Vitamin D for the FLU

Vitamin D for Influenza

            To Your Health
            October, 2010 (Vol. 04, Issue 10)

      Vitamin D for Influenza
      By Dr. James Meschino
      Another flu season is here; what's your strategy this year? In 2009, many
      chose the vaccine route, particularly with the "swine flu" (H1N1) making
      front-page news on a near-daily basis. Whether you choose to get
      vaccinated or not, it's important to be aware of a simple, natural way you
      can help reduce your risk.
      Every year the medical profession and government authorities encourage
      citizens in many developed countries to get immunized against the current
      form of influenza virus. This year is no different, particularly with the
      "dreaded" swine flu still on everyone's minds. While the decision to get
      vaccinated is an individual one with both pros and cons, consider that a
      natural approach, namely supplementation with specific nutrients such as
      vitamin D, can boost immune function and may play an important role in the
      prevention of respiratory tract infections.
      Why Vitamin D?
      In recent years, studies have shown that vitamin D is an important
      modulator of immune function. Some authorities suggest it has the
      potential to reduce the risk of life-threatening influenzas based on the
      initial observation that influenza normally strikes in countries during
      the colder (winter) months, when vitamin D production in the skin
      declines. This happens because the most generally available source of
      vitamin D is sunlight. Reduction in skin production of vitamin D due to
      reduced or no exposure to daily sunlight is accompanied by a decline in
      blood levels of vitamin D.
       Some vitamin D experts suggest adults should supplement with 2,000 IU
      vitamin D per day (especially during the winter) as a means to maintain
      more optimal vitamin D status in general, strengthen immune function and
      help reduce the risk of influenza and its invasion into the lung cavity.
      Other experts suggest dark-skinned individuals should supplement with
      5,000 IU of vitamin D per day during the winter months to help ensure they
      attain blood vitamin D levels (25-hydroxycholecalciferol) at or above 50
      ng/ml. (Melanin, the pigment that makes the skin darker, acts as a
      sunscreen, reducing vitamin D production in the skin upon exposure to
      solar radiation.)
      How Vitamin D Affects Immunity
      Most immune cells contain vitamin D receptors which allow vitamin D to
      enter the cells and exerts its effects on immune cell behavior. In this
      capacity, vitamin D has been shown to dramatically stimulate the
      expression of potent antimicrobial peptides. These peptides exist in white
      blood cells such as neutrophils, monocytes and natural killer cells, and
      the epithelial cells that line the respiratory tract, where they play a
      significant role in protecting the lung from infection.
      Vitamin D influences both innate and adaptive immunity. The cells of the
      innate system recognize and respond to pathogens (infectious agents or
      germs) in a generic way, and the adaptive immune cells have the ability to
      recognize and remember specific pathogens. They, in turn, generate
      immunity by mounting stronger attacks each time the same pathogen is
      encountered. In simpler terms, vitamin D appears to make immune cells
      better able to fulfill their primary function - defense.
      Adaptive immunity involves lymphocytes (a specific type of white blood
      cell) that are able to express a vast number of specific antigen receptors
      on their cell surface. Should the pathogen be reintroduced at a later
      point in time, these receptors are activated and the lymphocytes launch an
      assault against the pathogen. In adaptive immunity, all of the offspring
      of the activated cells inherit genes, encoding the same receptor
      specificity. These cells include the memory B cells and memory T cells
      that are the keys to long-lived specific immunity.
      Vitamin D receptors are expressed in monocytes and in activated
      macrophages, dendritic cells, natural killer cells, and T and B cells.
      Activation of these receptors by vitamin D has been shown to increase the
      activity of natural killer cells and enhance the phagocytic activity of
      macrophages. (Phagocytes are white blood cells that protect the body by,
      for lack of a better word, "eating" harmful foreign particles, bacteria,
      etc.) Active vitamin D hormone also increases the production of
      cathelicidin, an antimicrobial peptide that is produced in macrophages.
      The release of cathelicidin is triggered by the presence of bacteria,
      viruses and fungi.
      All of these influences enable the immune system to work in a highly
      efficient manner, reducing risk of infection and reducing severity of
      infections should they strike. These immune pathways are also important in
      preventing cancer. In fact, higher blood levels of vitamin D are
      associated with reduced risk of breast, prostate, colon and other cancers.
      Several intervention studies have shown that vitamin D supplementation is
      associated with a reduction in cancer incidence of approximately 50
      percent and that supplementation of 2,000 IU per day slows the progression
      of localized prostate cancer in a high percentage of male subjects.
      Vitamin D Deficiency
      While optimum vitamin D status seems to protect against influenza and
      other conditions, vitamin D deficiency is associated with increased risk
      of infections, such as influenza and tuberculosis. In one study,
      volunteers inoculated with live attenuated influenza virus were more
      likely to develop fever and serological evidence of an immune response in
      the winter. Vitamin D deficiency also has been reported to predispose
      children to respiratory infections. Ultraviolet radiation (either from
      artificial sources or from sunlight) has been shown to reduce the
      incidence of viral respiratory infections. The same holds true for cod
      liver oil supplementation, which is a rich source of vitamin D.
      Think Prevention
       I believe it is important for health practitioners to establish patients'
      baseline vitamin D blood levels. Evidence strongly suggests that a level
      above 85 nmol/L is highly protective against osteoporosis, cancer,
      multiple sclerosis and various infectious processes. Vitamin D toxicity is
      a concern only when blood levels of vitamin D rise above 200 nmol/L.
      Recent research indicates that supplementation with 1,400 IU of vitamin D
      per day appears to be sufficient to raise vitamin D level to the 85 nmol/L
      level in most patients. And at the first sign of flu-like symptoms, one
      expert - based on personal experience and that of family members -
      suggests supplementing with 2,000 IU of vitamin D per kilogram of body
      weight for three consecutive days.
      Anyone who's suffered through the flu knows that it's not only potentially
      dangerous; it can be downright miserable. Ask your doctor to assess your
      current vitamin D status and discuss the value of vitamin D
      supplementation, particularly during the flu season. Whatever your
      strategy, it won't eliminate your risk altogether, but why not do
      everything you can do naturally to protect yourself and your loved ones?

      Boosting Immune Function: From A to Z
       Vitamin D isn't the only ally in the battle against influenza and other
      immune-related conditions. Supplementation with vitamin C, vitamin E,
      beta-carotene, selenium and zinc appears to boost immune function (even in
      elderly patients) and, in some studies, has reduced the incidence of
      respiratory infections. And studies have shown that concurrent
      supplementation with certain antioxidants can even enhance the protective
      effects of the influenza vaccine. As such, I recommend a high-potency
      multivitamin/mineral to virtually all adult patients that contains 1,000
      mg of vitamin C, 400 IU of vitamin E (succinate), 100 mcg of selenium,
      10,000 IU beta-carotene, 15 mg of zinc and a B-50 complex, among the list
      of all vitamins and minerals from "A to Z." Such a multivitamin/mineral
      should also include vitamin D, of course, which has received attention in
      recent studies for its powerful affect on immune function.

      James Meschino, DC, MS, practices in Toronto, Ontario, Canada and is the
      author of four nutrition books, including The Meschino Optimal Living
      Program and Break the Weight Loss Barrier.

      Page printed from:
      http://www.toyourhealth.com/mpacms/tyh/article.php?id=1346&no_paginate=true&no_b=true