The Sunshine Vitamin?
With vaccine production months away how can you avoid the flu? In February 2009 research suggested that sunshine is more than just a home remedy. The study found that people with low levels of vitamin D — also known as the “sunshine vitamin” — were more likely to catch cold and flu than folks with adequate amounts.
The effect of the vitamin was strongest in people with asthma and other lung diseases who are predisposed to respiratory infections. We wrote about this on June 25 in this blog but it is worth repeating…it seems that in an effort to discover new ways to fight H1N1, the Public Health Agency of Canada yesterday announced it intends to test the blood of people contracting the ailment to check their vitamin D levels.
The agency is taking the unconventional action to try to find out whether those with mild cases of the flu have more of the Vitamin D circulating in their bodies than those who develop severe or even deadly reactions to the H1N1 virus.
If researchers determine that the vitamin protects against H1N1, it will give health authorities another line of attack against the pandemic, besides the usual solutions such as large-scale vaccinations and hand-washing campaigns.
Study Reveals Vitamin D Makes A Big Difference
The February 2009 study determined that people with the worst vitamin D deficiency were 36 percent more likely to suffer respiratory infections than those with sufficient levels, according to the research in this week’s Archives of Internal Medicine. Among asthmatics, those who were vitamin D deficient were five times more likely to get sick than their counterparts with healthy levels. And the risk of respiratory infection was twice as high among vitamin D-deficient patients with chronic obstructive pulmonary disease (COPD) than in lung patients with normal levels of the vitamin.
Having 30 nanograms of vitamin D per milliliter of blood is considered optimal. More than half of the people in the study had vitamin D levels below that threshold. The most recent recommendations from the Institute of Medicine (IOM), which are 12 years old, say that Americans should get 200-600 International Units of vitamin D a day. But those recommendations were set based on the vitamin’s contribution to bone health, not immunity and overall wellbeing. Proponents of more vitamin D intake, such as Michael Holick, say 1,000-2,000 IUs might be needed. An IOM update to the recommendations is expected in May 2010.
“It’s clear that the American population needs more vitamin D overall for its effects on bone health and the growing literature on non-skeletal benefits for general health,” says Ginde, who expects participants in an upcoming vitamin D trial will get the amped up levels of 1,000-2,000 IUs that advocates are pushing for. “We’re not recommending that everyone go out and take that, but that’s the magnitude of change we’re talking about.”
Sources for Vitamin D
How does one get more Vitamin D? Very few foods in nature contain vitamin D. The flesh of fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources. Fortified foods provide most of the vitamin D in the American diet. For example, almost all of the U.S. milk supply is fortified with 100 IU/cup of vitamin D (25% of the Daily Value or 50% of the AI level for ages 14-50 years). In the 1930s, a milk fortification program was implemented in the United States to combat rickets, then a major public health problem. This program virtually eliminated the disorder at that time. Other dairy products made from milk, such as cheese and ice cream, are generally not fortified.
Exposing yourself to sunlight is the most important source of vitamin D because sunlight is far more likely to provide you with your vitamin D requirement than food is.UV rays from the sun trigger vitamin D production in your skin. Season, geographic latitude, time of day, cloud cover, smog, and sunscreen affect UV ray exposure and vitamin D synthesis. For example, sunlight exposure from November through February in Boston is insufficient to produce significant vitamin D synthesis in the skin.
Sunscreens – Great To Avoid Skin Cancer, Not So Good For Vitamin D Absorption
Sunscreens with a sun protection factor (SPF) of 8 or greater will block UV rays that produce vitamin D. An initial exposure to sunlight of 10 to15 minutes allows you adequate time for Vitamin D synthesis and should be followed by application of a sunscreen with an SPF of at least 15 to protect the skin. Ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen is usually sufficient to provide adequate vitamin