With flu season just around the corner and as the numerous strains of the influenza virus continue to pose a deadly danger to public health, this seems like a good time to share the work of several pioneering experts. They maintain that sufficient levels of vitamin D have the capacity to supercharge the immune system and lower the risk of infection. Their findings also underscore the inadequacy of current “recommended” daily doses of 400-800 IU. To get the full immune-boosting benefit, about ten times that amount may be required to achieve optimal blood levels of vitamin D in its active form.

Vitamin D provides unrivalled support for the innate immune system, the foundation of your body’s defense that is hard-wired to respond instantly to microbial invasion. The innate immune system is the branch of the immune system that responds immediately to dangerous microbes. As soon as an invasion is detected the innate immune system releases virus killing compounds called antimicrobial pepticles (AMP). The tissues that line our air passages are especially rich in AMP producing cells where they provide a front line defense against influenza.

Only in the past few years have scientists discovered that these cells require vitamin D to function effectively. Vitamin D acts by modulating gene expression, activating the genes that govern AMP production. Respiratory tract cells convert vitamin D into its active form reflecting the intimate relationship between vitamin D and host defenses.

Vitamin D also suppresses inflammatory cytokines. Cytokines (Greek: cyto-, cell; and – kinos, movement) are several different types of substances that are produced by cells within the immune system. These substances relay signals between the immune cells.

Sometimes referred to as polypeptide regulators, there are two groups of inflammatory cytokines, each with their own particular characteristics and functions. The form we are referring to is known as the pro-inflammatory polypeptide regulators. These types of cytokines are created primarily by immune cells that are engaged in the process of amplifying inflammatory reactions as a means of dealing with some sort of health threat to the body, for example influenza.

Cytokines are partly responsible for the pain, fever, and congestion that come with the influenza infection; full-blown cytokine storms are to blame in some fatal cases of influenza. Vitamin D not only enhances our ability to produce AMP molecules, it also simultaneously dampens the acute inflammation that causes most of our symptomatic misery during a bout of influenza.

While the underlying mechanisms behind vitamin D’s immune-supporting action have only recently come to light, scientists have long suspected that vitamin D protects against influenza and other respiratory infection. Influenza is highly seasonal, occurring during the month of fewer daylight hours and greater cloud cover. Since vitamin D requires sunlight for activation, researchers suspected a connection.

An early study demonstrated that mice with low vitamin D levels were at higher risk for experimental swine flu. Numerous studies have shown that infants, children, and adults are at increased risk for influenza and other serious lower respiratory infections when their vitamin D levels decline.

One 2009 study found that the risk was 36% greater for healthy people with low vitamin D levels. The current recommended daily amount of 400 – 800 IU was established more than 30 years ago and it was aimed at establishing the minimum required to avoid osteoporosis. These amounts are far too low to provide vitamin D at immune-supporting levels. The body can produce blood levels of activated vitamin D in far greater amounts than we normally ingest. In order to generate any significant benefit, researchers had to give 6,000 IU of vitamin D to healthy adults in order to maximize production of the active form. This implies that everyone has a chronic vitamin D deficiency, at least in the winter, when the influenza danger is the worst.

Optimal Flu Prevention

• Epidemic seasonal influenza strikes every year while the recent H1N1 “Swine” flu has spread with alarming speed.
• Vitamin D has powerful immune-boosting properties, up regulating genes for vital antimicrobial pepticles that can kill influenza viruses as soon as they land in our airways.
• To optimize vitamin D’s immune-enhancing effects, most individuals must take far higher doses than are usually recommended.
• Practicing clinicians have achieved efficacy with daily vitamin D supplements of 5,000 IU or higher – virtually eliminating influenza infections even among vulnerable populations.
• Start vitamin D supplementation today. Get your levels checked twice a year to be sure you are reaching optimal levels to support your immune system.
• Use wet wipes when you go shopping to make sure the cart handle is clean.
• Carry a natural hand sanitizer with you when you are away from home.
• Wash your hands frequently.
• If you sneeze, sneeze into your arm not your hand.
• Get lots of sleep and drink lots of pure water.
• If you don’t feel well and are running a fever of 99 or above, stay home.