In the past few months, we have sent out several posts on vitamin D and other nutrients and their influence on immune system function and incidence of colds and flu. Today, we present that information in a summarized, easy-to-access format.

Your Immune Cells Rely on Vitamin D


  • Vitamin D Activates the T-cells for Immune Response
  • How Does Your Immune System Work?
  • The Innate vs Adaptive Immune Response
  • The Role of T Cells in Destroying Viruses
  • Is your immune system strong enough to help you stay healthy?

Vitamin D: An Orchestrator of Immune Responses

Actions of vitamin D:

  • With immune and epithelial cells (such as those in the lungs and gastrointestinal tract)
  • With white blood cells and pathogen destruction
  • Immune modulating effects within the microbiota

Vitamin D and Immunity: Tying it All Together

More Complex Vitamin D Dependent Functions in the Adaptive Immune Response

  • Vitamin D is needed to activate T cells, turning naïve T cells into primed T cells that are better able to respond to a pathogen
  • Vitamin D influences T cell differentiation to induce lower levels of inflammatory cytokines and higher levels of anti-inflammatory cytokines
  • Vitamin D regulates the maturation of the dendritic cells, another type of white blood cells, to then modulate helper T cell (Th) function
  • T cells respond directly to active vitamin D by developing regulatory T cells

A Healthy Immune Response Relies on Your Nutrient Status

“There is a close relationship between nutritional status and immune function. Hence, immunocompetence can be regarded as a measure of adequate nutrition.” This post reviews how the immune system relies on the following nutrients:

  • Vitamin C
  • Vitamin D
  • Zinc

Immune Response Affected by Nutrient Status and Other Factors

The following are additional factors to consider for maintaining healthy immune function:

  • Age
  • Environmental Temperature
  • Air Pollution
  • What’s the Bottom Line?
  • What’s the Main Action to Take?

Cold and Flu Season is Approaching (Part 1)

  • Vitamin D Levels and Flu Activity by Season
  • Is there an association between vitamin D and the incidence of cold and flu?

Cold and Flu Season is Approaching (Part 2)

  • How could vitamin D help prevent the flu?
  • Dr. Carlos Camargo explains the connection (Video)
  • What does the research say about vitamin D and the flu?

Cold and Flu Season is Approaching (Part 3)

More examples of research supporting the role of vitamin D in the prevention and outcome of respiratory infections.

Cold and Flu Season is Approaching (Part 4)

What else, besides vitamin D, might help decrease the risk of getting a cold or flu, or the time and severity of symptoms if you do get sick?

  • Could Omega-3s Make a Difference for Colds and Flu?
  • What about Zinc?
  • Is the flu vaccine the best way to protect against the flu?

Could Your Immune System Benefit from Vitamin D?

Make sure you know your vitamin D level, and take steps to keep it within a target of 40-60 ng/ml or 100-150 nmol/L! Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Test Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created the Personal Health Nutrient Decision System called

For each specific supplement, you can track what days you take it, how much, and many other details.  This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels.  Check it out today!