Image credit: Nature Reviews Cancer
Image credit: Nature Reviews Cancer

The latest newsletter from Dr. Cannell, President of the Vitamin D Council, on vitamin D and the swine flu (and influenza in general).  Well worth reading.

If you are interested in a free subscription to this newsletter, go to the Vitamin D Council site and sign up.

John Cannell, MD
Vitamin D Council Newsletter
May 16, 2009

I have received hundreds of emails from readers, asking what they should do about the possibility of an H1N1 flu pandemic.

Dear Dr. Cannell:

1.    Should I take Vitamin D to prevent the H1N1 flu?  If so, how much?

2.    What role did Vitamin D play in the 1918 pandemic?

3.    If I get this flu, should I take very high doses of vitamin D?  Is so, how much?

4.    Should I take the special flu vaccine the CDC and others are developing?

5.    What are you going to do for your family about the 2009 flu?

6.    Why do the CDC and NIH ignore the Vitamin D studies?

The Public, USA

Dear Public:

First read what I have written about influenza.  Both papers can be downloaded and printed out in their entirety:

Cannell JJ, Zasloff M, Garland CF, Scragg R, Giovannucci E.  On the epidemiology of influenza. Virol J. 2008 Feb 25;5:29.

Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, Garland CF, Giovannucci E.  Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40.

My short executive answers:

1)    Take enough Vitamin D3 to get your 25(OH)D level above substrate starvation levels (50 ng/ml or 125 nmol/L).  Levels of 50 ng/ml usually require at least 5,000 IU per day for adults, some adults will require more.  Children should take 1,000 IU per every 25 pounds of body weight.  After taking this dose for 3 months have a 25(OH)D level.  Individual variation in dose response is great and natural 25(OH)D levels (50-70 ng/ml) are not assured by these doses.  For reasons I will discuss below, I think it possible that Vitamin D levels of 30 ng/ml, which are often obtained by people taking low doses of Vitamin D (1,000 to 2,000 IU/day), may increase your risk of death from a 1918-like influenza virus.

2)    It is clear to me that Vitamin D did not play a controlling role in 1918.  The lethality of the 1918 virus easily overwhelmed innate immunity although I am unwilling to impair my innate immunity by taking inadequate doses of Vitamin D.

3)    Stock you homes pharmacy with several fresh bottles of 50,000 IU capsules of Vitamin D3,  a medicine, not a supplement, and if you get this flu, take 2,000 IU per kg of body weight per day for a week.  As I weigh 220 pounds, I would take 200,000 IU per day for seven days if I thought I had an infection with a 1918-like influenza virus.

4)  Get the H1N1 flu shot as soon as it is available in the fall, especially if the virus shows evidence of lethality this summer in the southern hemisphere,  For reasons I will discuss, a flu shot probably will not generate an immune response in people with 25(OH)D levels above 50 ng/ml but that is simply conjecture.  That is, the flu shot may not work, may not generate antibodies, in people with 25(OH)D levels above 50 ng/ml.  In my opinion, the risk of a lethal virus is higher than the risk of Guillain-Barré Syndrome.  In fact, the risk of Guillain-Barré Syndrome is probably the highest in non-vaccinated people who are infected with the virus and quite low in those who take a modern flu vaccine.

5)   Besides the above actions, stock up on TamiFlu in your home medicine cabinet so you have it next fall and winter.  And follow common-sense precautions, especially frequent hand washing.

6)   Most medically trained physicians, scientists or practitioners think in terms of something bad causing illness, not something good preventing it.  Ask any physician what George Bernard Shaw meant when he said, the characteristic microbe of a disease might be a symptom instead of a cause.  The idea that seasonal influenza or the common cold is a symptom, even the presence of the virus itself being a symptom of an underlying condition, is foreign to modern medical thought.  Influenza researchers at the CDC and NIH think only in terms of vaccines and anti-virals, mainly because most of them have such strong economic affiliations with some aspect of the influenza industry.  The idea of diagnosing and treating Vitamin D deficiency as one part of influenza preparedness is simply foreign to them. Unfortunately, their attitude contributes to the 36,000 deaths every year in the USA from seasonal influenza and leaves American’s innate immune system naked in facing a pandemic.

Detailed answers:

Again, for me to fully answer your questions, and for you to understand my reasoning, the first thing you need to do is to read the articles I have written about influenza.  Neither article is about pandemic influenza, rather epidemic influenza.  Both are full access articles.

Cannell JJ, Zasloff M, Garland CF, Scragg R, Giovannucci E.  On the epidemiology of influenza. Virol J. 2008 Feb 25;5:29.

Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, Garland CF, Giovannucci E.  Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40.

Next is to read additional papers on our website.  We have attempted to get full copies of the most important articles when possible:

Vitamin D Council/Science/Influenza

The WHO reports:

“H1N1 appears to be more contagious than seasonal influenza. The secondary attack rate of seasonal influenza ranges from 5% to 15%. Current estimates of the secondary attack rate of H1N1 range from 22% to 33%.  With the exception of the outbreak in Mexico, which is still not fully understood, the H1N1 virus tends to cause very mild illness in otherwise healthy people. Outside Mexico, nearly all cases of illness, and all deaths, have been detected in people with underlying chronic conditions.

In the two largest and best documented outbreaks to date, in Mexico and the United States, a younger age group has been affected than seen during seasonal epidemics of influenza. Though cases have been confirmed in all age groups, from infants to the elderly, the youth of patients with severe or lethal infections is a striking feature of these early outbreaks.  In terms of population vulnerability, the tendency of the H1N1 virus to cause more severe and lethal infections in people with underlying conditions is of particular concern.”

Virologists are concerned with three aspects of any influenza virus: (1) novelty, (2) transmissibility, (3) lethality.  The current H1N1 is novel, that is, we have no antibodies to this strain.  Its transmissibility is high but its lethality (percent who die after infection) is still low, except in Mexico.  Why it was so lethal in Mexico, no one knows.  Will that lethality return as the virus mutates this summer?  Keep in mind that the lethality of the 1918 flu was high, perhaps a billion people infected, a half billion became ill, and, at the most, one tenth of a billion died.  Until the 2009 virus exposes its lethality, and it may not do so until next fall or winter, we are all playing an involuntary game of Russian roulette.

Pandemics imply widespread infection thus transmissibility, but do not specify the virus’s lethality.  However, this virus was transmitted in May, near the equator, at 7,000 feet altitude.  May is the time influenza transmission usually stops because population 25(OH)D levels are rising quickly. Lethality of influenza viruses change over short periods of time (weeks to months).

That is, the WHO and CDC have no way of knowing if this virus will acquire lethality.  Lethality is how quickly this virus will bore holes in your lung cells, hijack that cells genetic machinery, burst the cell, and spew out hundreds of thousands of swarming viruses to do the same thing to the next respiratory cell, perhaps triggering a cytokine storm response by your body’s immune system that quickly strips your lungs of the cells you need to breath.

If that does not kill you within a few days, it leads to pneumonia, the “Captain of the Men of Death,” who finishes the job in a few weeks.  Some viruses, even novel ones, even novel pandemic ones, are not very lethal.  The 1918 virus was an expert driller and was thus highly lethal, but it was its transmissibility combined with lethality that lead to the massive deaths.  It was able to eventually infect about half the world, maybe more; its combined lethality and transmissibility showed itself during its second wave, the autumn wave of 1918.  The Asian pandemic of 1957 started mild, and returned in a somewhat more severe form the following winter. The 1968 Hong Kong pandemic began relatively mild and remained mild in its second winter wave in most countries.

Dear Dr. Cannell:

How does Vitamin D work in the immune system?

Philip, Texas

Dear Philip:

Two systems exist in your body to fight infections, the innate or immediate system and the acquired or adaptive immune system that makes antibodies.  Recent evidence indicates seasonal impairments of the antimicrobial peptide (AMPs) systems are crucial to impaired innate immunity, impairments caused by seasonal fluctuations in 25-hydroxy-vitamin D [25(OH)D] levels.  The evidence that vitamin D has profound effects on innate immunity is rapidly growing.

Janet Raloff. The Antibiotic Vitamin, Science News

Unlike adaptive immunity, innate immunity is that branch of host defense that is “hard-wired” to respond rapidly to infections using genetically encoded effectors that are ready for activation by an antigen before the body has ever encountered that antigen. Of the effectors, the best studied are the antimicrobial peptides (AMPs).

Both epithelial tissues and white blood cells produce AMPs; they exhibit rapid and broad-spectrum antimicrobial activity against bacteria, fungi, and viruses. In general, they act by rapidly and irreversibly damaging the lipoprotein membranes of microbial targets, including enveloped viruses, like influenza.

Antimicrobial peptides protect mucosal epithelial surfaces by creating a hostile antimicrobial barricade. The epithelia secrete them constitutively into the thin layer of fluid that lies above the apical surface of the epithelium but below the viscous mucous layer. To effectively access the epithelium, a microbe must first infiltrate the mucous barrier and then survive assault by the AMPs present in this fluid. Should microbes breach this constitutive cordon, their binding to the epithelium rapidly mobilizes the expression of high concentrations of specific inducible AMPs, which provide a backup antimicrobial shield.

The crucial role of vitamin D in the innate immune system was discovered only very recently. Both epithelial cells and macrophages increase expression of the antimicrobial cathelicidin upon exposure to microbes, an expression that is dependent upon the presence of vitamin D. Pathogenic microbes stimulate the production of an enzyme that converts 25(OH)D to 1,25(OH)2D, a seco-steroid hormone. This in turn rapidly activates a suite of genes involved in pulmonary defense.

In the macrophage, the presence of vitamin D also appears to suppress the pro-inflammatory cytokines. Thus, vitamin D appears to both enhance the local capacity of the epithelium to produce endogenous antibiotics and at the same time dampen certain destructive arms of the immune response, especially those responsible for the signs and symptoms of acute inflammation, such as the cytokine storms operative when influenza kills quickly.

Because humans obtain most vitamin D from sun exposure and not from diet, a varying percentage of the population is vitamin D deficient, at any time, during any season, at any latitude, although the percentage is higher in the winter, in the aged, in the obese, in the sun-deprived, in the dark-skinned, and in more poleward populations. However, seasonal variation of vitamin D levels even occur around the equator and widespread vitamin D deficiency can occur at equatorial latitudes, probably due to sun avoidance, rainy seasons, and air pollution.

For example, a study of Hong Kong infants showed about half had 25(OH)D levels less than 20 ng/ml in the winter. Even in the summer, few of the infants had levels higher than 30 ng/ml, which many experts now think is well below the lower limit of the optimal range. As 25(OH)D levels affect innate immunity, then a varying percentage of most populations even equatorial ones will have impaired innate immunity at any given time, together with distinct seasonal variations in that percentage. The effects such impairments have on influenza transmission are unknown.

Dear Dr. Cannell:

Will Vitamin D protect me against acquiring the H1N1 flu?

George, Utah

Dear George:

I don’t know; no one does.  I am concerned about people who take low doses of Vitamin D (1,000 – 2,000 IU/day) and only achieve a 25(OH)D blood level of 30 ng/ml.  If the virus mutates into a virus as lethal as the 1918 virus, I doubt Vitamin D will totally protect you. Several facts about the 1918 pandemic concern me.

1. Blacks were less likely to contract the flu or die from the flu than whites in 1918.

2. Young people, presumably with the highest 25(OH)D levels, were the most likely to die in 1918, as they have been in Mexico to date.

3. In October of 1918, the Spanish flu erupted simultaneously in both Northern and southern hemispheres.

4. Significant deaths occurred in the Northern hemisphere during the summer of 1918 although the extraordinary killing erupted in October of 1918 in the Northern Hemisphere.

5. One of the worst affected countries was Western Samoa. A crippling 90% of the population was infected; 30% of adult men, 22% of adult women and 10% of children were killed.  This devastation occurred during their summer.  I doubt 90% of the population of Western Samoa had levels below 50 ng/ml in 1918 but I have no way of knowing.  More likely, the population had little acquired immunity to any influenza virus.

Jordan EO: Epidemic Influenza, a survey. Chicago: American Medical Association; 1927. [you’ll have to follow the links to get to this one]

After rereading Jordan, I doubt vitamin D was the controlling factor in the 1918 Pandemic.  Furthermore, some of the above data – highest death rates in whites and young adults suggests having some vitamin D was a risk factor for death.  Thus, take enough Vitamin D.

However, other facts suggest Vitamin D was protective in 1918:

1. The mass of deaths in the Northern hemisphere occurred when Vitamin D levels were low (fall and winter).

2. While infection rates were similar for sailors and troops on infected troop transport ships, the sailors had 1/4 the mortality of the troops.  One has to assume the 25(OH)D of sailors aboard 1918 troop transport ships was higher than the troops inside.

3. Underground coal miners in North America had the highest mortality of any occupation.

4. The incidence of influenza in the French army was much higher in troops away from the front (probably in barracks) than in front line troops.

5. Open air hospitals in North America allegedly had lower mortalities than regular hospitals.

6. Mortality for sailors at sea was markedly lower than sailors ashore, despite the crowed conditions on board.

7. In the Western Front, the 1918 flu disappeared in August (when 25(OH)D levels reach their peak) only to return in September, when 25(OH)D levels fall rapidly.

My best guess is that 5,000 IU/day and a 25(OH)D of > 50 ng/ml will be at least partially protective.  Remember, at 50 ng/ml, you are assured that you are not suffering from substrate starvation, that is, your body has enough Vitamin D for its needs and some left over to store.  At a level of 30 ng/ml, most people are still suffering from Vitamin D substrate starvation.

Heaney RP, Armas LA, Shary JR, Bell NH, Binkley N, Hollis BW. 25-Hydroxylation of vitamin D3: relation to circulating vitamin D3 under various input conditions. Am J Clin Nutr. 2008 Jun;87(6):1738-42.

As I have written before, 25(OH)D levels are like water from a mountain spring.  The topmost pool is the calcium economy.  When that pool is full, excess 25(OH)D flows down to hundreds of pools below, cancer, heart disease, infection, etc.  In a lethal pandemic, you want Vitamin D to do two things, increase production of natural antibiotics (AMPs) and quell excessive immune responses.  Are these two pools at the same level?  Is the AMP pool above the cytokine dampening pool?  If so, people with 25(OH)D levels of 30 ng/ml may have enough D to strengthen their innate immunity but not enough to prevent the cytokine storm that kills in a lethal pandemic.  Thus, people taking only 1,000 – 2,000 IU/day, with levels around 30 ng/ml, may risk death from a cytokine storm their body is unable to prevent.  While only a theory, it would explain why the people with the allegedly highest 25(OH)D levels in both Mexico and 1918 (young adults) were the most likely to die.  That is why I caution people that, if you are going to take Vitamin D, take enough, take 5,000 IU/day, which is usually enough to get your 25(OH)D levels into the mid range of the reference range (30-100 ng/ml), which would be 50-70 ng/ml.

Dear Dr. Cannell:

Will this H1N1 flu reappear next fall?

May, Washington DC

Dear May:

Million dollar question!  Flu viruses constantly mutate.  Right now it lacks an amino acid sequence that confers lethality.  Will it acquire that amino acid by next fall?  I don’t know and if anyone one tells you they know then you know a fool.

Dear Dr. Cannell:

Will you and your family take the flu shot they are developing?

Jerry, North Carolina.

Dear Jerry:


However, it will probably not do much as it may be unable to generate an immune response in those with high 25(OH)D levels.  Two Russian studies, the only such studies in the world, suggest higher vitamin D levels prevent the immune response flu shots attempt to generate.  Dr. Scott Dowell, at the CDC, has known about these two studies for at least five years.

In 1977, Russian scientists inoculated 834 non-immune males with live attenuated influenza virus in St Petersburg (62 N) and Krasnodar (45 N), Russia during different seasons of the year, comparing them to 414 vehicle placebo controls. In St Petersburg, they found that the attenuated virus was about eight times more likely to cause physical evidence of infection (fever) in the winter than the summer (6.7% vs. 0.8%). In Krasnodar, 8% of inoculated subjects developed a fever from the virus in January, but only 0.1% did so in May.

Shadrin AS, Marinich IG, Taros LY. Experimental and epidemiological estimation of seasonal and climatogeographical features of non-specific resistance of the organism to influenza. Journal of Hygiene, Epidemiology, Microbiology, and Immunology 1977; 21: 155161.

Different Russian scientists found that fever after inoculation with attenuated virus was twice as likely in February (10.7%) as in June (5%), compared to vehicle placebo controls. They also confirmed that sero-conversion varied by season, with the lowest rate of antibody formation in summer. When they attempted to recover the virus 4872 h after inoculation, they found subjects were more likely to shed the virus in December (40%) than in September (16%), and the quantity of virus shed was significantly lower in summer than winter.

Zykov MP, Sosunov AV. Vaccination activity of live influenza vaccine in different seasons of the year. Journal of Hygiene, Epidemiology, Microbiology, and Immunology 1987; 31: 453459.

These two studies suggest higher Vitamin D levels may prevent a vaccine from causing an immune response, the whole idea of a vaccine.

Dear Dr. Cannell:

What about Guillain-Barré Syndrome if I take the flu shot?

Jeanne, California

Dear Jeanne:

Influenza or influenza like illness usually precedes the autoimmune process of Guillain-Barré Syndrome.  Thus, a recent study found a seven-fold risk for those who contracted the flu but a slightly decreased risk for those getting a modern vaccine.

Stowe J, Andrews N, Wise L, Miller E. Investigation of the temporal association of Guillain-Barre syndrome with influenza vaccine and influenza-like illness using the United Kingdom General Practice Research Database. Am J Epidemiol. 2009 Feb 1;169(3):382-8.

This appears to be much different than the 1976-77 swine flu experience, the last time a swine flu virus caused this type of consternation.  Then, the vaccine was associated with a seven-fold risk of Guillain-Barré Syndrome, but the feared pandemic never materialized.  That is, as Guillain-Barré Syndrome is a complication of the flu and the flu failed to materialize that year, we will never know what the risk of Guillain-Barré Syndrome would have been in 1978 in those who got the flu but no flu shot.

Safranek TJ, Lawrence DN, Kurland LT, Culver DH, Wiederholt WC, Hayner NS, Osterholm MT, O’Brien P, Hughes JM.  Reassessment of the association between Guillain-Barré syndrome and receipt of swine influenza vaccine in 1976-1977: results of a two-state study. Expert Neurology Group. Am J Epidemiol. 1991 May 1;133(9):940-51.

As Guillain-Barré Syndrome is an autoimmune process, those on 5,000 IU per day should not have to fear it.

Dear Dr. Cannell:

Why does the CDC and WHO ignore all the work on Vitamin D and flu?

Sally, California

Dear Sally:

I’m not sure.  A randomized placebo controlled trial showed vitamin D prevents colds and flu.

Aloia JF, Li-Ng M. Re: epidemic influenza and vitamin D. Epidemiol Infect. 2007 Oct;135(7):1095-6;

However, when these same authors attempted to reproduce their findings by giving 2,000 IU/day for four months, they found no protective effect of Vitamin D.

Li-Ng M, Aloia JF, Pollack S, Cunha BA, Mikhail M, Yeh J, Berbari N. A randomized controlled trial of vitamin D3 supplementation for the prevention of symptomatic upper respiratory tract infections. Epidemiol Infect. 2009 Mar 19:1-9.

However, these same authors have since concluded that 2,000 IU/day for four months is an inadequate dose and 5,000 IU per day is generally required to assure 95% of the population has adequate levels.

Aloia JF, Patel M, Dimaano R, Li-Ng M, Talwar SA, Mikhail M, Pollack S, Yeh JK. Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration. Am J Clin Nutr. 2008 Jun;87(6):1952-8.

At least 5 studies show an inverse association between lower respiratory tract infections and 25(OH)D levels or sunshine.  That is, the higher your 25(OH)D level, the fewer colds and flu:

Laaksi I, Ruohola JP, Tuohimaa P, Auvinen A, Haataja R, Pihlajamäki H, Ylikomi T.  An association of serum vitamin D concentrations < 40 nmol/L with acute respiratory tract infection in young Finnish men. Am J Clin Nutr. 2007 Sep;86(3):714-7.

Karatekin G, Kaya A, Salihoğlu O, Balci H, Nuhoğlu A. Association of subclinical vitamin D deficiency in newborns with acute lower respiratory infection and their mothers. Eur J Clin Nutr. 2009 Apr;63(4):473-7.

Ginde AA, Mansbach JM, Camargo CA Jr. Association between serum 25-hydroxy-vitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009 Feb 23;169(4):384-90.

Wayse V, Yousafzai A, Mogale K, Filteau S. Association of subclinical vitamin D deficiency with severe acute lower respiratory infection in Indian children under 5 y. Eur J Clin Nutr. 2004 Apr;58(4):563-7.

Termorshuizen F, Wijga A, Gerritsen J, Neijens HJ, van Loveren H. Exposure to solar ultraviolet radiation and respiratory tract symptoms in 1-year-old children. Photodermatol Photoimmunol Photomed. 2004 Oct;20(5):270-1.

Despite these studies, the scientists at CDC and WHO are thinking only in terms of a vaccine or TamiFlu.  The idea of strengthening the innate immune system with Vitamin D is simply not on their radar.  Many of these scientists have financial connections to the influenza industry.  However, It is not a conspiracy.  When I was young, I thought most things were conspiracies.  Now that I am older, I know it is not a conspiracy, only incompetence.

If this virus mutates this summer and acquires more lethality and maintains its transmissibility, we may experience another 1918 pandemic.  If so, I plan to be fully armed, with both Vitamin D and the best modern conventional medicine has to offer.

John Cannell, MD
Vitamin D Council

This is a periodic newsletter from the Vitamin D Council, a non-profit trying to end the epidemic of vitamin D deficiency.  Please reproduce it and post it on Internet sites.  Remember, we are a non-profit and rely on donations to publish our newsletter and maintain our website.  Send your tax-deductible contributions to:

The Vitamin D Council
585 Leff Street
San Luis Obispo, CA 93401

Image from Nature Reviews Cancer


  1. Interesting thought that Vitamin D so significantly aids the body’s defence response against flu. I would imagine that people in Mexico are exposed to more sunlight than those of us in the North of the US and UK/Europe – so it is curious that the virus should be so much more lethal to Mexicans.

    Great article.

  2. Chris,

    Dr. Cannell of the Vitamin D Council ( has a newsletter up now that touches on this very issue of cytokine storms and how it relates to Vitamin D status.

    One thought I had was that children and young adults might be more susceptible due to indoor schooling and employment (factories, offices, etc.), resulting in *less* midday sunshine exposure, therefore have lower 25 (OH)D levels than many older adults.

  3. My wife came down with a severe sore throat (with white spots) just before we were to leave on a overseas trip two weeks ago. Goggling sore throats I learned she had a viral sore throat or even step throat. Having no time to go to a doctor, I remembered his stoss therapy on the Vitamin D Council web page.

    So she took 150,000 units a day for three days. The sore throat lessened on the first day of treatment and was completely gone by the third day. She had no side effects from the stoss therapy.

    Her Vitamin D level was 68 before her treatment so I imagine her Vitamin D level went pretty high temporarily but she had no problems.

  4. Dr. Cannell states that taking low doses of Vitamin D (1,000 to 2,000 IU/day), may increase risk of death from a 1918-like influenza virus. Is he implying that we are better off taking none if we don’t take at least 5,000 IU daily?

    That’s what it sounds like to me.

  5. I may be misremembering this about Dr. Linus Pauling. He was the megadose vitamin C advocate and took a stab at immunity to the common cold from mega doses of Vitamin C.

    The part that I may be misremembering is that he felt confident in the vitamin C – common cold connection because he had read of some kind of study where Scandanavian ski instructors who took vitamin C mega doses had fewer colds.

    It is a small step from there to the sunshine environment of ski instructors generating abundant winter vitamin D…… and maybe whatever small effect there was associated with cold and vitamin C was being confounded by the Sunshine factor unique to this sub-population and the high Vitamin D levels which might be thereby generated.

    Perhaps Pauling should have spread out his mega vitamin letters a little bit, and could have had greater success.

    Perhaps today a study of northern ski instructors would show up extra healthiness and some fraction of that healthiness may be vitamin D of the sun generated type. Naturally.

    1. And vice versa; perhaps vitamin C fills some of the holes in the flu-vitamin D link; sailors would have been supplemented with vitamin C (from citrus) in 1918, the rest of the European population would have been in semi-scurvy, due to naval blockades and rationing.
      Combine low Vit C (very low by todays standards, when ascorbate is even an antioxidant in junk food) with low vit D and a new virus, you have the perfect storm of 1918.
      They have recently shown that low mega-dose vit C does protect against colds in cold climates, so Pauling was right about the skiers.

  6. I’d like to add to Anna’s wonderful insights (as usual *WINK*)… Most people of darker-toned skin have inherent protective mechanisms from melanin (skin pigmentation) that block the actions of UV radiation, including UVB activation of vitamin D in the skin. I was completely surprised to find that my vitamin D blood level was only 20 ng/ml at the end of a summer where I was outdoors with my kids by the pool nearly every other day (in a two-piece + sunscreen SPF50) for HOURS.

    I don’t think it would be shocking at all to see epidemic vitamin D deficiency in Mexico and Texas, and more pronounced in inviduals of darker-toned skin! What I observe in the int med arena is that > 80 % of vitamin D lab results are deficient [25-OH-D] < 30 ng/ml irregardless of ethnicity, age, or gender.

    Quite scary indeed, more than H1N1.

  7. the antiviral effects of vitamin D are clear in the literature. WOuld be interesting to hear from some herpes suffers if they have had an effect from increasing their vitamin D levels. Here is a good site, The site also offers a good newsletter

  8. Dr. Eades,
    What do you think of the pneumonia vaccine? Could this vaccine help prevent the flu turning into pneumonia?

    Not really. The pneumonia vaccine vaccinates against a specific bacterium that causes a serious type of pneumonia common in elderly people. It would prevent this type of pneumonia, but not the pneumonia caused by the influenza virus.

  9. For those who might still be concerned, esp if their D levels are low…the current ‘swine’ flu is a lipid-enveloped virus. The lipid surround can be dissolved by consuming 1-3 tablespoons of coconut oil (the healthy kind that melts at 72 degrees, organic). Coconut oil contains a particular fat that the body converts to monolaurin which it then uses against pathogens. Lots of research/info out there; search for Mary Enig’s articles, ignore anything by Ancel Keys as his testing in the ’50s used hydrogenated coconut oil and he was in the pay of the veggie & seed oil interests.

    Hey Doc, how do we get bottles of 50K IU of D3? I’ve not seen them in health food stores. Thanks.

    You can find 50K IU vitamin D3 in the products section of our website. I’m sure you can find them other places online as well, but I don’t know any other specific sites.

    The lauric acid in coconut oil is an immune booster, but I’m not sure it would prevent the flu in most cases.

  10. As high strength D3 supplements are not available over the counter in the UK may I remind UK readers that
    BIO-TECH Pharmacal Inc.
    are the source recommended by Dr Cannell from his site The Vitamin D Council.
    For those interested in STOSS therapy mentioned above they are the cheapest source of 50,000iu online to the UK. Be aware Customs duty is charged on orders £18 or more and Post Office charge £8 to collect the tax. Ordering by phone from the UK may be an idea. Charge $40 for postal 25(OH)D testing to ensure you achieve the 50ng~70ng Dr Cannell suggests.

  11. In his answer to #1, should the sentence, “For reasons I will discuss below, I think it possible that Vitamin D levels of 30 ng/ml, which are often obtained by people taking low doses of Vitamin D (1,000 to 2,000 IU/day), may INCREASE your risk of death from a 1918-like influenza virus.”

    Shouldn’t “increase” be “decrease”? Or am I reading this wrong?

    You are reading it wrong. INCREASE is the correct word.

  12. Great info – I have subscribed to the newsletter.

    I just got my vitamin D test back. 29. And I am a SERIOUS sardine muncher and recent sun-worshipper, albeit in the UK climate. More detail on the background in my blog post about it.

    My Vitamin D Deficiency – a Salutary Lesson

    I am now trying to bully my nearest and dearest into getting tested!

  13. Mike, the site that you reference is in the business of selling D3.

    Not that the information is inaccurate, bad or deceptive, but it is certainly biased toward getting you to purchase this stuff so as to avoid dying prematurely of {fill in the blank} disease/deficiency/creeping crud.

    Maybe you want to buy from them, but you certainly don’t want to trust their information as conclusive.

    Stick with clinical and physiological studies. Avoid the demographics.

    Jim B: Ski instructors getting enough vitamin D? According to the vitamin D3 world site, that would not be possible. Skiers are covered from head to toe (including goggles – even back then we wore goggles – I was a ski-patrol skier for years in Vermont), with only their faces exposed, in a climate where the sun is always low on the horizon compared to the Southwest US. There was just a bit more to Linus Pauling’s advocacy of Vitamin C than some average Joe having ‘read a study’. Also, he was not in the business of selling Vitamin C.

    Sure, I agree that we do NOT get enough Vitamin D as most of us basement dwellers aren’t let out during the day (I loathe milk), so I’ll take D, AND C and benfotiamine.

    Advocacy is not a bad thing. But it is always suspect when there is financial gain behind it. If you are suspicious of pharmaceutical companies that hock statins, then you should at least be as suspicious of ‘vitamin pushers’ with a $$ stake (although they are less likely to kill you ;->)

    I disagree. The Vitamin D Council is a non-profit organization that constantly struggles for funding. Most of their income comes from donations. They sell a few products, but nothing much to speak of.

    I have to say, though, if you’re going to purchase something from their site, avoid the book they tout. I’ve got to blog on it at some point. I think it’s terrible.

  14. Mike, there are a bunch of folks pushing Vitamin remedies for herpes online, including Vitamin D and Vitamin C. I just did a quick google search, not a comprehensive troll. You might find that someone has done just what you suggest.

    My current quandary is whether boosting my immune system will also boost my allergy symptoms. I suppose I should go do some more research now…

    Based on my n=1 (me), allergies do not worsen when one cranks up the vitamin D3.

  15. g- why would you be surprised that your levels were so low when you had on a coating of SPF 50? I would imagine you would know better if you read Protein Power Lifeplan…

    Dr. Eades,
    I shouldn’t take 5,000 IUs Vit D3 on the days I lay out in the sun– no sunscreen/sunblock of course –right? Any day there is sun I’m out in it long enough to get my Vitmain D without burning. (benefit of being a stay at home mom!)

    Also, would my Dr. write up a prescription of Tamiflu for me to have on hand to “stock up” my home pharmacy as Dr. Cannell suggests? I’m doubting that…

    I don’t take vitamin D on the days that I’m out in the sun in the summer. The sun doesn’t do a lot in the winter, so I take it then even when I do go out in the sun.

    Some docs will write scripts for Tamiflu when people without the flu ask for it – others won’t.

  16. I may have missed it, but are there any randomized, double masked controlled clinical trials to show that taking 5000 IU or more of Vitamin D3 really lowers the incidence, duration and severity of upper respiratory tract infections? It seems that, from the list of studies mentioned above, most of the studies claiming a benefit from taking Vitamin D3 are just observational ones and that the randomized, double masked controlled trial mentioned in the list only found that there was no difference in symptoms between a group taking 2000 IU/day and placebo.

    I noticed that, too. I suspect that a difference would have been seen with higher daily vit D doses, but I can’t say for sure. Right now most of the studies out there on vit D are observational. I’m sure a bunch of RCT are in the works, though.

  17. If you think about how much time people are indoors compared to in the paleolithic era… it kinda makes since that 80 percent of any population would have low levels. I also swear that the sun is what heals my acne completely during the summer (unfortunately I can seem to get around the fact the it always comes back in the fall) because of the stimulation of antimicrobial peptides.

    “When you optimize your vitamin D levels you make over 200 antimicrobial peptides (also called host defense peptides). They are an essential component of your innate immune response, and are potent, broad spectrum antibiotics.” -Dr. Joseph Merola

    So it has an antimicrobial and antiviral effect…
    Yeah, it just a coincidence we get sick in the winter… oh and that holiday carbfest has nothing to do with is either.

  18. Oh… and one question. Vitamin D is accurately measured in your blood? (Is it not like magnesium where your tissue and neurons contain most of the the ca and magnesium that can then be leeched into your blood to maintain those levels… AKA you can have a decent blood level but can still be deficient?)

    Nope, blood levels of 25(OH) vit D tell the tale.

  19. Chris,

    have you ever been to Mexico City (or D.F., as they call it there)? It is so covered with smog that you hardly ever get to see the sun. I have relatives there (+ have been there myself). They say that the children there never use blue colored pencils for drawing the sky … They don’t know what a blue sky is. Plus, the city is located very high and the air is thing and lacking oxygen as it is. Hardly any adult in Mexico City has a completely healthy respiratory system.

    No wonder that all swine deaths in Mexico occurred in its capital.

  20. This article is really helpful for me and for all of us. Vitamin D is really needed in our body. Our body will not be complete without vitamin D, because it helps fight back influenza and I know many people died of influenza few years back, and now H1N1, which death toll increases and the list of countries affected are also increasing of thid deadly virus.

  21. Dr. Eades,

    Recently I built my son a lizard cage. He caught a small Anole (chameleon) and placed it proudly in his cage. The lizard has thrived, and eats any insect we throw into the cage (which thrills my 7 year old XY). Catching and finding insects has been a bit of a pain, so we went to the pet store and acquired a cricket holder and a batch of crickets. The clerk at the store pressed us to also buy a supplement powder that we were supposed to sprinkle on the crickets, otherwise the animal would allegedly become frail, sick and die. I was a bit skeptical, so I read the label on the supplement….turns out the supplement is 25-OH vitamin D3.

    Things that make you go hmmmm.

    Doug McGuff, MD

  22. hi Doc
    after all the learned discussion of the matter i cannot understand why the obvious solution is not encouraged. it seems to me that the most effective and economical way for people to upgrade their vitamin D status is to maximise skin exposure andthe body’s ability to make its own vit D by practicing nude sunbathing.


    I agree. And I volunteer to be the proctor to make sure everyone is complying. 🙂

  23. Most of the deaths in Mexico were in Mexico City. I’m not sure that they get that much sunlight, with all the smog and the dense building shadows, the subway, etc.

  24. Hi Dr Mike! Whats going on in California? Fires and now earthquake? Come here in NY!

    Dr Mike, when I go to my doctor and ask him to do Vit D test, is it Vit D am checking? Also what brand and what amount whould u recommend for a pale skinned Russian from Syberia like me? What would be a good amount? Is it vit D I am supposed to be buying or do they sell them in one form only? Thanks a million as usual! Be well!

    The test you need to get is 25(OH)vitD. That is the only one that accurately measures the levels you need measured. A good amount is the amount needed to bring you up to the 50-80 ng/ml range. If you’re low, start with 5,000 IU per day. Get vitamin D3.

  25. Every statement on that site is linked to an original reference on pub med. just because they are selling something does not invalidate the data, try reading it for yourself, you might be surprised. I also noticed they have just started offering free vitamin D for children, dont see anyone else doing that do you!

  26. To Ted Hutshinsons concern about UK customs, just tell the customes to send note to the supplier asking them to only declare wholesale value on the customs form as most do and you dont run into a problem

  27. Off topic but I thought you and your readers might be interested in a company I found in CA that makes protein powders to specifications. You can choose type of proteins, flavors and sweeteners including stevia or have it unsweetened if you’d like. You can even choose to add amino acids to the mix. Prices are very inexpensive due to lack of marketing and advertising. I am very happy with my first order of an unsweetened protein blend in chocolate. It was a little mild for my taste but I understand you can order double flavoring at no additional charge which I will do next time. I read on the site that when unsweetened chocolate is specified, only real cocoa powder is used. Site:

    Dr. Mike, I tried to post this info on twitter but don’t know what I’m doing there yet so I apologize if you got a strange ‘tweat’ from me.

    Don’t worry. I’m clueless, too.

  28. Do you or the Mrs please know how much roughly we assimilate from say a 1000iu of Vit D3 please ?

    I would imagine most of it.

  29. Wonderful post Dr. Eades!


    I mentioned the SPF b/c that’s what we’re told in the U.S. to do and probably contributed to the deficiency somewhat. What I failed to mention was that I was in the sun sweating (a lot) and swimming (no re-applying) which rinses SPF off. 🙂 Good point though!

    One of my patients is a nudist — totally tan in his 50s — totally vitamin D deficient < 40 ng/ml. Happens to SPF-free people too. In fact it’s a given. (he consumes wheat still too — Cordain has data wheat contributes to inactivation of vitamin D at the skin level; btw I wasn’t wheat/gluten free when I was dx’d with vit D deficiency)


  30. The test you need to get is 25(OH)vitD. What is the difference between this and 1.25 vitamin D? How are they related, if at all. Also, when taking D3 in doses of 5,000 and above should it be taken all at once, or spread out over course of day such as with meals. Thanks.

    25 (OH) D is the test you want. The second one you mentioned is active vitamin D and changes too quickly to give reliable lab results. You can take the 5,000 IU of Vit D all at once. It doesn’t have to be spread out.

  31. Nobody has mentioned the fact that if you shower after sunbathing, you may be washing off all the Vit D before it has a chance to be absorbed. Dr. Cannell states:

    “These last two studies raise the possibility that sunbathing or using UV lights may not produce much vitamin D if you shower with soap after exposure. Water cleans the body but does not destroy as much sebum, human body oil. When you think about it, God made the perfect body oil for humans—sebum—but humans wash off her body oil and then apply body oils made by the cosmetic industry. I doubt she likes that.”

    I saw the reference to the two articles, but it wasn’t a full reference, so I couldn’t find them. Unless and until I read something that proves to me conclusively that this is true, I tend not to really believe it.

  32. Martin & Dr. Mike –

    Given the physical stature of a LARGE portion of the US population, I beg of you to re-consider the wisdom, and appearence, of large-scale nude sunbathing …

  33. Dr. McGuff,

    My 10 yo often keeps little lizards he catches in the backyard, feeding insects, too. We use a terrarium full-spectrum light, which is very important for lizards and their Vit D production. Vit D deficiency is well-known in herpetology circles.

    I finally sent the backyard lizards back outside, though, when they grew to the point they were costing me more in weekly live cricket expense than the cats with their homemade ground whole chicken & organ food. Now we keep amphibious salamanders/newts, which can eat the [free] red wiggler compost worms.

  34. Dear Dr,

    I posted this in another of your blog post on 23rd April and it is still awaiting moderation. Anyway, Dr here is the query.

    Dr Mike,

    This morning (Apr 23rd) I received the lab work results and all are good. Only the Uric acid has increased from ~5.5 to 8.0. I am a Type II Diabetic, Male, 38 years old. I consume ~40g net carbs everyday.

    The Dr was asking me to be cautious on the uric acid levels else I will have Kidney/heart problems later. I am not sure what I can do to control my uric acid levels. Other than this one, everything else is in perfect order thanks to your Low Carb service .

    Please let me know.





  35. Hey doc
    Do you have the reference for that nature reviews paper the image is from?
    Just curious


  36. Someone make the comment that mexicans get more sun so its surprising the virus is more potent there-no so. It has been shown that even in sunny areas folk are still deficient as we do so much to keep us covered up. There are several studies in the arab countries showing they are 100% deficient due to their custom of keeping covered from head to toe. Take a look at The site also has a good newsletter and presently is offering free supplies of vitamin D to its customers children

  37. @Mike

    In latest news, correlations have been found between sombrero wearing and vitamin D deficiency…

    No that’s not true (though it could be), but think of the headlines.

  38. “For half a century, medical science has been noting the association between vitamin D serum levels and disease. What developed has been a concept of ‘vitamin D deficiency’ based solely on the assumption that low vitamin D serum levels somehow cause disease processes

    that the observed serum levels are modified by disease processes—is far more plausible than the currently accepted ‘vitamin’ pragma—that the lower levels observed in sick individuals are indicative of a nutritional deficiency […]

    (Because of fortification)
    It is thus very difficult to find a population which can be studied in order to ascertain what the level of natural metabolic homeostasis for 25-D might actually be. These studies show a wide variation in levels of 25-D being generated by populations whose diets have probably not yet been significantly altered by ‘The Sunshine Vitamin,’ indicating that the unsupplemented metabolic homeostasis is probably in the range 23–60 nmol/L, and that it falls with advancing age[…]
    Surely we are being naive if we expect the exogenous modulation of a metabolism that is responsible for the expression of over a thousand genes to provide a simple go/no-go result?”

    During summer, we accumulate vitamin D3 and store it, so that supplies for vitamin D do not become completely depleted during the winter months. Within three days of a dose of vitamin D3, very little of the original vitamin D is detectable in plasma of rats (101) or humans (102). Most vitamin D entering the circulation appears to be excreted unmetabolized into the bile.[…]

    If 30,000 years after entering northern Europe natural selection hasn’t changed this (as it easilly could). I wonder if the reason isn’t that the Vitamin D requrements are met, and then some, by North European sunshine.

    If one looks at the system of vitamin D metabolism in Figure 2 from the perspective of a system designed to control something, it becomes clear that this is a system better designed to cope with an abundance of supply, not a lack of it. The flow of vitamin D toward 25(OH)D is remarkably inefficient, with most bypassing it. Furthermore, there is no way to correct for deficiency of vitamin D, other than to redirect utilization of 25(OH)D toward 1,25(OH)2D production, which is the pathway most acutely important for life. That is, when supplies of vitamin D are severely restricted, its metabolism is directed only toward the maintenance of calcium homeostasis. To expand on the point that the system of vitamin D metabolism is effectively designed for adjusting for higher inputs, not lower inputs, I offer the example of an air-conditioner system. Air conditioners are designed to compensate for excessive heat, but they are a useless way to compensate for a cold environment.”

    This points towards a natural homeostasis of vitamin D synthesis and storage in northern Europe that has not modified from the one evolved in Africa because it’s still dealing with an excess.

  39. Dr Mike,
    Do you think 5,000 mg of D3 is o.k. during pregnancy? I also try to sit in the sun when I can but this is often irregular.

    I don’t think it’s a problem, but you ought to check with your own physician.

  40. G- I haven’t heard about the connection with wheat consumption and Vit D deficiency! Hmmm.

  41. My understanding is that flu loves dry climates & mexico city is very dry relative to much of the US which has been experiencing rising humidity with the onset of spring and summer. Flu is much more prevalent when and were its dry.

  42. There is a (controversial) article about Vitamin D which explains well the behavious of Vitamin D exposed in this post. On the one side it stimulates the immune response, by producing AMP (LL-37). This is mainly produced by calcitriol (1,25D), on the other side high 25D Levels (calcidiol) acts immunosupressive and inhibits the innate response of the immune systems (and thus the immune response of the Flu shot is inhibited)

    Details can be found here:


  43. Dr. Eades — I can’t find anything specific about where I thought I read this, but is Vitamin A needed when you’re supplementing with D3?


    Excess vitamin A interferes with the proper functioning of vitamin D, so I wouldn’t take large supplemental doses of A. The amount you get in regular foods is not likely to be problematic.

  44. Re washing removes vitamin D on the surface of the skin, I think this is true but it’s hardly relevant unless you’re planning to lick it off. Vieth says in Effects of Vitamin D on Bone and
    Natural Selection of Skin Color: How Much Vitamin D Nutrition are We Talking About?

    ” Since vitamin D can be extracted from UV-exposed human sweat and skin secretions (Bicknell and Prescott, 1946), it is also reasonable to think that early humans obtained some of their vitamin D by mouth as well, by licking the skin.”

    An anthropologist gives alternative view of sunbathing and vitamin D.
    Mad dogs and ….

    Background on the centrality of meat in the diet of the European Paleolithic. P. 4 – hunting bands of the continental Arctic

    Thanks for the interesting links. I’m skeptical of the idea that vitamin D can be washed off, since the reaction making it occurs within the skin and not on the surface.

    The reason that vitamin D synthesis decreases with increased sun exposure is because increased sun exposure brings about tanning. And tanned or dark skin makes less vitamin D given the same amount of sun exposure, which is why dark skinned people living in northern climes are usually more vitamin D deficient than lighter skinned people living in the same area and getting the same sun exposure.

  45. I was able to … er… gently blackmail… my doc into writing me scrip for Tamiflu *and* Relenza by providing a copy of these two articles:
    “The Dilemma of Personal Tamiflu Stockpiling” ( and
    “Trying to get Tamiflu in case of a swine flu pandemic” ( It took a search of eight local pharmacies to find one that had any stock of Tamiflu (nearly $90 for a treatment course — single box, ten pills), but they didn’t have Relenza. (This was when the H1N1 flue was first becoming scary in Mexico.) I also bought face masks (I didn’t wear one on my last plane flight, came home with a HORRID cold… but not the flu {wink}).

    Now is the time to get educated (not by the mass media) and prepared; because either H1N1 will reassort (swap genes) with H5N1 (bird flu, which is terrifyingly lethal) and kill millions — or it won’t. Either H1N1 will stay (reasonably) mild coming into the next Northern flu season (this fall), or it won’t. No way to tell — but as with hurricanes, we *prepare* as if the hurricane is going to land directly on our house — and then cheer if it doesn’t!

    But I also take lots of Vitamin D: Preparation is preparation!

  46. @ Alex
    The Vitamin D newsletter scroll to the bottom of the page for Dr Cannell’s comments on Marshall.

    This Information about Trevor Marshall also raises concerns about integrity. If the computer software that underlies Marshall’s claims were available for independent scrutiny then maybe others would be able to replicate his findings.

    But until then the overwhelming evidence is that levels below 75nmol/l 30ng/mL actual physical harm is measurable in bones.

  47. Without wishing to confuse the very clear information provided in the illustration at the top of the page I’d like to point readers to this abstract
    Demonstration of UVB-induced synthesis of 1a,25-dihydroxyvitamin D3 (calcitriol) in human skin by microdialysis showing that calcitriol, vitamin d’s active metabolite, can be made by cells in the skin.

    In my opinion, given the amount of skin surface we have, it seems a pity that many people never allow our body’d largest peripheral organ to function in the way evolution intended.

  48. Robert Marshall is a fraudsterThere are serious life threatening consequences to following the Marshall Protocol that anyone with any common sense would do well to take note of some examples here there are more if you want.

    It’s Trevor Marshall. Thanks for the link.

  49. Doc-

    So if I start taking 5000 IU of D3 a day during the flu season, is it safe to stop taking it in the spring/summer? I am confused. Taking 1000-2000 IU of D3 can INCREASE my chances of getting the flu, but taking 5000 IU a day will DECREASE my chances? If I start taking 5000IU a day now, will I be even more susceptible to the flu if I stop taking the D3 in that amount? Basically, once I start on 5000 IU a day, I can’t stop?

    Please help.

    On summer days that I don’t go into the sun, I take a 5,000 IU vitamin D. On spring/fall/winter days I take one whether I go into the sun or not. I’m not sure about the info showing that you may be more susceptible if you stop taking. I don’t worry about it and just take as described above with one exception. If I am making a long flight, I pop a 50,000 IU cap before.

  50. I am 6 months pregnant and have a bad immune system i have gotten pneumonia almost every year since i was around 8 so when i saw site about vit d i started taking 1,000 more then i already was which was 400 units. since then i got a cold twice. i also have herpes type 2 and i had an outbreak i took the antiviral my dr gave me and it went away then i started taking 2,400 units a day of d3 and i also gave my husband who has a terrific immune system some vit d3 2,000iu in hopes he wouldnt bring home h1n1 to me and my son he then got an outbreak which we didnt even know he had it! then i got it on my mouth. i started taking the antivirals again as my dr prescribed and the blisters around my mouth just keep getting worse. i think the vit d3 is what made me have outbreaks and wont let it go away and also caused my husband to have his first. today is the first day i am not taking the vit d3. i am wondering if once the outbreak is gone should i start 5,000 units of d3 a day or not use it at all? i have not had my levels tested. i would appreciate any advice! thanks

  51. Absolutely wonderful website!

    Re-reading R. Vieth’s article on Vit D, “Vitamin D supplementation, 25-hydroxyvitamin D concentrations,
    and safety”, he describes the decreasing influence of UV when serum levels are elevated. I interpret this to mean that taking 6400 IU (my current level to attain 60 ng/ml) in the summer may be a waste of pills but not a hazard. In Seattle, even in summer, quality UV exposure is not always possible.

    Can I promote for their Vitamin D study?

  52. For some mysterious reason today I’ve received a googlemail dated 30 November 2009 06:07 alerting me to Venkat’s post 19. May 2009, 14:45

    @ Venkat
    Vitamin C reduces uric acid levels
    When using vitamin C remember the half life once absorbed is measure in minutes so buy low dose time release tablets and take regularly through the day.
    3 x 500mg time release, (ONE every 8 hrs) total 1500mg/daily, would be far more effective than 1500mg once daily

  53. Ted,

    Thanks a lot for your email. In my case, since I had introduced fish oil in my system and saw that the Uric Acid increase, I have discontinued fish oil. I have started on Carlson’s Cod Liver oil tablets (2 per day). I need to go and have the blood work done to see if UA is still a problem.

    But I am not sure why you got a reminder email. I have not done any changes.

    Thanks for the link.


  54. II became interested in Vitamin D last year. I had my blood tested in August 2009 and the results were a disappointing 30.1 ng/mL. So, I took 8000 IU/day for four months and had my blood tested again in January 2010, and my number was 53.4. Consequently, I reduced my D-3 intake to 6000 IU/day. Expecting to find my number leveling off, I had a test this week. To my surprise, the report was 25.3.
    How could it be that I supplemented with a high level of D-3 over this extended period, and yet reverted to a reading of only 25.3 ng/mL>

    1. Re “Consequently, I reduced my D-3 intake to 6000 IU/day. Expecting to find my number leveling off, I had a test this week. To my surprise, the report was 25.3.
      How could it be that I supplemented with a high level of D-3 over this extended period, and yet reverted to a reading of only 25.3 ng/mL”
      Could be test error. However levels can vary depending on your body’s requirements for anti inflammatory antioxidant reserves at 53ng/ml your body was only just building up a reserve. See Dr Davis’s Track your Plaque post called TOPPING UP YOUR VITAMIN D TANK and you’ll see he finds his patients take much longer than one would imagine to really fill the tank so he can reduce intake. I think maybe you were a bit premature though I am surprised at the size of the drop.

  55. Maybe this is a really basic question, but how do you know what your Vitamin D levels are? Can you test it yourself at home? I live in the Southwest where we get plenty of sunshine, but I’d be interested in testing if I was to start using megadoses of vitamin D, especially when treating illness.


  56. There are firms offering home 25(OH)D testing. and The vitamin d council bother offer this service. I think Dr Davis at Track Your Plaque does and in the USA there are also discountlab testing places that may offer 25(OH)D tests on special offer from time to time if your insurance won’t. I think most people will be surprised how low their 25(OH)D level is even if they spend time in the sunshine. Vitamin D is made of of the same precursor substances also used to create cholesterol so those following a cholesterol lowering diet or therapy may be less able to generate vitamin D3 when exposed to UVB.

    My view is that everyone should get tested and keep on testing every 6 months until they understand how much vitamin D from supplements their body requires. The spread of response to any daily intake is tremendous so unless you test you won’t know if your a high/low/medium responder.
    I keep my 25(OH)D at around 60ng/ml throughout the year with 5000iu/daily and plenty of FULL BODY sunshine. I live at latitude 52 and am now not obese but it took me far to long to realise (when I was obese) I needed more vitamin d than normal weight people.

  57. Some theories about increased need for D3;
    – conversion of D3 to active -OH forms requires magnesium, carbohydrate and gluten or phytates can deplete magnesium
    – low fat diet or poor fat absorption could reduce uptake, espcially from supplements which may not contain enough oil; try adding lecithin.
    – inflammation, cancer or chronic viral infection may cause vitamin D “sink” in immune cells, which take up vit D to use in interferon activity. Thus less of the total vit D pool would appear in the plasma.
    – vitamin D can also be broken down by sunlight, which prevents excess accumulating from UVB; perhaps some is being broken down by oxidative stress or by other catabolic processes.

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