A Healthy Immune System - The Essential Nutrients

A Healthy Immune System - The Essential Nutrients

A Healthy Immune System - The Essential Nutrients

We all know that the prevalence of illness goes up in the winter. There are different theories about why that might be - we are together indoors more often so are more likely to spread germs, we are not getting outside as much so we are missing the sunshine and fresh air, it is darker in the evenings so we feel more lethargic, or the cold air dries out the protective lining in our noses so we are more susceptible to germs. I have no idea which theory is correct. But, I do know that whatever the reason, we can be proactive in taking care of our immune systems so we are better equipped to fight off whatever bugs we might encounter. 

One important way to do this is to make sure that we are ingesting the vitamins and minerals that are essential for immune health. Let’s take a look at what those are, why they are important, and where we can find them. 

Essential Vitamins for a Healthy Immune System

Vitamin C

We have all heard about this one - it’s the go-to for fighting off colds!

And here’s why…Vitamin C acts as an antioxidant, which means that it neutralizes free radicals and protects our cells from damage. Free radicals are unstable atoms that are produced through metabolism and by toxic chemicals. In excess, they cause diseases, damage cells and accelerate aging. Our immune system is equipped to fight them off, but it needs to be primed correctly. That’s where Vitamin C (and several other nutrients we will look at) come into play. 

In addition to its antioxidant properties, Vitamin C also assists with the production and function of white blood cells (the cells that are produced by our immune system to fight infections). Clearly, this one is a must for a strong immune system!

Sources of Vitamin C include: citrus fruits, peppers, broccoli, strawberries, brussel sprouts and potatoes. 

Vitamin D

This one has gotten a ton of attention lately, and for good reason!

Vitamin D plays an important role in modulating our immune system. That means that it influences the way our immune cells (specifically the T cells and macrophages) react in the face of a dangerous bacteria or virus. But that’s not all! Vitamin D also enhances the production of antimicrobial peptides (the bits of proteins that eliminate dangerous microorganisms) which our bodies need to defend against infections. 

Sources of Vitamin D include: SUNSHINE (or SAD light), fatty fish, fortified milks, beef liver, eggs.

Vitamin E

Vitamin E is another one that works as an antioxidant. Remember that antioxidants protect the membranes of our cells from the damage of free radicals and help to maintain the integrity of the immune cells. Vitamin E is also responsible for supporting the activity of our immune cells, especially T cells (white blood cells that develop from our bone marrow and fight infections). 

Sources of Vitamin E include: sunflower seeds, almonds, walnuts, red bell pepper, spinach, collard greens, mangoes, avocado.

B Vitamins

 This is a group of eight different vitamins. All are important in their own right, but are usually grouped together. These work to support the production of antibodies which are the proteins created in our immune system that bind with foreign or unwanted substances and remove them from our bodies. We definitely want a healthy dose of antibodies when we need them!

Additionally, B Vitamins are needed for the development and maintenance of our immune cells.

Sources of B Vitamins include: meat (especially liver), seafood, poultry, eggs, dairy products, legumes, leafy greens, seeds.


Selenium is a mineral that’s found in our soil and we only need a tiny amount of it for it to do its job. Like Vitamin C and E, selenium is an antioxidant so it fights free radicals and protects cells from oxidative stress. It also helps to make sure our immune cells are functioning well and that our immune responses are well regulated (not over- or under-reactive). 

Sources of Selenium include: Brazil nuts, organ meats, spinach, beans, seafood.


Zinc is essential in the activation of T cells in our immune response. The production of T cells is part of our adaptive immune response which is where we create antibodies that target specific germs or bacteria. (As opposed to the innate immune response which is the first line of defense and does not differentiate between pathogens). Also, like the B Vitamins, Zinc is involved in the production of antibodies. But, unlike other nutrients we have talked about, Zinc has special antiviral properties. This means that it can inhibit the replication of certain viruses in our systems, which is always a good thing, especially when we are trying to shake off a cold or flu virus!

Sources of Zinc include: oysters, beef, pumpkin seeds, oats, sardines, eggs, salmon. 

Fighting Illness in the Winter Months

Just as there are many theories about why sickness increases in the winter months, there are a lot of thoughts about the best way to get the proper amount of nutrients in our systems. While whole foods provide the most bioavailable nutrients, there are studies showing that the fruits and vegetables we eat today have a much lower amount of nutrients than they used to because we have depleted the soil they are grown in. Also, as much as we know that it’s important to focus on whole foods, the truth is that most of us eat plenty of processed foods which are notoriously low in these nutrients. 

So, now we get into the question of supplements. Do they help or hurt? Is our body able to absorb the nutrients when they are not in their natural form? Is it damaging to our livers if we take too many? How do we know what to take? How do we know how much to take? How do we choose which brand to take? 

All of these are good questions, and the honest answer is that I don’t know the answers that are right for you. But, I do know that your body knows what it needs and what is damaging to it. So, pay attention to what your body is telling you - it speaks volumes!