Swine Flu and Vitamin D3

I was aware that during the SARS mini-epidemic, severely ill patients were in many cases stabilized and given the chance to recover by administration of prednisone, and to the extent that this represented a truly effective treatment (admittedly undecided at this point, and thank God there were not enough cases to establish it definitively), it meant that a major contributor to the pathology of SARS was inflammation of the lungs, consistent with an over-reaction by the immune system, out of proportion to what is necessary to clear the virus.

This also seemed similar to the pathology of the 1918 influenza pandemic, and some of the anecdotal reports of deaths from the current H1N1 strain, where progression from minor symptoms to death can occur within 24 hours, seemingly not long enough to incur massive viral lysis of lung cells. Vitamin D is known to have some of the same anti-inflammatory properties, and deficiency is linked to childhood asthma (2), suggesting that it may play a role in the pathology of influenza also.

Influenza is a seasonal disease, most prevalent during winter, which is often explained as being because the UV light, heat, or humidity of summer inactivates viruses more quickly.

It may instead be because winter is a time when most people in northern countries are deficient in vitamin D. When researchers looked at serum vitamin D levels in patients in the United states, they found widespread deficiency (3), and concluded that current recommendations
for supplementation are inadequate to address the deficiency.

When the same group of researchers studied the incidence of upper respiratory tract infections, there was an inverse relationship between vitamin D deficiency and those infections (4). These papers were covered in the popular press (5) also.

The relationship between deficiency in solar radiation and flu was was first suggested by R. Edgar Hope-Simpson in 1981, and a recent paper (6) identifies vitamin D as the factor induced by solar radiation. This was accompanied by a narrative from the physician who made the initial observations and involved scientists to develop the paper (7), where the strongest case is made, both scientifically, and by linking known facts, that vitamin D deficiency is the key factor that predisposes to influenza.

That last link makes the case most comprehensively, and now that I have discovered it, I realize it was there before I came to the same realization. The author states that he and his colleagues have experimented on themselves and their families and found the results very persuasive, although tainted by bias.

I can share the same observation: For many years I have suffered from non-stop colds, flu, and secondary infections and coughs long after shaking the initial bug. I live in [edited out], New York, and sunshine can be limiting here, especially in winter. Last spring was particularly rainy and my symptoms lasted into July when I started vitamin D3 at 4,000 units per day. The results were very quick and last winter was my first without upper respiratory infection. My children have had the same benefit, and when sick recover very quickly if given vitamin D.

Also useful is the well documented Wikipedia entry on Vitamin D (8), especially regarding dosing and establishing maximum doses. Consensus opinion is that the maximum doses should be set at 2,000 units per day rather with a maximum of 10,000 units per day for two or three days as "shock therapy". In any case, we recommend that the family physician should be consulted if in doubt.

The information about fatalities in the H1N1 outbreak is lacking, but one thing that comes up again and again is that there was some underlying immune problem, usually auto-immunity, allergy, or other over-reaction of the immune system, as opposed to AIDS, for example. This spring has been cool and rainy in much of the world, implying conditions unfavorable to people receiving vitamin D from sunlight.

I would like to suggest that all the facts point to a key role of vitamin D in making the outbreak of H1N1 the very mild infection seen in most patients, and not the severe immune over-reaction seen in the small minority that are killed by it.