things are largely plucked out of thin air and turned into goverment recomendations. A bit like the daily alchohol intake which has now been revealed to be based on nothing at all!

    Great stuff, keep it up.

    Have a great Christmas.


    • Hi Ray
      So sorry for the delay in approving this – a month’s worth of comments have just appeared – I wondered why it had gone quiet!

      I remember writing an article about vitamin D years ago, before I challenged everything, and added the “excess dose” comment and someone mentioned life guards in LA who likely get tens of thousands of IU per day. I thought “good point”! If we do get too much sun, the body tells us – we get nauseau and lie down in the shade quietly – smart mechanism!

      Best wishes – Zoe

  • Zoe, I’m glad to see you writing on this.

    Michael F. Holick, Ph.D., MD was one of the first researchers to emphasize the importance of Vitamin D. His book, “The UV Advantage” has charts (“Safe and Effective Sun Exposure for Vitamin D Production”) in the back of the book that show how much sun exposure is needed. It varies widely based on time of year, time of day (angle of the sun determines how much UV you get), latitude of exposure (tropics are low latitudes) and skin type (fair versus dark). In the tropics (Honolulu) in July, a fair person (Holick’s “Type 1”) could get enough Vitamin D in 1 to 5 minutes at mid-day (11 am to 3 pm); a very dark person (Holick’s type 5-6) would need 15 to 20 minutes. In December those times would be 10 to 15 minutes (for fair skin) and 45 to 60 minutes. Quite a wide range! At other times of day than mid-day, more time is needed.

    Even longer exposure is needed as you go north. In Alaska, those times are 5-10 minutes (fair, mid-day, July), 30-40 minutes (dark, mid-day, July). In December, you can’t get enough Vitamin D from the sun in Alaska.

    From November through February in latitudes above 35 degrees (includes New York, San Francisco), you simply can not get enough vitamin D from the sun. Above 50 degrees (includes Anchorage, Stockholm), you can’t get enough Vitamin D from October to March.

    One site I’ve found to be useful is:

    They have information pertaining to many diseases with lots of references and they keep up-to-date with new research. Unfortunately, you have to pay to see many of the articles. Still, there’s a lot available for free.

    The only way to know your Vitamin D levels is a blood test for your 25(OH)D levels. The Vitamin D site and many researchers based on research recommend higher levels than most physicians.

    I’ve been following Vitamin D research for 10 or 12 years. I’ve been interested to see that my endocrinologist and family doctor have recently begun testing Vitamin D levels, so the importance is at least starting to filter down to physicians. It doesn’t seem that they should always be the last to know.

    • Hi Michael
      So sorry for the delay in approving this – a month’s worth of comments have just appeared – I wondered why it had gone quiet!

      Great to see someone researching vit D at this level. Oliver Gillie is another person massively interested in vit D and Dr David Grimes (Vit D and Cholesterol is his book) is also fascinating.

      Best wishes – Zoe

  • Dear Zoe Harcombe- I have just finished reading your e-book and a more elegantly written, well argued work I cannot imagine. Thank you. Though I’m not remotely overweight myself (though T2DM for nearly sixty years – Mody, I believe, together with my brother) I find myself fascinated by biochemistry- and a need to argue my corner with the diabetic nurse regarding statins.
    Your piece on Vit D reminds me that it’s time to get down to Horrid and Badl to stock up on D3 oil for the winter. So a double thank you.

    • Hi Jan
      So sorry for the delay in approving this – a month’s worth of comments have just appeared – I wondered why it had gone quiet! – and many thanks for your kind words :-)
      Best wishes – Zoe

  • Great article. I would love to recharge the vitamin D levels in winter by “rolling up my sleeves and trousers” but it is my understanding that here in northern Europe the sun is only strong enough for that from May to September.

    • Hi Colin
      So sorry for the delay in approving this – a month’s worth of comments have just appeared – I wondered why it had gone quiet!

      I read somewhere that Birmingham is the latitude North of which winter sun doesn’t help. I’m south of Birmingham, so I can get some benefit, but it does help to understand why people of Asian origin in Glasgow suffer disproportionately high heart disease. Vit D is crucial in all health – including heart health – and you can’t get vit D from the sun for half the year and those more used to the sun need more to have an impact. Double whammy!

      Best wishes – Zoe

  • First of all, it’s great that you raise awareness about vitamin D. Its immune system supporting role and overall importance in health (and disease) should be emphasized whenever possible.
    On the other hand, sufficiency is still extremely conservatively set in North America and it was just recently pointed out by scientists that the IOM recommendation of 600 IU/d was based on flawed math and in fact their own data suggest around 8,800 (!) IU/d intake for 97 % of the population to reach 25(OH)D serum level considered sufficient in NA (30 ng/dl = 75 nmol/l). Not to mention the fact that most vitamin D experts recommend a range of 40-80 ng/ml. This is in line with both the measurements in indigenous people having plenty of sun exposure (around 60 ng/dl) and with the best estimations of 15-20,000 IU synthesized in the skin daily.
    Also, sun exposure should be priorotized over food and supplements, because we are still not sure what role the other 20+ compounds play which are synthesized in the skin along with D3. I strongly believe that the natural solution is always superior to supplementation. However, there is no point in suggesting to people in the UK that they expose skin to sunshine during (late) autumn and winter months. According to experts, the rule of thumb when it comes to sufficient UVB level in sunlight is that length of your shadow must not exceed your height. When it does it’s hopeless to produce vitamin D. So whenever the sun is high enough, taking a sunbath that does not cause burn is ideal. The next best thing is to obtain a quartz lamp specifically developed to provide high UVB emission and reduced UVA. If it’s too expensive or too inconvenient take D3 supplements in the range of 70-90 IU/kg body weight daily.

    • Hi erdoke
      So sorry for the delay in approving this – a month’s worth of comments have just appeared – I wondered why it had gone quiet!

      Many thanks for sharing that even the latest revision may be a significant underestimate. Verner Wheelock has been saying the same, but I can’t find his recent post on this (

      Best wishes – Zoe

  • I’m 65 and was born in England. When I was a little kid, we got cod liver oil capsules (from the National Health) to take every day during the winter. During school we had outside recess as well as sports all year round (weather permitting) and during summer vacation we were generally kicked out of the house at breakfast time with sandwiches and not expected to be back before tea time. No sunblock.

    I’ve continued to supplement with vitamin D3 all my life, except when I lived in the Middle East. These days I take 5,000 IU daily. I never use sunblock, not even when I lived in the Middle East, much to the horror of my friends.

    I’ve been part of the Grassroots Health vitamin D study ( ) for several years now and my vitamin D level runs around 60 – 65ng/ml.

    • Hi Hugh (great full name!)
      So sorry for the delay in approving this – a month’s worth of comments have just appeared – I wondered why it had gone quiet!

      Many thanks for the link and the reminder of our younger days – this was certainly how my parents were brought up and I remember them bringing me up in the same way – no sunblock, out all day, cod liver oil (I seem to remember syrup, not tablets!) I still don’t use sun block – also much to the horror of friends!

      We’ll see who’s right!
      Best wishes – Zoe

      • My friends are appalled by my refusal to use sunblock. Especially as I’m a fair-skinned redhead. But I’ve never had a problem, even in the Middle East. So I just tell them I’m allergic to some of the carriers and perfumes in sunblock. It’s not true, but it shuts them up. :)

        IIRC, the National Health used to give us orange juice concentrate and rose hip syrup for vitamin C as well as cod liver oil.

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