3 Immune System Strengthening Tips (no FLU for me!)

Last Updated:


By: Alirio Zavarce

Strong Immune System

Your body makes its own natural antibiotics called Antimicrobial Peptides or AMPs. These AMPs are key natural defenses that your body produces to defend against bacteria and the flu virus.

In this post, you’ll learn how to naturally promote the production of AMPs as well as what affects their decline in Vitamin D-dependent and a Vitamin D-independent processes.

Are you ready? Let’s get started.

This page contains affiliate links, meaning that we receive a commission if you decide to make a purchase through our links; however, this is at no additional cost to you. Thank you in advance if you use our links!

Increase Your Vitamin D

Sunlight for Vitamin D
Exposure to Sunlight Increases Your Production of Vitamin D

Vitamin D is very important to activate your defenses against the flu. Let’s take a look at how that works and how to prevent those levels from decreasing.

In a randomized placebo-controlled trial in Japan, they found that subjects supplemented with vitamin D had 42% reduction in flu cases; however, some of the subjects who received vitamin D supplementation got the flu. Why? To answer this, you need to understand how vitamin D works in your immune system.

Vitamin D doesn’t interact with the flu directly. Instead, Vitamin D is part of a set of biological steps, or pathway, that your immune system need for proper operation, and understanding this process is very important.

Your body needs Vitamin D to produce its own “natural antibiotics,” a set of chemicals called Antimicrobial Peptides (AMPs). These AMPs are an important component in both your body’s antimicrobial response and defenses against the flu. These “natural antibiotics” are molecules that are not toxic to humans; don’t kill your microbiome; and are so diverse that there’s no way for microbes to develop resistance to them.

Vitamin D induces the production of a class of AMPs called Human Neutrophil Defensins that inhibit the infectivity of the influenza A virus. In other words, a lack of vitamin D in your body negatively affects the production of AMPs leaving your immune system weak and more susceptible to a bacterial or flu virus infection. This is one of the reasons why Vitamin D is paramount to produce natural defenses against microbes and flu!

[amazon box=”B07FF9535Z” template=”horizontal” button_detail=”https://amzn.to/3HXwy7D” button_detail_target=”_blank”]

Remember that your body’s antimicrobial and anti-flu defenses are very similar because they both rely on AMPs.

When the body needs Vitamin D, the body converts it from its inactive form, 25D, into its active form, 1,25D, which in turn binds to the Vitamin D Receptor (VDR) on the membrane of your cells to stimulate the production of anti-microbial peptides (AMPs).

Vitamin D Assists in the Production of AMPs that Fight the Flu Virus
Vitamin D Assists in the Production of AMPs that Fight the Flu Virus

25D is the inactive, storage form of Vitamin D that circulates in our blood stream. Those Vitamin D tests that your doctor prescribes measure this version of vitamin D, called 25D. When the immune system needs to activate VDRs, the immune system converts 25D into its active form 1,25D.

The CYP3A4 is an enzyme responsible for degrading the active form of vitamin D into inactive forms (1,23,25D and 1,24,25D) because too much of the active form can be toxic; however, there are situations in which CYP3A4 can overdo its job because the body produces too much of it.

Now, what causes a rise of CYP3A4 levels that results in a reduction of your Vitamin D levels?

Xenobiotics and mycotoxins. Let’s take a look at each.

Xenobiotic comes from the words xenos, meaning foreign, and bios, meaning life. Xenobiotics are those chemicals not normally produced or expected to be present in an organism, but they are still found in it. In other words, xenobiotics are chemical compounds found in a living organism that don’t belong to that organism in the sense that it does not normally produce the compound or consume it as part of its diet.

The Meaning of Xenobiotics
The Meaning of Xenobiotics

For instance, most drugs are part of this category since people don’t produce them naturally, or consume them under normal circumstances. Xenobiotics can also be defined as substances that are present in higher-than-normal concentrations, or ones that are entirely artificial and did not exist before they were produced synthetically by humans. A compound that is normal to one organism may be a xenobiotic to another.

Xenobiotics in your body induce the production of CYP3A4 as part of a detoxification process, so xenobiotics can be cleared from your body; however, these higher levels of CYP3A4 also affect your active Vitamin D levels by converting Vitamin D into its inactive form resulting in an increased requirement for Vitamin D from sunshine or diet.

A Rise in Xenobiotics Causes a Rise in CYP3A4 and a Reduction of Vitamin D Levels
A Rise in Xenobiotics Causes a Rise in CYP3A4 and a Reduction of Vitamin D Levels

Needless to say, reducing your intake or exposure to foreign chemicals reduces the need to increase your levels of xenobiotics that result in the inactivation of the active form of Vitamin D levels.

Another way to increase the effectiveness of your Vitamin D levels is by increasing the number of Vitamin D Receptors, or VDRs. Lactobacteria in probiotics increases VDR levels.

[amazon box=”B000MMO782″ template=”horizontal” button_detail=”https://amzn.to/3LIceth” button_detail_target=”_blank”]

On the contrary, mycotoxins from black mold (Aspergillus fumigatus) decrease VDR levels by reducing the genetic expression of Vitamin D Receptors.

Mycotoxins are toxic substances produced by fungi, usually as secondary metabolic products. Fungi generate some toxins in the process of building the amino acids that they use to digest the materials they eat.

Lactobacteria Increase VDRs - Mycotoxins Decrease VDRs
Lactobacteria Increase VDRs – Mycotoxins Decrease VDRs

So, if you live in a place with black mold and are breathing it, your VDR levels are probably low, which affect the anti-microbial peptide production pathway.

The key to increase your AMP levels is to increase your lactobacteria and lowering your exposure to mycotoxins.

Take Curcumin!

Curcumin Strengthens Your Immune Response
Curcumin Strengthens Your Immune Response

There is another way to increase your AMP levels without depending on the Vitamin D Receptors, and that is with the consumption of CURCUMIN!

Curcumin is a phytonutrient found in turmeric that induces the production of cathelicidin, an AMP that does not depend of Vitamin D Receptors.

The importance of curcumin here is that curcumin is known to inhibit the infectivity of enveloped viruses such as the influenza A virus.

Think of curcumin as a backup mechanism for the VDR-dependent pathway to produce Anti-Microbial Peptides!

In other words, curcumin promotes the production of AMPs outside of the vitamin-D dependent mechanisms.

[amazon box=”B00DSFG6ES” template=”horizontal” button_detail=”https://amzn.to/3h0RLBU” button_detail_target=”_blank”]

Increase Protein & Reduce Sugar

Sources of Proteins
Sources of Protein

Bear with me as I’ll build the case since many components are related.

Neutrophils are immune system cells of the type of white blood cells (leukocytes). Neutrophils are also called granulocytes because they contain granules.

Neutrophil granules contain critical enzymes for bacterial and fungal killing. Neutrophils also release other chemicals outside the cells to kill bacteria and recruit additional immune system cells to the region of infection or inflammation.

Neutrophils have two main functions:

  1. Secretion of anti-microbial peptides (AMPs) such as Human Neutrophil Defensins
  2. Phagocytosis (engulfing and destroying pathogens such as bacteria in the lungs)

Neutrophils were thought to have an antibacterial role only, but recently it was discovered that neutrophils also are part of the innate anti-viral pathway on epithelial surfaces on the skin even before interferon kicks in. Remember that interferon is responsible for the containment and blocking of viral replication and starts within hours after viral infection. Neutrophils are activated immediately.

Neutrophils are Antibacterial & Antiviral
Neutrophils, a type of white blood cell, are Antibacterial & Antiviral

What can prevent Neutrophils from performing correctly? Low levels of glutathione and high levels of sugar.

Cystic fibrosis patients suffer from pulmonary exacerbations in which patients present episodes of acute worsening of symptoms caused by neutrophils chronically low on intracellular glutathione. These low-glutathione neutrophils behave differently than normal neutrophils. Normal neutrophils go to the lungs and attack bacteria by engulfing and killing it (phagocytosis) whereas cystic fibrosis neutrophils induce inflammation and lung tissue damage by releasing harming chemicals. Normalizing glutathione levels via supplementation prevents those pulmonary exacerbations!

How to Increase Glutathione Levels?

Remember that glutathione is the body’s major antioxidant produced by your liver.

Protein is made of amino acids and when you eat protein, your stomach acid breaks down that protein into individual amino acids. Now, in order to stimulate the production of glutathione in your liver, your body needs three amino acids:

  • Glutamate
  • Cysteine
  • Glycine

Unless you’re starving, glutamate and glycine are abundant in your body. Cysteine, however, could be the bottleneck in the production of glutathione. Why? Because cysteine is a heat sensitive molecule that can be absorbed only from non-heated sources of protein such as non-pasteurized milk, non-denatured whey protein, or raw egg whites.

Amino Acids Glutamate, Cysteine, and Glycine are need to make Glutathione
Amino Acids Glutamate, Cysteine, and Glycine are need to make Glutathione

[amazon box=”B002B4D8T8″ template=”horizontal” button_detail=”https://amzn.to/3gWu6lV” button_detail_target=”_blank”]

And here’s a good one. Your body makes the amino acid homocysteine, a precursor (raw material) of cysteine. Homocysteine can be converted into cysteine in the presence of adequate levels of B vitamins, especially folate, not folic acid. Folic acid is the synthetic version of folate and is very detrimental to the immune system.

Homocysteine and B Vitamins are needed to make Cysteine
Homocysteine and B Vitamins are needed to make Cysteine

See how everything works together?

You should also avoid killing your glutathione levels. How? Acetaminophen and ibuprofen-based drugs like Tylenol and Motrin, respectively, significantly reduce your levels the glutathione, and low glutathione levels cause dysfunctional neutrophils!

And What About Sugar?

In another study, volunteers were given 100 grams of sugars in the form of fructose, sucrose, orange juice, or honey. In addition, blood samples were taken before and after their sugar intake. Surprisingly, researchers found that neutrophils’ phagocytic function was reduced by two-fold for about 5 hours.

Avoid sugary foods and drinks when sick! Sugar impairs your neutrophil function.

Diabetics’ blood sugar levels are normally high and therefore they present impaired neutrophils making diabetics more prone to bacterial infections.


The more you learn about how your body works and how it uses nutrients, the more willing you’re to adopt a healthy lifestyle. Most of the times, you get sick because you’re nutrient deficient and you’ve been abusing your body for a long time.

Vitamin D is essential. Having an indoor lifestyle works against your health because you’re meant to be under the sun. While being aware of this situation, you have to make up for the lack of sunlight but supplementing because your immune system needs it.

Turmeric also provides components that fortify your immune system by stimulating the production of Antimicrobial Peptides.

Almost everything inside of you is make of amino acids, which together make up proteins. Your antibodies are proteins! It would be a good idea to provide adequate levels of protein all the time.

And lastly, high sugar levels shut down your immune response for several hours. Avoid it, especially when sick!

Good luck. I love you all. And God bless!

Leave a Comment