Dr. Libby Weaver | The Forgotten Supernutrient article

In this episode of the Smarter Not Harder Podcast, Dr. Libby Weaver gives us one-cent solutions to life’s $64,000 questions that include:
Why is iron deficiency so commonly missed in women, children, and athletes, even when standard blood tests fall within the normal range?
How do inflammation, elevated hepcidin, and poor gut health block iron absorption even when dietary iron intake appears sufficient?
Why can low iron contribute to anxiety, poor concentration, low resilience, thyroid dysfunction, and impaired neurological development in children and teens?
What are the risks of relying on high-dose iron supplements or repeated iron infusions without addressing root causes like absorption, inflammation, and nutrient cofactors?
How can food-first strategies, proper testing, and modern iron supplementation approaches support long-term energy, immune function, and athletic performance?
Who is Dr. Libby Weaver?

Dr. Libby Weaver is a nutritional biochemist, bestselling author, and one of Australia’s leading voices in evidence-based, integrative health. With a background that spans nutrition, dietetics, and a PhD in biochemistry, Dr. Libby brings deep scientific rigor together with decades of clinical experience. She is known for her ability to translate complex physiology into practical, empowering insights that help people better understand their bodies and reclaim their health.
After spending 14 years at university and more than 25 years working one-on-one with clients, Dr. Libby developed what she calls her three-pillar approach to health: biochemical, nutritional, and emotional. This framework reflects her belief that physical symptoms, mindset, and lived experience are inseparable. Her work focuses on identifying root causes rather than managing symptoms, with particular attention to fatigue, stress, hormonal health, resilience, and the long-term consequences of nutrient deficiencies that are often overlooked in conventional care.
Dr. Libby is the author of several acclaimed books, including Fix Iron First, which has helped bring global attention to iron deficiency as a driver of anxiety, poor energy, impaired cognition, and reduced performance across all stages of life. She is also the founder of Bio Blends, a whole-food supplement company designed to support the body using nutrients in their most bioavailable forms. Through her writing, clinical insight, and public education, Dr. Libby continues to challenge outdated narratives in healthcare and advocate for smarter, more compassionate approaches to healing.
What did Dr. Libby and Jodi discuss?

00:00 Intro & why iron deficiency is still misunderstood
02:45 Dr. Libby Weaver’s background and why biochemistry matters
06:10 What iron actually does in the body beyond oxygen transport
10:05 Why “normal” iron labs often miss functional deficiency
14:30 The role of inflammation and hepcidin in blocking iron absorption
19:40 Iron deficiency in women, children, and adolescents
24:55 How low iron impacts anxiety, focus, mood, and resilience
30:20 Iron deficiency, hormones, and thyroid function
35:45 Athletes, performance, and the hidden cost of low iron
41:10 Risks of iron infusions and high-dose supplementation
46:35 Food-first strategies to rebuild iron safely
52:00 Testing smarter and personalizing iron support
57:30 Final takeaways and how to fix iron first
Full Transcript:

Libby Weaver: [00:00:00] Anxiety is a symptom of iron deficiency. Anxiety can be a symptom of all sorts of things, but it is a symptom of iron deficiency. So there's that. Then of course there's the absorption issue. So, uh, so for so many people today, they live with chronic inflammation, and I can imagine that you see so many people experiencing that, whether it's from too many lousy lifestyle choices, it might be from injury.

Libby Weaver: So that they live with this chronic inflammation.

Jodi Duval: Right. I am so honored to have the incredible Dr. Livy Weaver here with me today, and thank you so much for your time, Libby. 

Libby Weaver: Oh, Jody, thank you for having me join you on your podcast. 

Jodi Duval: Oh, it is very, very exciting. And I was saying just off recording that. Iron is one of my most favorite things to talk [00:01:00] about because I feel that we really miss the piece on a lot of intricacies of how we look at iron, how we prescribe iron, and particularly with women and even children.

Jodi Duval: A huge part of my practice is also pediatrics. So it is a, it's a big thing and I am constantly trying to correct and talk and, um, inform clients and about their kids as well in regards to this. So. Really excited to talk to you about this. So you have an incredible book out. Fix Iron First, which I'm like, yes, go Libby.

Jodi Duval: This is what we need.

Jodi Duval: So tell me firstly a little, 'cause first time on. The podcast. So tell me a little bit about you, Libby, and for the audience. Where have you come from? Where have you landed in, why, why this, why the passion that you have around nutrition, biochemistry. Um, so tell us a bit of your story First. 

Libby Weaver: Oh, you're so lovely, Jody.

Libby Weaver: Thank you. And can I just [00:02:00] say, health just radiates out of your face and your eyes? It's just, you know, I know we're on Zoom right now, but it's just Yeah, you are. You're so electrified. You're so alive yourself. So it's just, yeah. Extra gorgeous to talk to you. So my little, my little bit of my background, and I think it is helpful for people to hear this because it'll help listeners to understand the lens, I guess.

Libby Weaver: Through which I look out upon everything when I'm, you know, working with people. So I grew, I grew up in Tamworth, in country New South Wales. Uh, and uh, we lived very simply. We had chickens in the backyard, grew some of our own food, but not much. It was just a small, little, little plot of land in town. Uh, and then I went to uni for 14 years, which I know makes me sound really thick and like I failed everything.

Libby Weaver: But I very much love learning. I still do. Uh, so I originally studied nutrition and dietetics and then did honors and then did a PhD in biochemistry. So lots of science there in [00:03:00] my background, but since then I've worked with people one-on-one for 25 years, and that's, as I'm sure you agree, Jody, that's where you get to see what really makes a difference in people's lives and also what doesn't.

Libby Weaver: And so I've combined. My 14 years at uni with my clinical experience to create what I call my three pillar approach. And those three pillars are the biochemical, the nutritional, and the emotional, or you could say mindset. So I look at everything through those three lenses. Yes. And my latest obsession, uh, it kind of has always been my obsession.

Libby Weaver: I just sort of didn't feel. I had the, the complete story to, oh, we don't think we ever have the complete story. But I felt like I didn't have a full enough story to share it. But I'm absolutely obsessed with bringing iron back to the top of the pile of the conversation list. 'cause I think for a lot of people, they've forgotten about it.

Libby Weaver: It is the most common nutritional deficiency in the world, and other nutrients have kind of become trendier. Everyone's aware that magnesium matters and vitamin D and Creatine's having its moment. So there's all these things that kind of. [00:04:00] Get the spotlight and we are forgetting about iron, unfortunately.

Libby Weaver: So I want to change that. 

Jodi Duval: Absolutely. And I'm right there with you. And like you say, you know these things firsthand in clinic, what works, what doesn't, and then why and how the missing pieces are coming in. And you, you know, as a, as a clinician, you're there trying to advocate as much as you can to get the most incredible changes for the people in front of you.

Jodi Duval: And then when that's not working. And you're missing something, then you are driven to go down different avenues and really look at that. Yeah. And I love your three pillar approach. I think we can't separate. Um, and once you've worked in practice for some time, you realize there is no difference between the emotion and the physical symptoms that are arising in clients because they are.

Jodi Duval: The same and whatever chicken and egg it is, it's always arising from all of that together. And then the biochemistry is just for us nerds. It's just something that really makes us tick. Uh, yeah. So, so good. So, all right, let's dive [00:05:00] into I am, I, I find, um, that there is a, a general miscommunication. Um, as you'll expand on for us, and I love that you talk about hepcidin.

Jodi Duval: Hepcidin does not get a conversation much, any or at at all, really. And I talk to doctors about it, gps, and they look at me with a blank. Like, what you don't even know how to do. I am. Okay. So talk, talk, talk us through all of it. There'd be like from start to finish in terms of like what you've seen, why you started to get really passionate.

Jodi Duval: Um, you know, what we see coming from iron deficiency, and then we can dive into the nuances of how we look at it and then prescribe, and then, you know, it's an intricate. Biochemical setup, isn't it? It's something that takes a lot of consideration in the body, so yeah, talk us through it. 

Libby Weaver: It does. So obviously fir the first reason I think that too many people are deficient these days.

Libby Weaver: I actually think inadequate dietary intake is a major [00:06:00] contributor, and I think women across se menstruation years, especially underestimate how much iron they actually need to meet their requirements. Obviously, if periods are heavier. Those requirements can be even greater. But obviously I'm a fan of getting to the root cause of something, so why is someone having heavy periods in the first place?

Libby Weaver: And let's see if we can change that. But all of that aside, so our iron requirements, obviously, um, we are born, we go right back to the start. So when little humans are born, they, they accumulate iron in their liver in the third trimester of being in mom's tummy. And so if a baby is born prematurely. And, and also if they're born to a mother with low iron stores, that baby begins life usually without enough iron, certainly without enough iron stores to get them through to around the six month mark when complimentary foods are introduced.

Libby Weaver: So, and I feel that that's being missed. Obviously that is a job for pediatricians to, to address that in those little baby humans. But I feel almost the, the awareness of it. [00:07:00] Has that has fallen away. But then obviously when, when those foods, uh, solids are introduced around the six month mark, I worry that too many mothers aren't aware of how crucial the iron needs are there.

Libby Weaver: So they're around 10, 11 milligrams per day for that little baby human to grow and develop. And when little babies are iron deficient and they grow up that way. Their IQ is, is affected, their cognition, their development, their ability to concentrate and focus. Uh, and I worry too, Jody, to be really frank, I do worry that sometimes, uh, as kids get a bit older, they're often diagnosed with a psychological or a psychiatric condition and iron deficiency being missed, I think in too many kids.

Libby Weaver: So our needs. As we grow up, sort of sit around that 1110 milligram mark per day. And then of course once menstruation starts for girls, it goes up to 15 and then to 18 milligrams per day. And if someone eats [00:08:00] in a vegan or vegetarian way, we have to multiply that RDI by 1.8 for a host of a host of reasons.

Libby Weaver: So not eating enough, I think is the first thing, and I, I will just add. I worry hugely Jody about teenage girls because it right at a time where they actually require more iron. A lot of them are being influenced often through social media to head in a plant-based direction and you can get enough iron if you eat plant-based.

Libby Weaver: But you really need to know what you're doing to be able to meet those requirements. And they're not getting the education, they're just cutting out meat and thinking that that's, that's the thing to do. And their iron requirements plummet as a result of that, right? When they need more Anxiety is a symptom of iron deficiency.

Libby Weaver: Anxiety can be a symptom of all sorts of things, but it is a symptom of iron deficiency. And again, I worry particularly for those teenage girls that it gets missed. So there's that. Then of course, there's the absorption issue, so. So for so many people today, they [00:09:00] live with chronic inflammation, and I can imagine that you see so many people experiencing that, whether it's from too many lousy lifestyle choices, it might be from injury.

Libby Weaver: So that they live with this chronic inflammation, and as you mentioned, one of our favorite subjects is hepcidin. When there's any kind of inflammation going on, hepcidin increases and hepcidin a good way for people to think about it. The liver produces it and it's like the bouncer at the stadium. So it's the dude who says iron.

Libby Weaver: You're allowed in or iron. You can't come in. So Hepcidin is responsible for either allowing iron absorption or blocking it. And hepcidin is increased when we have enough iron already in our body and our iron stores are great. So hepcidin will naturally elevate, but it will elevate when there's inflammation.

Libby Weaver: So even if someone is. Doesn't have good iron status, their hepcidin will elevate if they have, if there's inflammation going on and actually block iron, uh, being absorbed. So we have to [00:10:00] understand that living with inflammation can have all sorts of unfavorable consequences, but one of them is a disruption to really healthy iron metabolism.

Libby Weaver: So I think too, so when we, as far as gut health goes, it can have a dramatic impact as well on whether we absorb iron well or not. So some people, uh, have, they know they have celiac disease. Some people actually find out they have celiac disease because of persistent low iron. Or they might have, uh, other digestive system challenges that is interfering with iron absorption.

Libby Weaver: I won't, when we talk about supplements, I'll go into the actual mechanisms of iron absorption for the different types of iron. Um, but that's another factor. And then of course, the other reason why people can be low in iron is from significant blood loss. So whether that is through really heavy periods, um, often through perimenopause, women start to.

Libby Weaver: Bleed more frequently or periods can get heavier and there's more iron loss, of course when that happens. And if they've got low [00:11:00] ferritin, uh, or low end normal ferritin, I call that the backup battery. There's sort of not, not enough there to keep supply going and all sorts of other things can be affected.

Libby Weaver: We need iron, for example, to literally be able to produce thyroid hormones. A really common scenario I've seen is women with persistently low iron or low end normal iron and heavy periods, and then their thyroid starts to underperform in their forties, and that doesn't come out of nowhere. I see that that's a cumulative effect of a.

Libby Weaver: What we just kind of put up with is what too many women just put up with because it's sort of, it's not a disease, so nothing's diagnosed, so therefore there's no sort of solution or support offered unless they're working with someone like you, Jody. So there's not that. Awakening to, oh, what do you mean I don't have to live with this?

Libby Weaver: Do really? Do I not have to put up with heavy, painful clotty periods? What do you mean? Once my thyroid starts to underperform, are there things I can do to change that? And obviously iron is one of the [00:12:00] things. There are numerous, but iron is one of the big factors that women, I think, need much greater awareness of the long-term consequences of living with not enough of it.

Jodi Duval: Mm, absolutely. Well, so many pieces to unpack there. But I think the important part, um, I really, uh, appreciate you talking about is I think the nuances around iron. 'cause I see it's, it's stubborn. You know, I see a lot of women coming back years after year, after year after from their doctor not getting anywhere with a current supplementation.

Jodi Duval: You'll get to that 'cause there's definitely a nuance around that. But also just feeling like they can't get anywhere. They get infusions and it look straight back down again within a year or two. And it's frustrating. And then also it is taking the impact of, of having that low iron consistently in the body.

Jodi Duval: You know, that that constant demand, like you say, that the body is trying to fight up against, it's not all the building blocks there ready for it. So it's taken away from other organ systems, from other areas and like we know it's an, it is an essential, iron is so essential. In the wrong [00:13:00] doses. It can be highly toxic as well, you know?

Jodi Duval: Yep. So we need to also consider the, the, the issues associated with continual use of these IV therapies with iron, um, and also dosing the wrong ones. So, but I think what I, what I think a really important part to, to sort of pull apart is the, the teenage girls. Uh, I've, I've noticed it in my practice and it's getting scary.

Jodi Duval: I actually had a, a couple of conversations just this week, um, with parents and. I know anxiety is huge and we know hormones are shifting. You know, I, I liken the, the puberty stage for a woman to be like perimenopause. And generally the moms going through perimenopause have the teenage daughters that are going through puberty.

Jodi Duval: And it's, it's a similar shift, um, in terms of emotions and change and hormones. But what we, what I'm seeing more, and it's devastating is the anxiety, the social anxiety, um, the issues with, with coping. We now have, um, you know, suicide rates. On the rise. Um, I'm seeing some very, I'm hearing [00:14:00] some very scary, scary things particularly about around ai.

Jodi Duval: I just saw something come out in the media, but it was a conversation I've had in the last couple of weeks with a, with a client myself. Um, but again, it's like from what I see in practice. It's, it's can be such easy fixes if picked up. And it's really sad that we, we, we need an understanding of how simple a deficiency state of something can become so huge.

Jodi Duval: And it's just, for me, I'm passionate like you, I'm just like, are you, we, we, we need to address this because we are missing and we are losing like. Beautiful people if we don't actually see this. So I think that's a really important point you made there, is that, um, you know, the, the, the puberty stage and actually equipping our teenagers, particularly the women with the, the coming on of loss, loss of blood, which escalates these symptoms in such a profound way.

Jodi Duval: Yeah. Um, all right. So. Let's talk about a bit more on [00:15:00] mechanisms. Let's talk about, um, and if you wanted to align this with the types of iron supplementation that you're seeing. Also would love, uh, um, your perspective on the IVs. And we can talk about that because it's a very quick to fix, um, s scenario that we see a lot.

Jodi Duval: And, um, a lot of gps I hear commenting to my clients. Um, firsthand saying, oh, don't worry, we'll just, we'll just do this every year. It's fine, you know, and so it's not really that root cause look. So I'd love to hear your perspective on all of that. 

Libby Weaver: Mm, Jody, thank you. Yes. Uh, do you know? So I feel that we're, we are really fortunate to live at a time where we have access to amazing emergency medicine.

Libby Weaver: So obviously an iron infusion can save someone's life, you know, if they find out that it's rock bottom or there's, you know, significant blood loss and a blood transfusion hasn't sorted things, it's so that it, it's really remarkable. But in my opinion, that's when it needs to be used. In an emergency, what I worry about is women who use, [00:16:00] uh, don't address what's going on with their own iron status, and they just use iron infusions as their solution, so they don't address either the not eating enough iron rich foods, they don't address.

Libby Weaver: The absorption issues, they don't address the heavy bleeding. So in other words, the things that are actually causing them to be iron deficient, they just go, oh, I'll just have an infusion every six to 12 months and that's my way of having enough iron. But when you think there's all sorts of challenges with that.

Libby Weaver: So firstly. When you have that big infusion, it, the delivery obviously is straight to the blood. Now iron, just like everything in the body, doesn't act on its own. So for iron to be able to go where it needs to go to the bone marrow, for example, so that we can make brand new red blood cells and to blow everyone's minds and to help people live with, to help people be in just a little bit more awe and wonder with their body.

Libby Weaver: We make two and a half million new red blood cells every second. So it's just [00:17:00] extraordinary. And iron needs to be in all of them because those little red blood cells, the iron allows them to carry oxygen to every cell in the body to do its cri critical work. And life with low energy is pretty challenging.

Libby Weaver: The ripple effect of it is major because it means when we're tired, we may not necessarily go for a walk. We might not feel like we have the energy to cook dinner, so we get takeaway. We might not. Phone a friend and so we sit with more feeling, more feelings of loneliness. Or it might be we don't apply for a job promotion or it, it might impact the way we speak to the people we love the most in the world.

Libby Weaver: So I feel like we, people gloss over. Being tired and I kind of try and expand the conversation around that a little bit just to think about what life would be like if more of us lived with better energy and the our, not just our ability to take care of ourselves and the choices we we make in regards to ourselves, but also the way we interact with others, show up with others or what we believe we are capable of.

Libby Weaver: I think iron is. Hugely, a hugely linked to [00:18:00] resilience. I think it's hugely linked to confidence and part of that obviously is through better energy and through those really healthy red blood cells being able to, to deliver that oxygen. So that's just one little thing. So when we have those iron infusions, uh, the iron alone.

Libby Weaver: It's just having iron alone. It's not enough to get it to where it needs to go. So copper and vitamin A are two nutrients that are crucial to really healthy iron metabolism. In other words, once iron is inside you, you then need copper and vitamin A for it to be the iron to be able to go into storage, to be delivered to the bone marrow, to be transported to everywhere it needs to go, including to.

Libby Weaver: Do things like make thyroid hormones, make neurotransmitters like serotonin and melatonin for sleep, and GABA for the calming factor and dopamine for motivation. So it's gotta be able to get where it needs to go. And when we just have an iron infusion, we're not being given this the right amount of copper and vitamin A to help the the iron do what it needs to do.

Libby Weaver: A big dose of [00:19:00] iron can also induce inflammation itself. It can also create what are called the generation of. Reactive oxygen species. So essentially free radicals. And the way we protect ourselves from damage against free radicals is we need to consume enough antioxidants, which are essentially in our colored plant foods, in, in our veggies especially.

Libby Weaver: And as Australians, we're not very good at eating enough vegetables, but that's a conversation for another day. Uh, anyway, so that's kind of my gist with iron. Oh, sorry. The other point I'd love to make around iron infusions is. Sure the levels get topped up, but if you don't, then also address why it's, why you were deficient in the first place, it will fall again.

Libby Weaver: And you live with so for so long, for too long with suboptimal iron levels so that then all the things inside you that iron is needed for their function is essentially compromised. Mm-hmm. So it's, it's not a solution in, in my opinion, the infusions are great for emergencies, but not as, as a, as [00:20:00] a lifestyle choice.

Libby Weaver: That's partly my worry. 

Jodi Duval: Yeah, I totally agree. As you're saying that, I'm also thinking about the way that we test for iron as well. And I think I look, I look at this and I know you speak about it as well, but with inflammation obviously can give false readings of some sort. So it al it always depends on, um, you know, context around testing, but I, I also, um.

Jodi Duval: Question myself, the retesting after an infusion and how much inflammation is still present and therefore how much that's driving false readings and therefore, what is really, truly cellular levels and storage levels. And then, you know, therefore, suboptimal levels could be a lot longer than we actually think, or actually not even getting a full capacity of iron where we need to.

Jodi Duval: I think we, and what I've come to realize over my years of practice and study and looking is that we, we try to make it simple, but we can't, we have to be looking at the complexities of all these things to make full sense of them all. So yeah, I think that's, [00:21:00] um, yeah, something that I, I, I've been noticing.

Jodi Duval: Have you have he also, yeah. 

Libby Weaver: Yes. And that's so beautifully said, Jody. I think, uh, when it can absolutely be falsely elevated, particularly ferritin. So to put that into context for listeners, your blood test might show that your ferritin is 150 after an infusion. But is it really, is it really more like 40 and the inflammatory markers?

Libby Weaver: So interleukin six, one of the, um, inflammatory cytokines is the one that's known to, to elevate with. The inflammation related to what an eye infusion can do. So is that falsely masking that ferritin level? And it's not actually that high. Maybe it is, but we can't, it's, we can't, we actually can't know in that case, after an infusion.

Jodi Duval: Hmm. No, absolutely. Even the current testing, I think, you know, there is, um, maybe even a lot of missed iron according to. You know, symptoms, obviously people are feeling unwell. Like you said, there's tiredness, there could be viruses, it [00:22:00] could be tested at the wrong time. So it comes back, oh, you're fine. It's not iron.

Jodi Duval: But when you actually then test at a time that they're not inflamed and you haven't done those cytokine markers at the same time, so you really don't know, and therefore you've completely missed it. And they go for years still without having proper iron levels. So yeah, there's a lot. 

Libby Weaver: There is a lot. And then you add to that, that if someone's tried.

Libby Weaver: One of the old school iron supplements. A lot of women especially get constipated when they take those. And so I've had lots of people say to me, I would rather be iron deficient than constipated. So they, if they think that iron. Those old school iron supplements are the only solution. They'd kind of, yeah.

Libby Weaver: They, they don't want to go there, so, and it's why the, the, there's a whole new generation of supplements now available that aren't constipating, which I can speak to in a moment. But, so people understand that the, the old school supplements where they're dosed at a really high level, so some of them are a hundred milligrams of iron or even, even [00:23:00] greater, uh, in one tablet, and it's just way too much in one dose.

Libby Weaver: So we know that when we have such a large dose of iron orally, it will induce hepcidin straight away. And obviously, as we just talked about, hepcidin blocks iron absorption. So when hepcidin is elevated, it blocks iron absorption when hepcidin iss nice and low. It allows for iron to be absorbed and large doses of iron will elevate that hepcidin.

Libby Weaver: So, um, and also too, with those old school supplements, they're usually iron bound to a salt or a chelate. And so when we swallow them, the stomach acid pulls apart the iron. From the keate or the salt, whatever it's bound to. And then that free iron arrives at the cell, at a cell that lines the small intestine.

Libby Weaver: And on the surface of that cell is a little, I get people to imagine it like a little truck, a delivery truck, which is, it's a transporter and it's big, long, silly name is abbreviated to DMT one, and the iron has to hop on the back of that truck and the DMT [00:24:00] one will drive it inside the cell. But the trouble with that is, firstly, you need to have enough DMT one trucks available and DMT one trucks are used for the absorption of other minerals like calcium and zinc and copper.

Libby Weaver: So all of those minerals will compete with iron for absorption. 'cause they need, they all need the trucks, so we need good, good number of trucks and no interference from those other minerals at that time. Also too, once the trucks take the iron inside the cell, the gut cell is then exposed to free iron.

Libby Weaver: And, and with those old school supplements, it's often a really big dose of free iron, and that's, that floods the gut cell with, with free iron, driving inflammation, driving the creation of those reactive oxygen species. So those free radicals, and that's part of what creates the gut related symptoms, the constipation, the nausea in for some people with a pain that they described from taking those conventional supplements.

Libby Weaver: So we can geek out even further. Um, if you can imagine that the iron is [00:25:00] inside a cell that lines the digestive system, I want people to imagine that it's still not in the blood, which is where you need it. It still hasn't got out the back door of the gut cell and at the back door of the gut cell, a copper dependent enzyme is needed to actually get the iron out of the cell and transport it.

Libby Weaver: So. Some people might be getting enough iron, but they're copper insufficient, so there's not enough of those enzymes available to actually get the iron out of the cell and take it to where it needs to go. But the good news is that there's, there are new supplements now available. What I encourage people to look for is ferritin iron, and it's been extracted from peas.

Libby Weaver: And then concentrated into supplemental form and ferritin iron. When we take it as a supplement, we swallow it. It's not reliant on stomach acid for absorption. And too many people today, which is good 'cause too many people today don't have great stomach acid production, I don't think, from persistent stress.

Libby Weaver: And then when the ferritin iron is delivered to the gut cell wall, [00:26:00] it's actually absorbed through. It's a geeky, geeky name, but receptor mediated endocytosis, and all that means is the cell reaches out and grabs onto the ferritin cage, which contains all of the iron molecules and takes it inside the cell.

Libby Weaver: But because the iron is all housed inside. The ferritin cage, the, the gut cell is never exposed to free iron. So you don't get that awful inflammation and reactive oxygen species. And then it's taken into the, the, the total iron pool and, and delivered directly there. So that's very exciting. So I, if people need supplementation, that is what I encourage them to look for.

Libby Weaver: Ferritin iron. And also, um, the, the beauty with that is the doses, there are clinical trials have been done looking at, uh, women with. Iron deficiency anemia, and they were only given five milligrams of ferritin iron per day for four weeks, and it got them out of their blood parameters being in that anemia [00:27:00] place.

Libby Weaver: And then they kept going for another five weeks in that clinical trial. So a total of nine weeks. And for this, for the five week period. They only had 10 milligrams per day of ferritin iron. And again, the improvements in blood levels for every participant was, uh, significant. So it's certainly, I think probably the future of supplementation without those awful side effects.

Jodi Duval: Yeah, absolutely. Yeah. The limitation of supplementation is a big one. Um, and I see that here in clinic we don't have availability. I'll look into that fer, ferritin iron as well, because I currently use an iron bis glycinate and it, and it's good. And I, I still have to be aware of the fact that we're dosing correctly for, like you've just mentioned and given such a good description on, is we're not rising that hep.

Jodi Duval: Level because again, I'll dose every second day if I need to, to make sure hepcidin has fallen again and lowest in the morning. So making sure that that's, um, appropriate. But if we are having not higher levels of the, the ferritin and also that's getting absorbed quickly and not reaching those areas where it's going to [00:28:00] start to inflame, then you can dose every day.

Jodi Duval: So yeah. Very, very interesting. Hmm. Yeah. Very good. Okay, so with the a, again, I think transporter and then you've got, you know, the, the, the trucks, which I, I love that you explain it in that way. I, I talk about buses and I'm like, there's only a certain number of, of seats on that bus, so I just love that you're using technology too, but mineral.

Jodi Duval: Yeah. When we talk about mineral and the competition, you know, a lot of. Zinc and copper get a lot of time, right. But we don't normally align iron with that in terms of common conversations and ratios that we look at all the time. So I think reeducation needs to be around that as well. I find that to be a really, really important piece in wa We're quite lucky we have, uh, generally a too much copper going on, um, because of our beautiful pipes that are, that are still lying in the ground.

Jodi Duval: But we, we have to be aware of different factors around that too. But everywhere else in the world, including eastern states of Australia, I find that copper can be a very, very common [00:29:00] deficiency. So, yeah, I, I, I think that is the other things that we think about that aren't so simple. You know, that's, that, that common, you know, connecting pieces that help iron.

Jodi Duval: Um, all right, so the other thing that you mentioned a little while ago, and I think I I'll bring that back in now just a little bit, is Celia. And so. Absorption issues, celiac, and then a general inability to absorb these ar these at these areas that we talk about 'cause of the damage that's being done.

Jodi Duval: And so I see this, uh, a lot happening, um, in clinic in higher rates now as children being diagnosed with Celiac. And I think it's, it's, um, all to the fruition of the, the parents really pushing for that diagnosis. But if not, then it gets missed quite easily. And then, like you mentioned, underdevelopment of children and, you know.

Jodi Duval: You thinking hair loss. We, we have so many symptoms that are associated with iron. So you know, where, where, how do you support and help those who have celiac, like what are your recommendations around even dosing iron [00:30:00] if they need to, and supporting that. Obviously there's the healing and removal of gluten.

Jodi Duval: Um, but yeah. What, what do you look at in clients there? 

Libby Weaver: So firstly, obviously the diagnosis is key. Uh, and but in saying that, Jody, I do worry that. Celiac disease is the me is one of the mechanisms of a reactivity to gluten that we re, that we understand pretty well now, but what if there are 20 others or 50 others, and we don't know those mechanisms yet.

Libby Weaver: So for me, just because someone is. You know, may test negative to actual celiac disease. If their gut related symptoms vastly improve when they eliminate gluten containing foods and gluten containing foods. Then for me, the, the body doesn't lie. So it might not, and if they've been tested for celiac disease and it's negative, and yet a lot of their gut related symptoms improve, I would still say to that person, you are much better off eating in a [00:31:00] gluten-free way, but just because we don't have a test right now, that can work out whatever your mechanism of sensitivity is, and it might be lifelong, but it also might not be so with some other gut healing kind of work.

Libby Weaver: Whether that is actually really focused on the gut or if that's more emotional, uh, because you might gut for obviously so many people, their gut related symptoms kick in after the chronic production of stress hormones after some really tough times, or it might kick in. After they travel to a foreign country and they get food poisoning or they drink water and they get what they would think of as just food poisoning, but then their gut function is never the same again.

Libby Weaver: We see celiac disease itself triggered obviously after some kind of infection. That's incredibly common now. So whatever it is that is leading to the person to not be able to digest gluten well. Whether it's full blown celiac disease or not. The omit [00:32:00] of gluten I think is obviously a key step for some, not all, but for some people in to, to actually heal their gut.

Libby Weaver: So that's, that's the first thing I would say. And then. When they to, to use iron. I, I, I am a food first person. I just, we can't do everything with food anymore. I wish we, I'm the first person to who wishes we could get everything we need from food. But I, I no longer believe that's the case. Uh, and uh, obviously when once iron levels are really deficient.

Libby Weaver: We, we need to be very careful for someone who has celiac disease or is abstaining from gluten. We need to make sure those iron levels are actually improving because for so many of them, uh, they've lived with low iron for such a long time. And, uh, so I say to people, if you find out you are iron deficient and, and also have celiac or decide to go gluten-free, whatever changes you make, whether it be to what you are eating or your supplementation, you wanna retest your blood.

Libby Weaver: In three months to make sure what you are doing is actually working. What you don't want to do is [00:33:00] think, oh, well now I don't eat gluten, or now I've been diagnosed with celiac disease, my iron will just naturally come. Right? It may or it may not, so, but you, you could live for another couple of years with lousy iron status.

Libby Weaver: If you don't actually go and find out, you need to know that your gut is healing and that your iron status is actually improving. So I think a, a blood test after about three, three months after diagnosis is important. And then sometimes four blood tests in that year is actually, I think, key to actually seeing if the person's iron status is actually responding.

Jodi Duval: Hmm, absolutely. I think a, again, you make a really good point in that there is so much else that we don't know in relation to our immune system and what is the chicken and egg? You know, they may already be iron deficient and therefore immune system, you know, is low. There is a deficiency in the immune system and therefore.

Jodi Duval: You know, autoimmune is on the rise, or we all know it. It's just in incredible how quickly it has, um, accelerated in our life. And we know that it's a, it's a [00:34:00] combination of so many different things. You know, we can talk about the chemicals or preservatives, we can talk about EMF, we can environmental, mold, et cetera, et cetera.

Jodi Duval: We can go on forever. Again, another, another time conversation. But when we're looking at Celia, I think, again, there could be so many different triggers that we don't know. Yeah, and the, there is ways that I, I look at some sensitivities and we can do intolerances, food testing, but it's not, again, like they shift.

Jodi Duval: So an already, um, reduced immune function or a hyperactive immune system, it's going to be firing on all cylinders at everything. So you, you will change and shift accordingly. So yeah, it's, it's really. Again, it's, it's, I think the guidance of the right support and like you said, the constant check in. Yeah.

Jodi Duval: It's incredible to, to keep doing that. So I think it's, it's hard for people to hear this. Yeah. 

Libby Weaver: And it's super, it's actually, so the mucosal immune system, if people can imagine your mu, your mucosal immune system lines all of the surfaces. Where there are orifices that are essentially exposed to the outside world, and so it's, you know, in your nasal [00:35:00] passages, it's in your, it's in your digestive system.

Libby Weaver: So that mucosal immune system actually has a really strong relationship with great iron status. So it is far more robust when we have good iron status. It is, its function is depleted when we are iron depleted. So. Those two there, there's very good research looking at that. So particularly for the gut that our good iron status is just so crucial.

Jodi Duval: Yeah, I, I really like some of the microbiome studies that are coming out, uh, with the, with iron as, as a big focus point as well, which is so interesting. And it, it's, you sort of go, oh, well of course, you know, the gut has everything to do with everything, but then you don't realize until the research actually comes out and you're like, boo.

Libby Weaver: There it is. 

Jodi Duval: Yeah. I should have known that. Yeah, of course. Um, okay. Brilliant, brilliant. Let's talk a little bit more about specificity, and I know you've mentioned like ideal iron supplements, but sort of what are you seeing across the board of people being given you? Ferran c you know, you've mentioned that there's a ferritin.[00:36:00] 

Jodi Duval: What if they can't get that? What are, what are best ways to, um, support in terms of supplementation and what's the best thing not to be doing? Maybe that's, maybe just clear that up a little bit before we move on. 

Libby Weaver: Yeah. So the really, so the research, if you're gonna use a sim, so the ferritin iron that I talked about, it's from organic pea, so it's actually from food.

Libby Weaver: Uh, so the bioavailability is exceptional. So if you can get your hands on that, it is. By far, um, the, by far the best that we have. So, but if you're taking a synthetic iron supplement, it needs to be less than 24 milligrams per dose. Uh, and if you are using a synthetic one, it needs to be every second day.

Libby Weaver: The research shows. Fairly consistently. There is a little bit of conjecture that there was not a big significant difference between daily and every second day. Um, but at the moment the research still leans towards every second day supplementation. And as you mentioned, Jody, um, morning absorption is better than afternoon 'cause hepcidin is.

Libby Weaver: Naturally lower in the morning. So [00:37:00] what I would encourage people to avoid though, are those high dose synthetic supplements that cost about $2, uh, at a, you know, at a discount pharmacy. So, because they are. There's huge amounts of iron in them that is just gonna become free iron in your gut cells. I worry that that damages the gut.

Libby Weaver: I worry that it does create gut related symptoms for too many women, so then they're not gonna keep taking it anyway. So then they'll just live with iron deficiency because they'll, I worry that people try those hideously high dose. Super cheap synthetic supplements and think, oh, I tried that, it didn't work.

Libby Weaver: Or, I tried that and it upset my tummy, so I'm just gonna have to live with iron deficiency. No, no, no. You want to find a, a, a food way, a food forward way, a an iron supplement that actually supports you and that you actually get results from. So yeah, the no, no. Are those high. Uh, synthetic ones, essentially.

Jodi Duval: Okay. I think I need to drop, um, your book at every single doctor's [00:38:00] office around the world, because I feel like I'm banging my head up against the wall most of the time. Like, I, I still don't understand. Uh, I, I get on my horse about this a lot. I still don't understand why, um, gps front facing, and I get it.

Jodi Duval: It is acute care. It's acute medicine, but they're the ones generally they get the first time. You know, blood results and then they make the recommendations. Even pregnant women, uh, you know, or, or prenatally trying to prepare and they get on the iron as a, as a prevention and it's, it's always the wrong iron and, and so.

Jodi Duval: I know as an education missing piece, you know, there's still that original education that's there, but surely there's some research that they can stay up to date with. Like what, what's your perspective on this? 'cause it frustrates the hell outta me. 

Libby Weaver: Well, I wrote the book mostly for, for consumers and just so women are better armed.

Libby Weaver: But I hear, I take your point. It's, um, I, I need to deliver it to practices. They, they're very busy. They have a lot on their plates. Um, they, they, yeah, they, I guess they [00:39:00] don't create this. Space to stay up to date on a lot of them, on iron, on research, it's not really, I think too, we expect a lot from our gps that isn't always their training.

Libby Weaver: Um, and we probably need to diversify sort of what we expect to get. They're not trained in nutrition, you know, it's a two hours or something. So it's, uh, it's finding, getting nutrition information probably from other places. Yes, we need bloods. Our blood work done through our gp, although you can request them privately as well these days, which is great, but you do need someone who will interpret the results for you.

Libby Weaver: Uh, but in saying that. Another big worry, Jody, is not just the lousy quality supplements that are potentially being recommended through GPS offices, but it's also the way blood tests are interpreted. So when people have iron studies tested, it's four different tests as you will be familiar with. So we test serum iron, which is more a reflection of.

Libby Weaver: What you've just eaten or supplementation. There's transferrin, which is actually elevated in [00:40:00] iron deficiency and iron deficiency anemia. So transferrin is again like a taxi that drives iron around, so the body will create more taxis in an attempt to get more passengers. The passengers obviously being the iron.

Libby Weaver: So I think people can get confused when they have iron studies tests done. Because they'll, they might see transferrin is high and they think, oh, that's related to iron. I must have too much iron. But no, no. Transferrin is not iron. It's, it's a, it's a transporter. It's a taxi for iron. So the normal range in Australian and New Zealand pathology labs for adult women for transferrin is two to 3.6 grams per liter.

Libby Weaver: But I like to look at optimum amounts. And in my experience, once transferrin goes above about 2.6, so that's still inside the normal range, it's a sign that the body is seeking more iron. So you don't necessarily, depending on other parameters in these iron studies, it doesn't necessarily mean you need to supplement, but it means it's encouraging you to focus on getting enough iron from wherever your food or a supplement, whatever [00:41:00] the case.

Libby Weaver: So above 2.6, you can sort of see it as a sign of iron hunger if you like. Mm. And certainly once it's out of the normal range, elevated, it's, it's, you know, the body's saying, give it to me. Now, the other, uh, in the Iron Studies, blood tests, it will also measure sat transfer and saturation. So that's how many passengers are in the taxi.

Libby Weaver: Uh, and then of course, ferritin and the normal and ferritin is your iron storage. So the normal range for adult women. In Australia and New Zealand right now is 20 to 220 micrograms per liter, which is a crazy, large, normal range. And we need to have normal ranges 'cause it would be chaos without them. But in my experience, that lower end of the normal range is way too low.

Libby Weaver: So as I said earlier, think of ferritin in your body, your ferritin that we do a blood test for. Think of that. Like your backup battery, and there's literature to support this, but it's certainly my clinical experience that once ferritin is below 50, a lot of women feel really flat and there's just not enough there [00:42:00] in the backup tank, particularly if they're having heavy bleeds.

Libby Weaver: Uh, so I like ferritin to the optimum range of ferritin, I think is between 50 and 150, but certainly for women, if you are, let's say your, you get a blood test back and your ferritin is 22, and you'll be told it's normal. 'cause it is in the normal range, but most women don't feel great when their ferritin is that low.

Jodi Duval: Hmm. Yeah, absolutely. Libby, you so translatable the way that you explain things and I, I, I, I. Really, really appreciate it from a point of view is it's really hard to explain this in a easy, understandable way, and it's just so translatable the way that you do this, and I think it just makes it so much easier for people to understand to, to make action, to speak about it.

Jodi Duval: So thank you because I just listening to you talk about all of this. It's just, you know, the knowledge. You, you have such an incredible knowledge, but you're able to, to say in ways that need to be translated to everyone, and even those who I know about biochemistry sometimes, we don't get exposed to this all the time.[00:43:00] 

Libby Weaver: Thank you. That's really kind. I hope to, I, I try to do that act when I was doing my PhD. At the end of every year, you have to present all your data and so it's to this geeky room of. The whole faculty. And so I did that, and at the end of it, one of my professors said, I want you to do that now, like you're on the six o'clock news.

Libby Weaver: In other words, present it so that an ordinary person who's not a scientist could explain it. And it was so confronting, but I, I was in front of a whole room of people and so I had to do it. And I thank him for putting me on the spotlight. Now because it also made me realize so much gets wasted if we can't say it in a way that everyone can understand, and that makes this kind of stuff accessible.

Libby Weaver: So yeah, that was, that was a confronting little moment, but one that taught me a lot. So I really appreciate you saying that, Jody. Thank you. 

Jodi Duval: Yeah, no, just such beautiful clarity and you have. Um, you have news voice, which is good. Like, swear you, you've been on channel nine before. I'm sure you have. [00:44:00] 

Libby Weaver: Well, I've, I, I love doing these, I love having these long form chats and yeah, your questions are amazing, so thank you.

Jodi Duval: Oh, that's awesome. So now I, I wanted to check in with, so firstly, before we sort of wrap this up, 'cause I'm, I'm aware of timing, but, and I wanna make sure that everyone knows where to find you, your books and all your information. But what I wanna cover off first is performance and iron, because I've. I see a lot of high performers, um, and women, particularly in the sports.

Jodi Duval: I'm really advocate of women in sports because it doesn't get enough attention as it deserves. But what I notice obviously is iron is a big problem with men too, actually in sport. So comments around that. What have you found? What, what do you recommend? What do you see? 

Libby Weaver: Yeah, so again, a really another group who often don't know about the importance of iron.

Libby Weaver: They can be low in iron and not, not know that it obviously affects performance, particularly because of it. Uh, iron's role [00:45:00] in the oxygenation of. Tissues. Uh, so, but also too, when you think about what you are asking your heart to do when you exercise, the, the heart obviously is pumping blood. And that blood contains, uh, those red blood cells that have gotta deliver the oxygen to every little cell inside you.

Libby Weaver: So, um, when we get short of breath. Sooner than we otherwise would. And you think that doesn't really match with the, with my fitness and the way that I'm training. You want that to be a red flag of I need to get my iron tested. Or if you notice that your recovery starts to become compromised, um, be, don't just think, oh, it's, I think a lot of people think eight, they write so much off to age.

Libby Weaver: I've even had 25 year olds say to me. 'cause I'm 25 now, you know? But it's not, it's just feedback that something needs tweaking. So, uh, when your recovery starts to become poor, for example. But yeah, so with any kind, people sometimes don't think of themselves as athletes, but they train like they are athletes.

Libby Weaver: So even if you [00:46:00] don't connect with that word, if fitness is very important to you and you train a lot, the research is very clear that. Uh, iron requirements can be up to 1.7 times the RDI, depending on your level of training, not so much with weight training. It's not really shown to have a big impact on iron status.

Libby Weaver: Uh, but the, the endurance, endurance runners especially. Uh, they're the ones that need to be especially mindful. There was a study done on female rowers, uh, and the level of iron deficiency anemia in female rowers was really significant. And yeah, the, the impact on their health, uh, how often think about sickness too.

Libby Weaver: Obviously it. We can't train when we're sick. Uh, so it can disrupt, you know, training, preparation for an event or a competition. So yeah, it's, it's def it's, it's a big one to watch out for. Uh, I think, and athletes are usually really focused on protein and as I said earlier, kind of jokingly, creatine's having its moments.

Libby Weaver: So lots of people are very focused on that right now, [00:47:00] and iron is just getting missed, uh, in, in so many populations, but including our athletes. 

Jodi Duval: Yeah. Yeah. They're, they're a tricky demographic to work with. I like the challenge, but they definitely are stuck in their ways and their belief systems. Yeah, they're fun.

Jodi Duval: They're fun to break through. 

Libby Weaver: They're lucky to have you though. Just, you know, dropping little threads of goodness or insight or prompting them to reconsider some things. They're lucky to have you, Jody. 

Jodi Duval: Oh, thank you. I had a funny one actually, before coming on here. I had a client before who I know from years ago I saw her and she is, um, I'm women triathlon, so she loves, uh, intensity sport.

Jodi Duval: She's now got two young kids under two. So now she's gone in different intensity sport. And I said to her today, I was like, oh, so what have we got coming up? And she's like, oh, I've got a. I've got a half iron man coming up. I'm like, I knew it. I knew it. And she's like, no more after this. And then I said, oh, okay.

Jodi Duval: You know, there's, oh, it's really cool. Like, you just wanna do running? Yeah. Don't you? So, so many. Cool. Like 100 k, like massive runs. She's like, [00:48:00] yes, that would be amazing. I'm like, got you, got you. They're gonna do something after this. She's like. 

Libby Weaver: And obviously having had two children, you know, and given that, you know, created a whole new blood supply for two new humans and that training that is, you know, he person to watch iron levels in.

Libby Weaver: Absolutely. Absolutely. 

Jodi Duval: I know. So I'm interested to see what her testing, uh, says when it comes back. So, yeah, it's just so funny. I love working with clients. I just, they light up our lives, so it's so good. Um, alright, so Dr. Libby, tell us where we can find you, where your. What your books, where we can find your books, online websites, Instagram, all of that stuff.

Libby Weaver: Oh, thank you, Jody. So my website is dr libby.com, so dr libby.com. Uh, my books are there. They're in, some of my books are in bookshops, but yeah, they're all on my website as well. Fix sign first. The one thing that changes everything is my latest book, and then I also have a supplement company that's all made from food, and it's called Bio Blends.

Libby Weaver: And we're our, the [00:49:00] Instagram is this Dr. Libby, and also bio blends, so people can have a look there. 

Jodi Duval: Incredible. Well, thank you again so much for your time, expertise, and having this fun iron conversation with me. 

Libby Weaver: Oh, thank you for caring so much, Jody. It's just been delightful to chat. Thank you. 

Jodi Duval: My pleasure.

Jodi Duval: All right. I'll see you soon.