My vitamin D results are in (take 2)

One of my projects for 2009 has been to optimise my vitamin D levels. My first ever check was in April, which revealed a frankly low vitamin D level of 15 ng/ml (37 mmol/l). I subsequently set about correcting this by taking 3000 IU of vitamin D (in gel caps) a day. In July my level had risen to 31 ng/ml (better, but not ideal). Since then, I have been taking 5000 IU of vitamin D a day. A recent test reveals that my vitamin D level as 44 ng/ml. This is three times as much as I had back in April, and now puts me in what some would regard as the ideal range (40-60 ng/ml). My plan is to stay on my current dose and re-check levels in a few months time.

I was reminded of the importance of optimising vitamin D levels in a piece published this week in the Journal of the American Medical Association [1]. The piece highlights a voluminous and growing body of evidence linking vitamin D deficiency or insufficiency with an increased risk of a wide range of conditions including osteoporosis and bone fracture, muscle weakness, cancer, autoimmune disease, diabetes, schizophrenia, depression, lung dysfunction, kidney disease, and cardiovascular disease.

The piece also highlights the fact that low levels of vitamin D can be common. For example, in one study of Americans aged 1-21, the prevalence of vitamin D deficiency or insufficiency (vitamin D < 15 ng/ml and 15-29 ng/ml respectively) was found to be 70 per cent. Moreover, the point is made that recommend intake levels are due for revision ” in an upward direction.

Such recommended amounts need to embrace two fundamental things: what dosages are likely to keep the majority of people out of deficiency/insufficiency, and what levels are safe. What seems clear is that while optimal dosages vary between people, many individuals (such as I) require several thousand IUs each day to maintain good levels of vitamin D in their bodies. You can read more about this here.

And what of safety? The current upper limits quoted in the article are 1000 IU for infants (children aged up to one year) and then 2000 IU thereafter. The article quotes Professor Michael Holick, professor of medicine, physiology and biophysics at Boston University School of Medicine in the US, and a long-time advocate of vitamin D. Holick thinks the risks of reaching toxic levels of consumption are overstated. According to the JAMA piece He [Holick] would raise the upper limit to 5000 IU per day for children and suggested that an adult could receive up to 10 000 IU of vitamin D per day without any adverse effects.

The article ends with Holick’s response to the question of whether doctors are getting the message regarding the potential importance of vitamin D. Holick claims “What happens is the patient hears about this in the news and brings it to her physician’s attention. The physician is then reluctant to do the test, but when he does, he finds the patient is vitamin D deficient”and then he gets religion.”

This strikes me as an important example of how individuals can contribute to the education of their doctors. I was only telling a journalist yesterday how important it is, I think, for doctors to be prepared to be taught a thing or two by their patients.


1. Mitka M. More evidence on low vitamin D levels fuels push t revise recommended intake. JAMA 2009;302(23):2527-2528

26 Responses to My vitamin D results are in (take 2)

  1. Nigeepoo 17 December 2009 at 10:40 pm #

    Have you noticed any difference to how you feel, or how often you get a cold/flu?

    How much oily fish/day do you eat on average? I’m finding that 5,000iu/day D3 + ~100g/day oily fish is very mood-enhancing.

    n=1, though!

  2. Dr John Briffa 17 December 2009 at 11:24 pm #

    No major change in how I feel (think I felt generally very good before, so difficult to judge), but not a single cold or flu since I started supplementing in April. I may not have had one anyway, of course, but there has been a lot of stuff flying around I’ve not even had a sniffle.

  3. Chris 18 December 2009 at 12:02 am #

    Vieth has a great paper on Vitamin D toxicity and safety, “Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety.”

    Puts things in perspective, that those recommending low levels of D or no supplementation are essentially clueless.

  4. Nigeepoo 18 December 2009 at 1:52 am #

    Dr John Briffa said:
    No major change in how I feel (think I felt generally very good before, so difficult to judge), but not a single cold or flu since I started supplementing in April. I may not have had one anyway, of course, but there has been a lot of stuff flying around I’ve not even had a sniffle.

    It’ll be interesting to see how long you can go before you catch something. You’re at a higher risk than me as you see patients, some of whom have a cold/flu. I’ve been on 5,000iu/day since Dec ’07. I had a minor sniffle in Dec ’08 when many people around me were suffering badly. I’ve had nothing since. There are many people suffering badly at the moment, judging from forums that I post on.

  5. dawn hewett 18 December 2009 at 2:44 am #

    I just got my hormone levels tested and found out that I am not producing enough Vitamin D, since I avoid the sun. My physician who is a bioidentical hormone specialist explained to me how important Vitamin D is to maintain a healthy immune system.

  6. Patricia 18 December 2009 at 10:24 am #

    I had my vitamin D levels checked 3 months ago and as they were incredibly low in consultation with my doctor I started taking a vitamin D capsule with 25,000 IU once every three weeks and was already taking a 1000 mg capsule of cod liver oil each day. I seemed to have reacted badly to the supplement as I have never felt so tired in all my life since taking the vitamin D capsule. So much so that I had to go to bed at 8 p.m. each night. The worst period were the three days after taking the 25,000 IU of vit D. Has anyone else experienced any problems with this kind of supplementation? For the moment I have stopped taking any kind of vit D.

  7. Cali Bird 18 December 2009 at 7:37 pm #

    Hello Dr Briffa

    What make of supplements do you take for Vit D?


  8. Dominic Gill 18 December 2009 at 11:27 pm #

    Patricia — Much better to supplement more gradually, as Dr Briff describes. Supplementation MUST be with VitD3 — no other kind. The problem is often finding any VitD3 tabs of more than 400-900IU — I get my 5,000IU tabs from the US, and take 2 of these a day. I would bet that you wouldn’t get any ill effects from such a dose.

    Absolutely IDEAL optimal VitD is more like 60-80 ngl/ml, but 40-60 would be OK. 14 mg/ml is not merely “low”, but VERY low!

    Best source of VitD info on the web is — absolutely worth a visit!

  9. frances 18 December 2009 at 11:30 pm #

    I’ve joined the D’Action grassroots survey too, and have just had my first test results through. They were 25ng…and I cycle everywhere, eat oily fish about 4/5 times a week and am outside everyday for a while. Also, I live in sunny Brighton. I too think that they are mood enhancing or at least mood leveling. I particularly like the fact that you are able to check levels, as I find taking what are often expensive supplements a bit of a leap of faith.


  10. Ted Hutchinson 19 December 2009 at 12:17 am #

    Although 44ng/ml is sufficient to not only maximize uptake of calcium (>32ng/ml) and ensure maximum bone mineral density (>42ng/ml), pregnant and nursing mothers should be aware that in order to maximize the amount of vitamin D3 in human breast milk 6400iu/daily was found to be necessary to raise (>58ng/ml) at latitude 32.
    This is detailed in the Taylor, Wagner and Hollis paper.
    Vitamin D supplementation during lactation to support infant and mother.
    Although 4000iu/daily met the mothers daily needs in full it left babies being born with lower 25(OH)D status than required for optimum calcium absorption

    They also found DAILY use of supplements was required by pregnant and nursing mothers to ensure an even daily Vitamin D3 supply to the foetus & baby.
    It makes virtually no measurable difference for everyone else if you supplement daily or weekly.

    While Dr Briffa will not be lactating he may be interested seeing in the
    Grassrootshealth chart showing disease incidence by 25(OH)D status.
    this may encourage him to go just another 10ng/ml higher and a bit nearer to the natural level at which human breast milk flows replete with D3.

    Although 5000iu cholecalciferol capsules are now available online in the UK may I remind readers these are cheaper from USA discount providers like IHERB providing you don’t order more than £18 in any single order as you then have to pay VAT on import + £8 Post Office handling fee.
    WAB666 Introductory discount code WAB666.

    These recent papers make me think the recent move to encourage mothers to take the “official” prenatal Vitamins available will do little or nothing to reduce MS or other disease incidence.

    Developmental vitamin D deficiency causes abnormal brain development

    Vitamin D, a neuro-immunomodulator: Implications for neurodegenerative and autoimmune diseases

    If we are going to ensure babies come into the world vitamin D replete then we have to ensure vitamin D is getting to the foetus and via breast milk to the baby. As Dr Briffa has discover getting anywhere near 55ng/ml requires a lot more vitamin D3 than is “officially” regarded as sufficient.

  11. Jamie 19 December 2009 at 1:00 am #


    As Dominic said, check your vitamin D supplement to see whether it is D2 or D3. Odds on if the doctor prescribed a high dose like that, it will be D2 & you really should be on D3.

    At 25000IU every three weeks, & with your cod liver oil, you would be lucky if that averages out to 1500IU/day. Starting from such a low level, you are unlikely to bring your levels up anytime soon (the analogy is like trying to fill an Olympic swimming pool with a garden hose).

    You would be far better served taking 10000IU per day for 4-6 weeks, then going on to a maintenance dose of 1000IU per 15kg of body weight thereafter. I would suggest too that you knock the cod liver oil on the head whilst you are trying to get your levels up as this is rich in vitamin A & there is a bit of interference between these two vitamins.

    We are lucky here in New Zealand in that vitamin D3 in 1000IU capsules is very easy & cheap to get hold of. At my practitioner rate is costs me $30NZD for 240 capsules (~10GBP). Very cheap health care that is!

  12. Rarest1 19 December 2009 at 2:22 am #

    If the consumer now has to train the physician perhaps the fastest method would be to inform, and They could be pressured by anxious consumers to “campaign the problem.” They move mountains.

  13. Terry 19 December 2009 at 2:23 am #

    I took 50.000 IU D3 each day for eighteen months, until my level was 150 ng/ml. I’m now on a maintenance dosage of 5.000 IU per day. No problems with these high dosages. Ever. I monitor my calcium intake. No flu, no colds, no sore throats, no swine flu.

    There’s a message there, somewhere.

  14. Anna Salvesen 20 December 2009 at 12:29 am #

    I had been taking 4000iU D3 daily which kept my 25 (OH)D in the 60s or so. Last winter in Dec & Jan I took quite a lot of Vit D3 to avoid the virulent colds that I was constantly exposed to (about 8,000-12,000iU D3 daily), which seemed to work well to avoid illness (anecdotal, I know, but I’ve been testing this for several years to avoid or diminish severity/length of colds with great success).

    In late January I did a 25 (OH)D test and it came back at 122 ng/mL, the highest I’d ever had. I didn’t haven any problems with a level that high, but I did hold off an any more supplementing until March, when I resumed at 5,000iU D3 daily. In late April my next 25 (OH)D was 68 ng/mL.

    I also make sure I eat foods with natural Vit A fairly regularly (liver pate, “back yard” egg yolks, grassfed butter), or I take some Cod Liver Oil for the A (I can’t get enough Vit D from CLO without getting too much Vit A).

    The only adverse effect I’ve noticed at high doses is perhaps some insomnia if I take Vit D later in the day, which makes sense for a “sunshine” hormone precursor. So I make sure to take it around mid-morning or lunch with some sort of high fat food. If I haven’t remembered to take it by mid-afternoon, I skip it until the next day.

  15. Jamie 20 December 2009 at 1:27 am #

    Nice vitamin D editorial here:

  16. Jackie Bushell 20 December 2009 at 1:28 am #

    Some of our NHS doctors here in the UK may be starting to get the message about Vitamin D, but they sure don’t know what to do about it! When a friend of mine, newly diagnosed with osteoporosis, reported that his GP didn’t want to test his Vit D because ‘we don’t have the drugs to treat it if it’s low’, I was so gobsmacked I had to relate the story in my blog. See the whole disgraceful saga at .

  17. William Trumbower 20 December 2009 at 2:45 am #

    I have a physician collegue who took 50000 units of D3 gelcaps daily for a year. He got severely ill with D toxicity and recquired hospitalization. He did not follow his blood levels and acknowleges that was his problem. If you read Chris Masterson’s work on Vit D and Vit A, he recommends that they be taken together as this decreases the risk of toxicity of both of them. Chris’s works can be found thru the foundation.

  18. Jenny Sanderson 20 December 2009 at 11:27 pm #

    Do vitamin D supplements interfere with breast feeding?

  19. Jamie 22 December 2009 at 2:35 am #

    William – thanks for that reference. Enlightening reading.

    Jenny – no they don’t as very little vitamin D is transferred to breast milk. However, improved maternal vitamin D status does help with milk production & flow rates.

  20. Flannery 1 January 2010 at 10:50 pm #

    My doctor just called in a prescription for Vitamin D and left me a message that my level was critically low at 11. I don’t know how critical he meant, it was just the word he used. I have been having some significant health issues but thus far they don’t know the cause. Is it possible that my Vitamin D level is the cause (or is it more often a symptom of underlying issues?)?

    Sorry for the layperson questions – I don’t know much about D deficiencies.

  21. Nigeepoo 2 January 2010 at 1:59 am #

    Flannery said:
    “Is it possible that my Vitamin D level is the cause (or is it more often a symptom of underlying issues?)?” Either:

    a) Certain health issues deplete the body of Vitamin D.
    b) A lack of Vitamin D in the body causes certain health issues.

    Whichever it is (and I believe that it’s more likely to be b) than a)), you need more Vitamin D!

    Out of curiosity, what dose have you been prescribed? Was it for ergocalciferol or cholecalciferol?

  22. jason 6 January 2010 at 12:31 am #

    My experience with vitamin d seems to be quite a bit different than others. I started taking 800iu of d3 per day after discovering that some symptoms I was having might have had a connection with vitamin d deficiency. Before this, I avoided the sun and got basically no vitamin d at all from my diet, so I didn’t really need a test to know I was deficient.

    After taking that dose for a while and getting out in the sun more often, I went in for a test and was at 23ng/ml. Decided to up the dose to 2000iu’s and felt so tired I could barely move. I’ve never felt so tired in all my life.

  23. DougCuk 13 January 2010 at 11:20 pm #

    Jason – There is a possibility that taking 2000 IU of Vitamin D caused extreme fatigue because you also had a magnesium deficiency. If you try to normalise your Vitamin D metabolism but have very low magnesium levels you will experience muscle weakness and pain. Try combining the Vitamin D with a manesium supplement.

  24. DougCuk 13 January 2010 at 11:35 pm #

    OK that last post should have ended – Try combining the Vitamin D with a magnesium supplement.

  25. Klaus 31 March 2010 at 9:36 pm #

    “I seemed to have reacted badly to the supplement as I have never felt so tired in all my life since taking the vitamin D capsule.”

    Same problem here. I have been diagnosed with a severe vitamin D deficiency (25(OH)D3 6ng/ml). I started taking 5000IU and after the first cap my fatigue has increased a lot. The worst is that this fatigue lasts several days!

    Does anybody have ideas concerning this problem?


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