Can we enlist vitamin D to fight flu pandemic?
Vitamin D and infectious diseases
Dr. John Cannell, one of most knowledgeable vitamin D experts and founder of Vitamin D Council, a nonprofit organization whose intent is to educate the public about the importance of this vitamin, first introduced the hypothesis that flu is merely a symptom of vitamin D deficiency in his paper Epidemic Influenza and Vitamin D, which was published in the journal Epidemiology and Infection.
According to Dr. Cannell, vitamin D helps produce antibacterial peptides, which fight bacteria and viruses.
Observations on the association between vitamin D and risk of dying from H1N1 virus
There are numerous observational studies suggesting that vitamin D deficiency increases risk of infectious diseases.
The CDC reported Sept 4, 2009 in its own journal Morbidity and Mortality Weekly Report (MMWR) that 36 children died from swine flu H1N1 virus between April and Aug. 2009.
In response, Dr. Cannell suggested in one of his vitamin D newsletters that the deaths were largely associated with vitamin D deficiency.
He pointed out that almost two-thirds of the dead children suffered epilepsy, cerebral palsy and other neurodevelopmental conditions like mental retardation, which have been well linked with vitamin D deficiency.
These kids often stayed indoors and did not get sufficient exposure to the sun and they took anticonvulsant drugs, together worsening their vitamin D status.
Blacks and Hispanics are more susceptible to swine flu H1n1 virus
Blacks and Hispanics are more susceptible to flu infections including swine flu, probably because they are more likely to be vitamin D deficient. Between 1916 and 1917, more blacks suffered H1N1 infection and because of this when the major 1918-1919 Hispanic flu pandemic stroke, blacks actually had lower illness rates because they had acquired immunity from their previous exposure to a similar virus.
Unpublished evidence and trial results suggest vitamin D helps fight flu
Dr. Cannell reported in his Sept 16, 2009 newsletter that two physicians, one in Wisconsin and the other in Georgia, observed that vitamin D supplementation can be the key to H1N1 flu prevention.
Norris Glick, M.D. of Central Wisconsin Center in Madison told Cannell in his email that 274 residents at his health care facility took vitamin D supplements and were monitored regularly for their plasma vitamin D levels; as a result, only two residents developed influenza-like illness and had positive tests for H1N1 during a period of observation. This compares to 103 of 800 staff members during the same period who were not required for the supplementation. This huge difference may be due likely to use of vitamin D supplements.
Dr. Ellie Campbell, who also responded to Cannell's vitamin D theory, told Dr. Cannell in an email of a similar observation. She said she told her patients to take 2,000 to 5,000 IU of vitamin D regularly and monitored their serum levels to make sure her patients had sufficient Vitamin D in their blood. Campbell shared office with another physician. Her office mate did not do the same thing to his patients. When the H1N1 hit George, none of her patients came to see her for H1N1 virus infection; the other physician was seeing one to 10 cases per week of influenza-like illness.
Most recently, a Japanese trial has demonstrated that taking high doses of vitamin D3 supplements may be as effective as flu vaccine at reducing the risk of flu during the winter, particularly in school children.
The trial results showed that among school children taking 1200 IU per day of vitamin D3 supplements, 10.8 percent of children had influenza, as compared to 18.6 percent of controls. This means that vitamin D3 reduced the risk of the flu by 48 percent, which could be comparable to the efficacy of flu vaccine.
The randomized, double-blind, placebo-controlled trial was conducted by Mitsuyoshi Urashima, MD, PhD, from Jikei University School of Medicine, Minato-ku, in Tokyo, Japan and published online in the March 10, 2010 issue of the American Journal of Clinical Nutrition.
For the trial, Urashima and colleagues compared 167 children taking 1200 IU per day of vitamin D3 supplements; 167 children who did not take the supplement to evaluate the difference in the incidence of influenza A between Dec 2008 and March 2009.
The vitamin D theory
A new study led by researchers at the University of Copenhagen has confirmed that vitamin D plays an important role in activating immune defenses against infectious diseases such as the flu.
Garsten Geisler and colleagues published their study in Nature Immunology, detailing how vitamin D works to prevent infectious disease.
The whole process goes like this: the naive T cell first recognizes foreign invaders like flu viruses with T cell receptors. Once an invader is spotted, the T cell activates the vitamin D receptor gene and starts production of vitamin D receptor protein, which binds vitamin D in the T cell and becomes activated. Then, the activated vitamin D receptor gets into the cell nucleus and activates the gene for PLC-gamma1 to produce PLC-gama1 protein, thereby readying the T cells to fight the invaders.
Dr. John Cannell's recommendations
1) Take enough vitamin D 3 to maintain this vitamin above 50 ng/mL or 125 nmol/L. This requires taking at least 5,000 IU per day for adults; some adults may need more. Children should take 1,000 IU per every 25 pounds of body weight. After three months, test your 25(OH)D level. Adjust intake of vitamin D accordingly so that the serum vitamin D level falls between 50 to 70 ng/mL. Low levels of this vitamin leas to high risk of a 1918-like influenza virus.
2) Dr. Cannell believes that vitamin D did not play a controlling role in 1918. The lethality of the 1918 virus overwhelmed innate immunity associated with vitamin D. Because of this, 50,000 IU capsules of vitamin D3 should be stored at home and when a flu pandemic virus strikes, take 2,000 IU per kg pf body weight per day for a week.
3) Get the H1N1 flu shot as soon as possible, particularly if the virus shows evidence of high lethality. The vaccine may increase risk of Guillain-Barré Syndrome, but the risk is small. The highest risk was found in non-vaccinated people who were infected with the virus.
4) Stock up on Tamiflu.
(This article may contain content from Dr. Cannell's articles)
By David Liu and editing by Rachel Stockton (Photo credit: wikipedia)