Influenza, Flu Shots, and Vitamin D

Dear Cynthia: I don't know and I don't know. However, I am beginning to believe that vitamin D is at least as protective as flu shots, although such a head to head comparison has never been done. The reason I say that is twofold:

1. Several randomized controlled trials of vitamin D have suggested that the right dose of D may be as protective as most studies of the effectiveness of flu vaccines.
2. Mass vaccination of our elderly has failed to reduce the rate of influenza hospitalization or death rate among the elderly.

However, I suspect that as flu vaccinations rates in the elderly went up in the last 30 years, acquired immune deficiency syndrome due to vitamin D deficiency also went up and the two canceled each other out. Remember, of all age groups, the elderly are most likely to avoid the sun.

A very well written and exhaustive epidemiological study of vitamin D and the flu published last week from Norway, suggests vitamin D may be the major controlling factor in influenza epidemics and even most pandemics. This lovely paper was written by Dr. Asta Juzeniene, with Dr. Johan Moan the senior author, both of the Oslo University Hospital. I am not just saying I liked it because they credited me with the discovery; it is a great paper.

Juzeniene A, Ma LW, Kwitniewski M, Polev GA, Lagunova Z, Dahlback A, Moan J. The seasonality of pandemic and non-pandemic influenzas: the roles of solar radiation and vitamin D. Int J Infect Dis. 2010 Oct 28.

They used data from all over the world, from the last 110 years, to show that influenza death rates go up as vitamin D producing UV light goes down. Furthermore the differences were staggering, with influenza death rates 20 to 600 times higher during months when vitamin D cannot be made in the skin. While some of this is a direct "antibiotic" effect of vitamin D, some of it is likely due to vitamin D causing innate "herd immunity." The total vitamin D "effect size" hinted at in this Norwegian paper is staggering.

The vitamin D "herd immunity" effect means that if you're the only one in your family on vitamin D, then your risk of getting the flu is lower but you still have a reasonable chance of getting the virus. If everyone in your family takes vitamin D, but no one else at your child's school does, then your risk of being exposed and getting sick is even lower. If everyone in your town (herd) takes it then your risk is even lower, if everyone in the country, even lower, etc. This is due to the "herd immunity" effect that is well established for influenza antibodies and I hypothesize is true for vitamin D as well.

Last year I spent a lot of time reading letters saying, "I got the H1N1 in spite of taking 5,000 IU per day, you quack." First, I estimate that only about 1/1,000 of people who think they have influenza A actually have influenza A. Most have other viruses. Even when people were sick enough with influenza symptoms to go to their doctor, and the doctor concerned enough to start anti-viral drugs and also send a specimen to the CDC, only about 2% of those specimens showed influenza A. Even people with classic flu-like symptoms, fever, cough, body aches and prostration (lying flat on your back) often do not have detectable influenza A infection.

Secondly, like the flu vaccine, vitamin D is not 100% protective, even against influenza A. It only reduces your risk of getting sick. Believe me, even if your vitamin D level was perfect (whatever that is) and you had the flu shot, it would be easy to spray enough virulent influenza virus down your lungs to kill you quick.

Because of both the antibiotic and the "herd immunity" effect of vitamin D, I recommend you get your herd on vitamin D this flu season. The correct dose is 5,000 IU/day for adults and approximately 1000 IU/25 pounds/day for children. I also believe that the vitamin D should have the cofactorsthat most Americans are deficient in anyway, magnesium, vitamin K2, zinc, and boron.

I continue to get a flu shot as does my wife and children. My thinking is simple: I believe the scientists, and, a few more antibodies can't hurt, although I am aware of Russian studies that show systemic immune response to flu vaccinations are highly seasonal and antibody formation is directly proportional to systemic immune response. That is, high vitamin D levels may decrease or prevent antibody formation from a flu shot. It would be an easy scientific study to do, just find some banked blood drawn on the day of immunization, and then see which subjects formed the most antibodies down the line, the ones with high vitamin D or the ones with low levels.

I have read quite a few papers on flu vaccines. Unlike some of you, I do not think these scientists are crooks, all bought off by the vaccine industry, anymore than I have been bought off by the vitamin D industry. I'll continue to get my flu shot and I'll continue to take my vitamin D.

However, as time goes by, and more and more people obtain summertime vitamin D levels year around, I suspect — if the findings in Dr. Asta Juzeniene paper are confirmed — the main reasons to get the flu shot every year will become more habit than knowledge, more social than medical, more financial than scientific.

John Jacob Cannell MD Executive Director