Episode 07: How to Boost Your Immune System (It's Not Panic-Buying Vitamin C)
If you've ever panic-bought immune gummies or orange juice the second you felt a cold coming on, this episode is for you.
Most of us treat immune health like a fire we only try to put out once the smoke starts.
But building a strong immune system doesn't happen with a mega-dose of vitamin C when you're already sick.
It happens meal by meal, day by day, long before cold and flu season hits.
In this episode, host Sara Estes breaks down the real science behind immune system support: which nutrients (vitamin A, D, C, B vitamins, zinc, iron, copper, selenium) your immune cells are literally built from, why most immune supplements fail due to poor bioavailability and missing co-factors, and what whole-food nutrition does that isolated supplements can't replicate.
We cover:
How to naturally support your immune system year-round, not just in winter
Why zinc, vitamin D, and vitamin A work together (and why one without the others stalls)
The bioavailability gap: why your supplement cabinet might not be doing what you think
Nutrient-dense foods that deliver immune-supporting nutrients in forms your body actually absorbs
What "immuno-nutrition" means and how your daily food choices directly influence immune function
Whether you're researching the best supplements for immune health, trying to get sick less often, or just want to understand what your body actually needs—this episode gives you the research-backed framework to build immunity from the inside out.
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Ep. 07 - Immunity
[00:00:00] You know that feeling. You wake up, you swallow, and there it is, that tiny razor blade at the back of your throat. You go into panic mode, you're rushing to CVS, you're grabbing the brightest bottle of vitamin C. You can find maybe some lozenges, immune gummies.
[00:00:12] You try to flood your system with like 5000% of your daily value of everything, hoping you can just drown out the cold before it really starts I have been there. I'm actually just coming out of a cold. My toddler shared with me and being sick, sent me deep into the research.
[00:00:27] Here's what science actually says about that strategy. already too late. Your immune system doesn't work on demand. It works on retainer. Welcome to WILD IS Wise. I'm Sara Estes, a former private investigator who ditched the high stress legal life after a major health crisis. I rebuilt my health from the ground up through nutrition and functional medicine
[00:00:52] and now I'm here to uncover the truth about women's wellness and translate it so you can make informed decisions about your health. On this [00:01:00] podcast, we break down women's nutrition and physiology with real research and actionable tips, and here's the core philosophy, what's found in nature is often exactly what our biology is wired to thrive on. We get nerdy with the science, but keep it practical for everyday life. If you're ready to understand what your body actually needs, you're in the right place. As always, this podcast is educational, not medical advice.
[00:01:23] Please talk to your healthcare provider before making any changes.
[00:01:26] Let's jump in.
[00:01:27]
[00:01:29] I've absolutely done this. I've stood in a Walgreens aisle at seven in the morning holding a box of airborne packets like they were gonna save me.
[00:01:36] And I think most of us have, because we treat our health like a building, we ignore until we see flames. Ames, It's such a terrible firefighter approach. We skip all the maintenance and show up with a high pressure hose the minute we see smoke.
[00:01:48] And I'm not saying this from an ivory tower. If I sound a little extra nasally right now, it's because I am on the tail end of a cold or flu or some random virus that my toddler brought home.
[00:01:59] So I'm [00:02:00] very much in the trenches with you on this one. Being sick really had me thinking a lot about why some people seem to bounce back faster than others, and honestly, it sent me into kind of a science rabbit hole. So that's why I decided to make this episode all about immunity and specifically what we can actually do on a day-to-day to support it.
[00:02:19] And here's the thing I want you to sit with right from the top. Your immune system isn't on demand, it's on retainer. And that one shift in thinking can really change how you approach your immune health.
[00:02:31] Okay, so retainer. I know that's a funny word to use about your immune system, but stick with me because it actually changes everything about how we think about this. Today. We're gonna get into why your immune system is more like a construction site that never closes as opposed to an emergency squad.
[00:02:46] You can call when things start going sideways. We will look at what the research says about the nutrients your immune cells are literally built from. Why the form those nutrients come in matters just as much as the dose and what any of this actually looks like in your real life, [00:03:00] in a way that feels doable, not obsessive.
[00:03:02] let's get into it. Let's start with a picture of what we're even talking about.
[00:03:07] Your immune system is not a single switch. It's a layered system. Physical barriers like your skin and gut lining that act as the first line of defense. Rapid response cells that show up fast and hit hard without needing prior intel. And then you've got the smarter memory base cells that learn from what they've seen before, fine tuning their response over time.
[00:03:27] And here's what a lot of us don't know. It's running all the time. So even right now as you're listening to this feeling completely fine, your immune system is grinding away. your white blood cells aren't hanging out on break.
[00:03:37] They're constantly forming, maturing signaling, patrolling your bloodstream, identifying minor threats you don't even notice, and then renewing themselves. There's a massive turnover rate happening right now in. Your body and that turnover has a biological cost. Think of it like a construction site running 24 7.
[00:03:58] You've got a crew building a wall. [00:04:00] If you stop delivering bricks for three weeks because, well, it's not cold season yet, the wall doesn't get built, and when the storm finally hits, you can't just dump a truckload of bricks on the site that morning and yell, build faster.
[00:04:11] The wall is either there or it isn't. We tend to see immune health as a seasonal thing. It's November, I guess it's time to care about my white blood cells, which feels logical. I don't worry about fixing my roof until I see a leak, but your immune system isn't a roof that just sits there.
[00:04:24] It's a city that never sleeps and you can't activate immunity on demand if the cellular foundation hasn't been built day by day. Researchers have described your immune system as a complex integrated network that depends on multiple specific micronutrients at every stage of the immune response, vitamin A, D, C, E, the whole B family, and trace elements like zinc, iron, copper, selenium, and magnesium.
[00:04:51] They all play distinct but complimentary roles, fortifying barriers generating antimicrobial molecules, coordinating the [00:05:00] chemical signals that rally your immune cells, making antibodies, and then resolving inflammation when the job is done.
[00:05:06] And we almost never hear this in everyday wellness talk, but the amounts of these nutrients needed to optimize immune function may actually be higher than the basic recommended daily values that most of us have been told. Those RDA numbers were originally set to prevent frank deficiency diseases. The kind of sick that comes from prolonged deprivation. There's a real difference between enough to not get scurvy and enough for your immune cells to work at their very best, especially under stress, pollution and infection.
[00:05:34] Major reviews of the evidence have echoed this, arguing that poor or marginal nutritional status is a common modifiable factor in how susceptible we are to infection. The emphasis is always the same. It's not about emergency mega doses when you're already sick.
[00:05:48] It's about consistent, adequate intake over time. So if you've ever felt like well, I got the cold anyway, so nothing I do matters. I want you to reframe that the goal isn't to make you invincible.
[00:05:59] It's [00:06:00] to help your immune system do what it's designed to do. Recognize, respond, and recover because you gave it the building blocks it needed before the toddler sneeze hit you in the face.
[00:06:09] This brings us to the second big idea, and this is where I think things get really interesting and honestly a little frustrating. You probably know someone who does all the right things. They take their multivitamin every morning, they drink the green sludge.
[00:06:21] They have this like amazing pill organizer for God's sakes, and yet they catch every single bug that goes around. It's the paradox of the modern health enthusiast. You're doing all the work, but you're not getting the results.
[00:06:32] The research calls this the gap between intake and availability, and it's a critical distinction. Your immune system doesn't read supplement labels. It does not care how pretty the packaging is or how impressive the milligrams look on paper. It cares about what actually reaches your bloodstream, your tissues, and eventually your immune cells in a usable form.
[00:06:51] Just because a nutrient is listed on a label, just because you swallow the capsule doesn't mean it ever reached an immune cell to do its job. Okay, but [00:07:00] wait. If I look at the back of a vitamin C bottle and it says as sorbic acid a thousand milligrams, that is vitamin C, so why wouldn't it work? That sounds almost conspiratorial. I know here's the thing, it's not that the chemistry is wrong, it's that it's incomplete.
[00:07:17] Most standard immune supplements rely on isolated nutrients. They take a specific chemical like as sorbic acid and separate it from everything else it's found within nature and in a lab that seems efficient, you're getting the pure stuff, no filler. But in a biological system, those isolated nutrients often struggle because they're missing their co-factors.
[00:07:37] Now, co-factors, we hear that word a lot. Here's what it actually means. Think of a nutrient like a key vitamin A, zinc, vitamin C. Those are your keys, and you want to open a door, which is a cellular function, but sometimes to turn that key, you need a specific hand movement, or the lock needs to be greased or something.
[00:07:55] Co-factors are the hands and the grease. They're the helper [00:08:00] molecules, enzymes, peptides, other materials that help the primary nutrient, that key get absorbed and actually do its job. So an isolated supplement is a little like buying a car engine and just putting it in your driveway and expecting it to drive you to work.
[00:08:14] It's technically the engine, but it's missing all the wheels and the transmission and the whole delivery system as sorbic acid is just the engine block.
[00:08:22] In an orange, vitamin C comes wrapped in bio bioflavonoids and enzymes, and when you strip all of that away for the pure chemical, you're removing what helps it actually get where it needs to go.
[00:08:32] And often it just passes right through you. You're spending the money, your body is processing this stuff, but your immune system is still starving. nutrients without, their co-factors are basically just like little tourists passing through your system. They're not staying there to work. And
[00:08:46] the research is clear on this. Strategies to improve your nutritional status. Need to go beyond, just increase intake and also pay attention to the form nutrients come in.
[00:08:55] So what you're eating them with and the health of your gut. What that means in [00:09:00] practice is that you can have a cabinet full of supplements and still be under nourishing your immune system
[00:09:04] if you're not taking them with the right co-factors, your gut is too inflamed or outta balance to absorb the Mel, or you're missing key nutrients that never made it into the formula in the first place. Supplements can be extremely helpful, especially to correct known deficiencies, but they work best as an addition to a pattern where your everyday food is already supplying a broad base of nutrients informs that your body is primed to recognize.
[00:09:29] Let's get specific, because the research keeps pointing to the same cast of characters. And what's striking is just how many of these are required working together for a resilient immune system. Think of it less like a single supplement and more like an orchestra, vitamins A, D, C, the entire B family, zinc, iron, copper, selenium.
[00:09:49] They all played different. Instruments and even one section going quiet can change how the whole performance sounds. Your immune system isn't just vitamin C and maybe [00:10:00] zinc. It's a full ecosystem of nutrients and even mild insufficiency in one or more of them can blunt immune system responses across the board.
[00:10:08] Here's what each of them is actually doing. Vitamin A helps maintain the lining of your gut, lungs, and respiratory tract. Those physical barriers that are your immune system's, first line of defense. It also helps regulate the activity of your rapid response immune cells and the balance between the different immune cell types.
[00:10:26] When it's deficient, those barriers weaken and the ability to clear pathogen slows down. Think of it as a nutrient that keeps your castle walls from crumbling. Vitamin D influences both the fast response and memory layers of your immune system, including helping your cells produce natural antimicrobial compounds. Studies consistently link low vitamin D with increased susceptibility to respiratory infections, and the evidence suggests that regular supplementation, especially for people who are deficient.
[00:10:54] Can modestly but meaningfully reduce that risk. Vitamin C supports your barrier function, and acts as a key antioxidant [00:11:00] protecting cells from the collateral damage that happens during an immune response.
[00:11:04] It concentrates in your infection fighting cells and helps them go where they're needed to do the jobs effectively. And here's the thing, your immune cells are metabolic sprinters. They have enormous energy demands, and vitamin C is part of what keeps them fueled.
[00:11:17] Now let's talk about B vitamins. When your body mounts an immune response, your immune cells have to rapidly multiply and that process DNA synthesis, methylation is entirely dependent on B vitamins. Deficiencies here can impair your body's ability to produce antibodies and mount a cell level Immune response, B vitamins are basically the spark plugs for the whole operation.
[00:11:41] Everyone talks about zinc for colds, and there's a reason for that. Zinc is required for the structure and function of hundreds of enzymes and gene regulating proteins. It plays roles in the development of immune cells, cytokine production, those chemical signals that coordinate your immune response and natural killer cell activity.
[00:11:59] The [00:12:00] research also shows that zinc has direct antiviral properties. But here's the thing, most people don't show. You actually need zinc to move vitamin A out of storage in the liver and into the bloodstream.
[00:12:11] So if you're taking a mega dose of vitamin A, but you're low on zinc, it just stays parked in storage. You have the supply, but you can't get it to the front lines Now let's get iron copper. Selenium iron is involved in energy production and the actual pathogen killing activity of certain immune cells. Though it's one of those nutrients where both too little and too much can impair immunity, which is why form and balance really matter.
[00:12:33] Copper is what helps your body actually mobilize iron, move it across the cellular membrane to where it needs to go. So you could be taking an iron supplement and if your copper deficient, that iron just sits there parked in the garage. And selenium powers the antioxidant enzymes that protect your immune cells from damage during a response.
[00:12:52] Inadequate selenium can alter immune responses in ways that make viral infections more severe. More recent research has gone even further [00:13:00] describing many of these micronutrients not just as fuel or co-factors, but as actual information.
[00:13:04] Your immune cells are constantly reading messages that shape how they develop function and remember, and that information is always in conversation with your gut microbiome even how your genes are expressed. It's a dynamic, constantly running system, not a switch.
[00:13:20] You flip.
[00:13:21] The research is also clear that people with micronutrient deficiencies. Have measurable immune system impairments and are more likely to experience infections that are severe or prolonged, and that targeted replenishment can, in some cases reverse those impairments.
[00:13:36] The goal isn't about chasing perfection. It's about not leaving your immune system chronically. Undersupplied. That doesn't mean you'll never get sick here. I am still a little nasally, but it can influence how your body responds, how severe symptoms get, and how quickly you recover.
[00:13:50] Okay? I wanna be upfront about something. When I first seriously started looking at organ meats as a supplement ingredient,
[00:13:56] my reaction was not enthusiasm. [00:14:00] Liver has a reputation and if the phrase organ nutrition is making you tense up a little bit right now, I get it. It sounds intense. It sounds like something a very serious person at a very serious gym would tell you about, but stay with me because biologically liver is genuinely one of the more interesting foods you can look at through an immunity lens.
[00:14:18] Not as a cure-all and not as the only path, but as a useful illustration of what it looks like when multiple immune relevant nutrients show up together in one food, in a form that your body already knows how to use. Here's what I mean. When you look at a nutrient analysis of beef liver, you see a consistent pattern, very high levels of B12, substantial amounts of B two, B three, B five, and B six significant preformed vitamin A, heme iron in the easily absorbable form, good amounts of zinc and copper, and smaller amounts of selenium and other trace materials.
[00:14:50] Now line that up with everything we just walked through. Vitamins A and the B complex. Zinc, iron, copper, selenium, all play in critical roles in barrier [00:15:00] integrity, immune cell function, cytokine signaling and oxidative balance. And you could see why this is interesting.
[00:15:06] They arrive together, naturally balanced. They help each other get absorbed and activated. It's a package deal. That's the matrix idea. Nutrients arranged in complex structures bound to proteins, fats, other elements in a form. The body evolved to recognize and use. Think of it like the difference between hearing a single note on a synthesizer versus a full chord played by an orchestra.
[00:15:28] The isolated supplement or vitamin gives you the note, but the whole food is that full orchestra cord. Now, of course, you still can't say eat liver and you won't get sick.
[00:15:36] That's not how this works. but what we do know is that foods like beef, liver are rich in multiple micronutrients that support normal immune function, and they deliver them in a form that the body has been working with for a very long time.
[00:15:49] They're also completely optional. If organ meats are a hard no for you, you can absolutely still cover these nutrients through other animal foods, plants, and well-designed supplements.
[00:15:58] Think of organ nutrition as one [00:16:00] very efficient option inside a much bigger toolkit. And this is also why as the founder of Sara Nova, I care so much about how we deliver nutrients, not just what's on the label. But I would never want you to feel like that's the only path, food pattern, smart supplementation and organ nutrition, if it works for you, they all live in the same ecosystem. So let's land this in your kitchen, not just in the abstract.
[00:16:22] Based on everything we talked about, there are three questions worth sitting with, this is not a checklist. It's more of just a lens, a perspective that you can use.
[00:16:30] The first question is, am I covering the basics? Most days, the shift here is moving away from what can I take when I'm sick, towards what am I giving my immune system every day so it can do its job from the research that looks like a pattern of eating that regularly includes colorful fruits and vegetables for vitamin C, keratinoid, polyphenols, and fiber quality protein sources to supply amino acids and carry micronutrients healthy fats to absorb fat soluble vitamins. And for omnivores, occasionally, including nutrient dense [00:17:00] foods like liver, shellfish, eggs, and small oily fish to cover B12 vitamin A, iron, zinc, omega threes, and more for vegetarians and vegans. Being intentional about supplementation and fortified foods for things like B12, iron, zinc, and sometimes vitamin A and D become even more Important not because the diet is inherently lacking, but because some of the nutrients are harder to get in bioavailable forms from plants alone. You don't have to eat liver every day or at all.
[00:17:27] The principle here is what can you get the most nutrient bang for your bite? So your immune system isn't scraping by on the minimum. All right, question number two, am I thinking about bioavailability, not just milligrams? This is where the construction project analogy really comes to life because it's so tempting to walk down the supplement aisle and just look at the milligram count and to compare things that way. Bigger number, better deal. But researchers push us to look at something different. The biological context, the immune system is picky. It wants quality, it wants the form, it recognizes, it wants [00:18:00] nature's packaging, not just a higher number.
[00:18:02] You might be hitting the recommended amounts on paper, but if your gut is inflamed, your bile flow is sluggish, or most of what you eat is ultra processed. Your immune cells might still be under supplied. Practical ways to support bioavailability is pair, fat-soluble vitamins with meals that contain some fat when possible, mix plant and animal sources of minerals like iron and zinc, or work with your practitioner on forms and dosing. Support your gut health through fiber fermentative foods if tolerated, and minimizing things that actually chronically irritate your gut lining because a healthier gut absorbs more of what you eat. The more recent science is calling this immuno nutrition, and I know that sounds like a term someone made up at like some wellness conference, but what it really means is, this, your daily food choices are one of the most direct levers you have on how your immune system behaves
[00:18:48] specific nutrients and dietary patterns actually modulate immune function through the gut microbiome. Your fork is having a conversation with your immune cells every day. Third question. Am I consistent enough that [00:19:00] my immune system can count on it? the research is clear. Maintaining optimal nutritional status over time is more effective for supporting immune defenses than sporadic high doses. When you're already sick, as we said earlier, the episode,
[00:19:12] you can't dump a truckload of bricks on the site the morning of the storm and expect the wall to be there.
[00:19:17] In practice, that might look like building default meals that usually include a protein, a plant, and at least one nutrient dense ingredient. Planning one or two micronutrient rich meals per week, so maybe like a liver dish, a seafood night, maybe a big mixed color salad with some seeds and eggs,
[00:19:34] and using supplements intentionally to fill known gaps like vitamin D in the winter, or iron if you're deficient. All of this in conversation with a practitioner, do that instead of hoping a random stack will cover everything. Thing
[00:19:45] As I'm sitting here with the last of this toddler cold still lingering in my voice, I keep coming back to the big picture. We've spent this whole time on immunity, but if we accept the premise that our bodies are evolved to recognize nutrients and complex food matrices, not [00:20:00] isolated chemicals, it raises a question. We're thinking about how many other areas of our health are we falling short in simply because we're trying to outsmart nature. We try to hack our sleep with isolated hormones, our digestion with isolated fibers. But maybe the answer isn't a better hack.
[00:20:16] Maybe the answer is just better incorporating and mimicking nature's original design. If the nutrient matrix is key for immunity, where else are we missing it? That's a lot to chew on, and I don't have a tidy answer, but I think it starts with this, stop thinking of immunity as a seasonal panic button.
[00:20:33] Start seeing it as something you're slowly building, meal by meal day after day. Your immune system is rebuilding itself out of whatever you give it today. It's a construction site that never closes. The more you can give it a mix of these key nutrients in the forms your body recognizes.
[00:20:50] The more you're supporting the crew that's been looking out for you all along.
[00:20:53] And when the storm comes, because it will come, you won't even worry about it. The wall will be there. Alright. That's it for [00:21:00] this episode of Wild As Wise. Thank you so much for listening. I hope you found this information useful and helpful. Next week we're going to be diving into five super herbs that help with your gut health. I'm so excited to talk about this. So until then, stay wild, stay wise, I'll see you next week.