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Jen: Welcome to the So That's
Why podcast, where we unpack the

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science behind everyday questions.

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I'm Jen.

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Matt: I'm Chris.

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And I'm Matt.

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Jen: Okay.

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A quick one to kick us off.

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What is the most common nutritional
deficiency on the planet?

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Matt: B12.

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Chris: Vitamin D.

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Jen: Okay.

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It's not B12 or vitamin
D. It's actually iron.

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Around a quarter of the world is
anemic, and roughly half of those

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cases come down to one mineral
that most of us barely think about.

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Um, so today we are gonna talk
about why do we need iron and why

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are so many of us running short?

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Matt: Yeah, a quarter of the
world, and yet iron isn't the one

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trending on TikTok at the moment.

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Magnesium is currently the
one getting all the spotlight.

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Vitamin D obviously gets the headlines,
and iron's just sort of quietly out

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the back doing all the heavy lifting.

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Chris: Which is the irony with iron.

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Matt: Yeah.

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Chris: I'm so

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sorry.

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Jen: Love the dad joke.

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Matt: The iron-y.

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Chris: In fact, I'm just gonna go.

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I'm done.

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I'll get my coat.

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Um, so iron is the reason all of
those other items we mentioned can

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function at all, the vitamin D,
the B12, w- magnesium, whatever.

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Without iron, the oxygen we're
breathing would never reach the

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s- a single cell in our body.

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Jen: So that's the bit
that always gets me.

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Every breath you have ever taken has
been delivered to your body by iron,

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and almost no one ever thinks about it.

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Matt: Yeah, so in marketing terms, I guess
iron has got a bit of an image problem.

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Jen: Yeah.

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Matt: Uh, it's got, yeah, it's
got the most important job.

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Uh, it's got no recognition.

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It sounds, I, I, it sounds
like y- every IT department I

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guess I've ever worked with.

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Jen: All the IT departments
are like, "Yes."

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Matt: Yes.

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Jen: Finally.

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Matt: That's my suppli- that's my mineral.

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Right.

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Gr.

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Well, sh-

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Chris: we got a shout-out.

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IT finally got a shout-out on the show.

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So

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Jen: back to iron.

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Chris: Yeah, so hopefully by the end
of this episode, if we actually do

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our job, you'll know exactly why, um,
low iron makes you tired in a way that

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no amount of coffee will fix, and why
some people need significantly more

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than others without ever realizing it.

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Jen: So it's always helpful, isn't it, to
put, like, the scale of this into context.

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So the World Health Organization,
they estimate that around 25% of

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the global population is anemic.

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So that's roughly two billion people.

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Um, and iron deficiency is responsible
for about half of those cases of anemia.

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Chris: It's massive, isn't

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it?

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Matt: It's huge.

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Yeah, two billion people.

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I mean, that's an
enormous number of people.

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Oh, it is something that most
of us barely think about.

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I don't even know how
you define two billion.

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I know.

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Do you know what I mean?

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I can't imagine the number in my head.

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Jen: I know.

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Chris: Yeah.

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It tends to, uh, creep in gradually
when it comes to iron, so most

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people don't notice that they've
been running on reduced capacity

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for months, sometimes even years.

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Jen: So where it gets really
interesting clinically is a category

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called iron deficiency non-anemia.

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So your stores are depleted, you
feel rough, um, you feel tired,

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you've got brain fog, you're
slow to recover from exercise.

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I feel like maybe it's
describe- … describing myself.

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Um-

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Matt: I

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was thinking the same thing.

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I just put it down to
age, but apparently not.

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Jen: Yeah, but, you know, your hemoglobin
in these cases, it hasn't fallen far

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enough yet to trigger a clinical anemia
diagnosis on a standard blood test.

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Matt: Which is crazy, isn't it?

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So people can be properly low on
iron, feeling rubbish for it, I, I,

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I'm not talking about you, Jen, but
definitely me, uh, and the test still

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sort of tells them that they're fine.

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Jen: Mm-hmm.

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Chris: Yeah, and it's a really
important, uh, thing to distinguish here.

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So the standard test for iron
measures hemoglobin, which is

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actually the last thing to fall.

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So the true early warning sign
is ferritin, which is your iron

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storage marker, and unless your
doctor specifically asks for it,

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it often doesn't get checked.

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Jen: Okay.

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So a bit, for a bit more context, between
25 and 40% of pregnant women in the UK

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and Ireland are running low on iron.

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Um, you know, women of reproductive age,
they lose somewhere between, like, 10 and

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30 milligrams of iron per menstrual cycle.

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And those numbers that I've
mentioned, they don't even touch,

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like, athletes or plant-based eaters,
where the rates climb higher again.

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Matt: Yeah, which kinda makes me
wonder how many people are putting

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persistent fatigue down to just
being busy or not sleeping well,

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when there's a perfectly measurable
mineral underneath this whole thing.

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Mm.

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Chris: I suspect it's a lot of
people- Yeah … to be fair.

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And, um, of course, fatigue is arguably
the most reported symptom of low iron,

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and it's the easiest to miss because
everybody has it some days, don't we?

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You know, we all have days
when we, we feel tired.

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Um, but the pattern people miss is
when it doesn't seem to improve, so

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no amount of sleep seems to restore
you or it feels like the caffeine

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stops doing what it used to do.

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Jen: Okay.

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So what's actually… what is
iron actually doing in the body?

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That's what people probably wanna know.

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So about 70% of all the iron in your body
is locked in two proteins, hemoglobin

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in your red blood cells and myoglobin
in your muscles, and both have one

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job, and that is moving oxygen around.

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Chris: That's right.

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And hemoglobin, or he- each hemoglobin
molecule carries four iron atoms kinda

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tucked inside it, and then each one grabs
a single oxygen molecule in the lungs,

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holds onto it through the journey, and it
lets it go where it's needed in the body.

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So if you multiply that across the
trillions of red blood cells in your body,

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you've got this kind of oxygen, I guess,
like, courier service running constantly

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in every direction, never stopping.

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Matt: Yeah.

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So I, I guess iron's basically the
postmaster in the postal system, isn't it?

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Without it, the oxygen never gets
sorted, never gets delivered, and

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never makes it to the front door.

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Chris: We could call it Iron Man,
but I, I guess that's already gone.

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Someone beat

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Matt: us to the punch.

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Yeah.

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I like that.

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This is the Iron Man episode-
Yeah … uh, for the purposes

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of search engine optimization.

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Brilliant.

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Jen: Okay.

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So when your iron levels drop, um, the
system, your body, it doesn't stop.

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Obviously, it just slows down.

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So your red blood cells get made smaller
'cause they've got less hemoglobin packed

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in, so then each one carries less oxygen.

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So your body is still delivering,
it's just sending half-empty parcels.

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Chris: Yeah.

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That's right.

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And, and that's what causes the
kind of symptoms to cascade.

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So less oxygen reaching the brain
means poorer focus and slower thinking.

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Less reaching the muscles means, uh,
breathlessness and fatigue, and less

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reaching the immune cells means a, a kind
of, a slower recovery from any infection.

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Jen: Mm.

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Matt: Yeah.

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Which would explain why low iron
symptoms feel so scattergun, don't they?

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You've got the brittle nails, the
brain fog, the racing heart all at

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once, and it's, I think it's easy
to put that kind of thing down to

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different things when it's actually
one mineral underneath all of it.

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Jen: It is.

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And you mentioned brain fog, Matt.

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Uh, so that actually does deserve its own
moment because the research is striking.

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There was a 2023 systemic review
of 13 randomized controlled trials.

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So they found that giving school-age kids
iron supplements significantly improved

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their intelligence because it impacted
attention, concentration, and memory.

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So there was measurable cognitive gains
from correcting just one nutrient.

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Chris: That's it.

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And we see the same, um,
pattern in brain scans.

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So areas of the brain involved
in reasoning and problem-solving,

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they massively depend on iron.

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So when these iron levels are
low, the performance drops.

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Matt: Yeah, and that's the story
from the body side of it, isn't it?

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But when we zoom out to diet, it gets a…
it seems to get a lot more complicated.

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Iron doesn't all come in the same form.

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There are two types, aren't there?

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There's heme, there's non-heme iron, and
that difference really matters, especially

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if you're on a plant-based diet.

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So can you guys explain
that a little more?

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Chris: Sure.

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So heme iron comes from animal
sources, so things like, uh,

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meat or fish and shellfish.

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And heme iron's absorbed at roughly 15 to
35% kind of absorption rate, um, almost

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regardless of what else is on your plate.

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But non-heme iron is different.

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It comes from plants, um, eggs, fortified
foods, but this absorbs much lower,

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so it could be anywhere from 2 to 20%,
and it's massively influenced by what's

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around it, so what's on your plate.

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Jen: And the, the reason for the
difference is structural, so a bit of a…

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would this fall in chemistry, biology?

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Bit of both.

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So heme iron sits inside a porphyrin ring,
and that protects it through digestion,

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whereas non-heme iron, that's got to
be converted in your gut before it can

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be absorbed, which makes it much more
vulnerable to anything that interferes.

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Matt: Yeah.

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So heme iron is more easily absorbed while
non-heme iron needs a bit more help, uh,

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depending on what else is in the meal.

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Chris: Yeah.

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That's a really good way of
putting it and a good distinction.

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And the biggest factor affecting
non-heme iron is phytates.

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So phytates are found in whole
grains, they're found in nuts, in,

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in legumes, and these phytates can
reduce iron absorption by over 50%.

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But there are other things.

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So calcium can impact it, as
well as compounds in tea and

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coffee, and some proteins.

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These things can all push
that absorption down further.

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Jen: But on the flip side, vitamin C
is like a standout enhancer, so that

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helps convert non-heme iron into a form
that your gut can absorb more easily.

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So even something as simple as,
like, a squeeze of lemon on a lentil

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dish or a glass of orange juice
with a fortified breakfast cereal

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can make a noticeable difference.

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Matt: Yeah.

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So if non-heme iron is harder for the
body to absorb, vitamin C is really what

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helps it m- helps make it more available.

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Jen: Mm.

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Chris: That's right.

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And there's a, an
interesting bit of biology.

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I think it's interesting anyway.

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Jen: Me too.

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Me too, Chris.

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Chris: Um,

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Matt: well done you two.

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Chris: We need to just go, you know.

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Yeah.

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Stick our lab coats on.

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Yeah, get on

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with it.

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Jen: Geek out in the lab.

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Chris: Um, so the body tightly
regulates non-heme iron.

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So if your b- uh, iron stores are
full, absorption naturally drops off.

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But heme iron is less tightly regulated,
which means the iron balance is

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something to think about over weeks
and months rather than a single meal.

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So it, it's not the same
depending on those two forms of

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iron that you mentioned earlier.

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Jen: Mm. And that's where
day-to-day habits start to

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matter as well, don't they?

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So tea and coffee are worth
flagging here, as Chris said.

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Um, so the polyphenols and the
tannins, they bind to iron and

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reduce how much is absorbed.

241
00:11:10,440 --> 00:11:15,380
Even a cup within an hour of an iron-rich
meal can noticeably reduce its uptake.

242
00:11:15,380 --> 00:11:17,770
Matt: Yeah, which is…
immediately complicates life

243
00:11:17,770 --> 00:11:18,800
if you're British, doesn't it?

244
00:11:18,800 --> 00:11:22,720
Because the post-meal cup of tea is,
well, it's a national institution.

245
00:11:22,720 --> 00:11:23,870
It is in our house anyway.

246
00:11:23,870 --> 00:11:24,890
Jen: Yeah, absolutely.

247
00:11:25,120 --> 00:11:26,000
Chris: Yeah, don't fear, Brits.

248
00:11:26,240 --> 00:11:28,820
It's not too catastrophic,
so there's plenty of room to

249
00:11:28,820 --> 00:11:30,210
enjoy your, uh, cup of tea.

250
00:11:30,270 --> 00:11:30,480
Jen: Yay.

251
00:11:31,260 --> 00:11:33,560
Chris: It's just a case
of considering the timing.

252
00:11:33,560 --> 00:11:38,620
So, um, it's ideally just don't have
it in the same hour as a meal that's

253
00:11:38,620 --> 00:11:39,700
meant to be topping up your iron.

254
00:11:39,700 --> 00:11:44,150
So give the iron time to absorb and then
enjoy that lovely cup of British sh- tea.

255
00:11:46,160 --> 00:11:49,080
Jen: Well, it's worth us talking
about who needs to pay particular,

256
00:11:49,140 --> 00:11:52,990
um, attention here 'cause the
variation between groups is huge.

257
00:11:52,990 --> 00:11:56,860
So adult men, for example, under
the age of 50 need around about

258
00:11:56,930 --> 00:11:58,700
eight milligrams of iron a day.

259
00:11:59,000 --> 00:12:03,280
but then women of reproductive
age need about 18 milligrams a

260
00:12:03,280 --> 00:12:07,240
day, and then pregnant women, they
need about 27 milligrams a day.

261
00:12:07,240 --> 00:12:11,070
So we're talking about more than
a, a threefold difference depending

262
00:12:11,070 --> 00:12:12,540
on what life stage you're in.

263
00:12:13,160 --> 00:12:16,120
Matt: Yeah, and that gap I think is bigger
than I would've thought, if I'm honest.

264
00:12:16,420 --> 00:12:16,550
Jen: Mm.

265
00:12:16,590 --> 00:12:21,350
Matt: Uh, most general health advice gets
pitched in the, at the average, isn't it?

266
00:12:21,350 --> 00:12:21,630
Jen: Yeah.

267
00:12:21,630 --> 00:12:25,180
Matt: Um, but iron really feels like
one of those nutrients where average

268
00:12:25,460 --> 00:12:27,160
perhaps doesn't really mean that much.

269
00:12:27,270 --> 00:12:27,480
Jen: Mm.

270
00:12:27,670 --> 00:12:28,220
Chris: No, that's it.

271
00:12:28,220 --> 00:12:30,630
And the, the… You're right,
the average, it just doesn't

272
00:12:30,630 --> 00:12:31,910
cover those different groups.

273
00:12:32,310 --> 00:12:37,380
Um, and I'd say pregnancy, well, without
a doubt, is the most demanding window.

274
00:12:37,380 --> 00:12:41,760
So the total iron requirement across
the entire pregnancy is about one gram.

275
00:12:41,890 --> 00:12:47,390
Um, so that's roughly 360 milligrams
goes to the baby, mostly in the third

276
00:12:47,450 --> 00:12:52,680
trimester, and about 450 milligrams is
used to expand the mother's blood volume.

277
00:12:52,930 --> 00:12:57,290
And in fact, did you know, fact fans,
that the mum's blood volume increases

278
00:12:57,290 --> 00:12:59,860
by about 30% to 50% during pregnancy?

279
00:12:59,860 --> 00:13:00,520
Jen: Wow.

280
00:13:00,520 --> 00:13:00,540
Matt: Wow.

281
00:13:00,540 --> 00:13:00,710
That's a

282
00:13:00,710 --> 00:13:01,306
Jen: lot, isn't it?

283
00:13:01,306 --> 00:13:01,840
Matt: That is a lot.

284
00:13:01,850 --> 00:13:02,770
I wouldn't have guessed that.

285
00:13:03,270 --> 00:13:06,620
And so with the added need, it's
fair to say pregnant ladies don't

286
00:13:06,630 --> 00:13:09,570
usually get enough iron then, I'm
guessing, solely from their diet.

287
00:13:09,660 --> 00:13:09,760
Mm.

288
00:13:09,870 --> 00:13:10,140
Chris: No.

289
00:13:10,190 --> 00:13:10,670
That's right.

290
00:13:10,670 --> 00:13:15,360
So the typical diet provides about 15
milligrams of iron per day, and we're

291
00:13:15,360 --> 00:13:18,400
talking about a requirement, as Jen
said, of about 27 milligrams per day.

292
00:13:18,400 --> 00:13:23,820
So that's why routine supplementation
in prenatal vitamins is recommended

293
00:13:23,820 --> 00:13:25,410
a- and absolutely essential.

294
00:13:25,870 --> 00:13:29,900
Jen: And just to build on that, a baby
actually starts building up iron stores

295
00:13:29,930 --> 00:13:34,770
in those, the final three months of the
pregnancy, which then sustains them for

296
00:13:34,770 --> 00:13:36,610
the first four to six months of life.

297
00:13:36,840 --> 00:13:40,980
So in a very real sense, the foundation
for early infant development is

298
00:13:40,980 --> 00:13:43,110
being laid down even before birth.

299
00:13:44,120 --> 00:13:47,030
Matt: That's a properly impressive
bit of biology, isn't it?

300
00:13:47,040 --> 00:13:50,470
Mm. Um, when you think about
it, all that buffering before

301
00:13:50,470 --> 00:13:52,010
the baby's even been born.

302
00:13:52,640 --> 00:13:53,830
Chris: It really is a
bit, let's be honest.

303
00:13:53,830 --> 00:13:54,800
It, it blows your mind, doesn't it?

304
00:13:54,800 --> 00:13:55,410
Jen: Yeah.

305
00:13:55,410 --> 00:13:55,470
Matt: Yeah.

306
00:13:55,470 --> 00:13:56,290
In so many ways.

307
00:13:56,290 --> 00:13:57,420
Chris: The amazing…
The amazing thing about

308
00:13:57,420 --> 00:13:57,440
Matt: it.

309
00:13:57,460 --> 00:13:59,430
Now, that bit of biology
I found interesting.

310
00:14:00,450 --> 00:14:00,640
Chris: Just

311
00:14:00,640 --> 00:14:00,760
that

312
00:14:00,760 --> 00:14:00,880
one.

313
00:14:00,880 --> 00:14:01,240
Jen: We're converting him.

314
00:14:01,240 --> 00:14:01,360
Matt: Just,

315
00:14:01,360 --> 00:14:01,720
just that one.

316
00:14:01,720 --> 00:14:02,200
Jen: We're converting him slowly.

317
00:14:02,200 --> 00:14:02,680
Just that one bit.

318
00:14:02,680 --> 00:14:03,040
Chris: That one bit.

319
00:14:03,040 --> 00:14:03,070
Jen: That

320
00:14:04,830 --> 00:14:05,410
one piece.

321
00:14:05,790 --> 00:14:05,810
Chris: Yeah.

322
00:14:07,870 --> 00:14:11,960
Uh, so moving around, so athletes are
another group, um, worth highlighting

323
00:14:11,960 --> 00:14:15,080
here when it comes to iron, and it's
particularly female athletes actually.

324
00:14:15,080 --> 00:14:20,950
So they lose iron through sweat,
through impact-related, uh, bled r-

325
00:14:21,030 --> 00:14:23,880
uh, red… I think I said bled rud, so.

326
00:14:24,150 --> 00:14:24,430
Yeah.

327
00:14:24,490 --> 00:14:25,480
I mean red blood cell.

328
00:14:25,480 --> 00:14:25,490
You

329
00:14:25,490 --> 00:14:25,520
Jen: were, you were

330
00:14:25,520 --> 00:14:25,540
Chris: on

331
00:14:25,540 --> 00:14:26,300
Jen: the right line, weren't you?

332
00:14:26,300 --> 00:14:30,480
Chris: Um, so red blood cell damage
in the feet during running, for

333
00:14:30,480 --> 00:14:34,300
example, and through low-level
gastrointestinal micro-bleeding from

334
00:14:34,300 --> 00:14:35,590
sustained training, which I know-

335
00:14:35,830 --> 00:14:36,420
Jen: That sounds horrendous.

336
00:14:37,130 --> 00:14:38,540
Chris: It does, but you know, look it up.

337
00:14:38,580 --> 00:14:41,140
It, it's surprisingly
common and pretty painful.

338
00:14:41,960 --> 00:14:46,330
Um, and that's where iron deficiency
without anemia becomes a real performance

339
00:14:46,330 --> 00:14:47,660
issue with those kind of factors.

340
00:14:47,690 --> 00:14:47,700
Mm.

341
00:14:48,936 --> 00:14:52,516
Jen: And so we've mentioned it briefly,
but then we get to, like, plant-based

342
00:14:52,516 --> 00:14:54,966
diets, and they change the picture a bit.

343
00:14:54,996 --> 00:14:59,246
And this is where things get really
practical because non-heme absi-

344
00:14:59,246 --> 00:15:01,426
iron absorbs less efficiently.

345
00:15:01,436 --> 00:15:05,106
Um, so ve- vegans and vegetarians,
they need to consume about

346
00:15:05,176 --> 00:15:09,926
80% more iron to meet the same
requirements as someone eating meat.

347
00:15:10,246 --> 00:15:13,436
So then a vegan woman of
reproductive age isn't aiming

348
00:15:13,456 --> 00:15:15,356
for, like, 18 milligrams a day.

349
00:15:15,356 --> 00:15:18,076
She's more, like, aiming
for 32 milligrams a day.

350
00:15:18,536 --> 00:15:20,196
Matt: Which is a meaningful jump.

351
00:15:20,296 --> 00:15:20,596
Jen: Mm.

352
00:15:20,676 --> 00:15:25,066
Matt: Um, and I suppose the real question
is whether people actually adjust for

353
00:15:25,066 --> 00:15:29,946
that in practice, or is it something maybe
that gets missed in the day-to-day eating?

354
00:15:29,956 --> 00:15:29,966
Mm.

355
00:15:30,176 --> 00:15:30,416
Chris: Yeah.

356
00:15:30,416 --> 00:15:33,036
So data tells us that it
does get missed very often.

357
00:15:33,036 --> 00:15:39,016
So studies on v- uh, vegetarian and vegan
iron status show high rates of depleted

358
00:15:39,016 --> 00:15:42,446
iron stores compared to omnivores,
which is, I guess, no real surprise.

359
00:15:42,836 --> 00:15:46,296
But importantly, not higher rates of
clinical anemia, believe it or not.

360
00:15:46,436 --> 00:15:46,686
Matt: Mm.

361
00:15:46,726 --> 00:15:49,606
Chris: So what you tend to see
is the body compensating, so it's

362
00:15:49,626 --> 00:15:51,516
working harder to maintain levels.

363
00:15:51,806 --> 00:15:58,136
But this does require a bit of awareness,
and the main message is iron levels are

364
00:15:58,136 --> 00:16:00,166
very simple to control regardless of diet.

365
00:16:00,646 --> 00:16:04,536
But you do need to give some consideration
to the actual iron intake and all

366
00:16:04,536 --> 00:16:07,046
those factors that affect absorption.

367
00:16:07,896 --> 00:16:12,896
Jen: And then just to widen the lens
a bit, children between, um, six to…

368
00:16:12,896 --> 00:16:16,176
Six months and two years, they're
another group where iron really matters.

369
00:16:16,176 --> 00:16:19,426
So growth is rapid,
isn't it, in that period.

370
00:16:19,436 --> 00:16:24,166
Mm. Um, breast milk is naturally low
in iron, and that's a window where

371
00:16:24,186 --> 00:16:28,486
deficiency in infancy has been linked
to longer term cognitive effects.

372
00:16:28,486 --> 00:16:33,466
So it's worth being quite deliberate about
iron-containing foods at that stage too.

373
00:16:33,666 --> 00:16:33,996
Matt: Yeah.

374
00:16:33,996 --> 00:16:37,956
So if someone's listening and wondering
whether, you know, they should

375
00:16:38,016 --> 00:16:41,326
actually do something about their
iron, maybe you're listening, maybe

376
00:16:41,326 --> 00:16:42,316
that's the question you've got now.

377
00:16:42,376 --> 00:16:44,366
Mm. Where's the best place to start?

378
00:16:44,796 --> 00:16:45,086
Jen: Okay.

379
00:16:45,086 --> 00:16:49,126
So the best starting point is a
blood test, but not just any blood

380
00:16:49,126 --> 00:16:52,896
test, a blood test that includes
ferritin, not just hemoglobin.

381
00:16:52,896 --> 00:16:57,546
So that's the most useful single
marker, um, because it tells you

382
00:16:57,546 --> 00:17:01,106
whether your stores are actually
depleted, not just whether you've

383
00:17:01,116 --> 00:17:02,586
crossed the line into anemia.

384
00:17:03,146 --> 00:17:03,346
Chris: Yeah.

385
00:17:03,346 --> 00:17:07,626
And from a food perspective, um, the
highest density plant sources of iron

386
00:17:07,626 --> 00:17:14,314
are cooked spinach, uh, lentils, tofu,
uh- Soybeans, pumpkin seeds, and many

387
00:17:14,314 --> 00:17:15,824
foods are fortified with iron, of course.

388
00:17:15,834 --> 00:17:20,564
Mm. For seafood eaters, uh, oysters,
mussels, and shellfish are rich sources.

389
00:17:20,944 --> 00:17:23,944
And for meat eaters, it's fair
to say red meats are pretty well

390
00:17:23,944 --> 00:17:25,444
known as, as being high in iron.

391
00:17:25,674 --> 00:17:25,944
Jen: Yeah.

392
00:17:26,314 --> 00:17:26,654
Matt: Yeah.

393
00:17:26,654 --> 00:17:31,784
And also the absorption pairing we talked
about earlier, vitamin C with non-heme

394
00:17:31,814 --> 00:17:33,444
iron, I think is also quite important.

395
00:17:33,964 --> 00:17:34,594
Jen: Exactly.

396
00:17:34,594 --> 00:17:38,614
So it's the simple things like make it…
that make a difference, like a lentil soup

397
00:17:38,624 --> 00:17:43,934
with a squeeze of lemon, a spinach salad
with orange segments, um, a fortified

398
00:17:43,934 --> 00:17:48,604
cereal with like a small glass of orange
juice, and even cooking acidic dishes

399
00:17:48,604 --> 00:17:51,224
like tomato sauce in a cast iron pan.

400
00:17:51,534 --> 00:17:55,304
That can contribute because iron
leaches from the metal into the food.

401
00:17:56,324 --> 00:17:56,524
Chris: Yeah.

402
00:17:56,524 --> 00:17:58,014
And, um, back to supplements here.

403
00:17:58,014 --> 00:18:02,624
So if a supplement is, is needed,
timing's really important with iron.

404
00:18:03,034 --> 00:18:05,734
Uh, so as we mentioned earlier, it's
best to avoid things like tea and

405
00:18:05,734 --> 00:18:07,454
coffee within an hour of consuming iron.

406
00:18:07,784 --> 00:18:10,414
And actually, iron's one of the
few nutrients that it's best

407
00:18:10,414 --> 00:18:12,084
to take on an empty stomach.

408
00:18:12,634 --> 00:18:15,584
Uh, but of course, the issue in
supplements is iron's often contain,

409
00:18:15,614 --> 00:18:19,314
uh, combined with other nutrients
too, that are best taken with food.

410
00:18:19,314 --> 00:18:20,664
So it's never easy.

411
00:18:20,694 --> 00:18:22,534
There's always a bit
of a, a counterbalance.

412
00:18:22,964 --> 00:18:27,704
So I'd say as a, a general rule of
thumb, take iron in the morning because

413
00:18:27,704 --> 00:18:29,504
that's the best time for its absorption.

414
00:18:30,054 --> 00:18:32,594
Absorption tends to be highest
because of that overnight fast.

415
00:18:33,854 --> 00:18:34,164
Matt: Yeah.

416
00:18:34,164 --> 00:18:37,104
I've seen alternate day
dosing come up as well, right?

417
00:18:37,104 --> 00:18:42,094
So research suggesting it might improve
absorption, um, and reduce side effects

418
00:18:42,114 --> 00:18:44,304
compared to, uh, everyday dosing.

419
00:18:44,364 --> 00:18:45,504
Jen: Yeah, that's right.

420
00:18:45,514 --> 00:18:50,884
So daily iron triggers a hormone called
hepcidin, which down regulates absorption.

421
00:18:50,884 --> 00:18:55,654
So spacing, um, taking your iron
supplement every other day, that allows

422
00:18:55,664 --> 00:18:59,624
hepcidin to settle so absorption can
then recover ready for the next dose.

423
00:18:59,934 --> 00:19:03,304
And it's especially useful if someone
struggled with like constipation

424
00:19:03,304 --> 00:19:05,554
or stomach upsets on a daily dose.

425
00:19:06,554 --> 00:19:09,944
Chris: So one important caveat
here, and I'm sorry to do the kind

426
00:19:09,944 --> 00:19:12,964
of Captain Sensible bit, but on,
in this case- … it, it's really

427
00:19:12,964 --> 00:19:14,234
important when it comes to iron.

428
00:19:14,234 --> 00:19:21,164
So before taking a kinda high-dose iron
supplementation routine, you should

429
00:19:21,164 --> 00:19:24,184
really discuss it with a healthcare
professional first, because iron's

430
00:19:24,224 --> 00:19:28,944
one of the few nutrients where excess
really is actively harmful, and it's

431
00:19:28,964 --> 00:19:34,324
particularly with people with conditions
like hereditary hemochromatosis, where the

432
00:19:34,324 --> 00:19:36,324
gut absorbs far more iron than it should.

433
00:19:37,314 --> 00:19:38,554
Jen: Iron's so important, isn't it?

434
00:19:38,744 --> 00:19:43,384
I know we've talked in a previous episode
about magnesium driving over, like, 300

435
00:19:44,054 --> 00:19:48,194
enzymatic reactions in the body, but
iron's even more upstream than that.

436
00:19:48,204 --> 00:19:52,484
Does… It, it determines, you know,
whether oxygen gets to the cells where

437
00:19:52,554 --> 00:19:54,384
all those reactions are happening.

438
00:19:54,564 --> 00:19:58,894
So without iron, the rest of the chain
just doesn't function at full capacity.

439
00:19:59,524 --> 00:20:00,424
Chris: Yeah, you're absolutely right.

440
00:20:00,424 --> 00:20:04,494
And, and that's why iron deficiency
shows up across so many systems at once.

441
00:20:04,504 --> 00:20:09,634
So the fatigue, the brain fog, the brittle
nails you mentioned, the breathlessness,

442
00:20:10,044 --> 00:20:14,524
the slow recovery, that… All the
same underlying issues showing up in

443
00:20:14,524 --> 00:20:16,674
different tissues be- because of iron.

444
00:20:17,184 --> 00:20:21,364
Jen: And that's also why correcting
iron status when it is the cause can

445
00:20:21,624 --> 00:20:25,664
transform people's lives, 'cause he-
people often describe it as, like, the

446
00:20:25,664 --> 00:20:30,154
light's coming back on, because every
system that depends on oxygen delivery

447
00:20:30,184 --> 00:20:32,904
suddenly has the resources it needs again.

448
00:20:33,374 --> 00:20:37,194
Matt: Yeah, so the takeaway is that
not all tiredness has the same cause.

449
00:20:37,604 --> 00:20:41,104
Sleep, stress, um, and screens
obviously get a lot of attention,

450
00:20:41,104 --> 00:20:42,844
and, and you could argue rightly so.

451
00:20:43,214 --> 00:20:48,794
But sometimes the underlying piece
is biochemical, um, and it's worth,

452
00:20:48,804 --> 00:20:50,044
I think, staying open to that.

453
00:20:50,764 --> 00:20:52,844
Jen: So why do we need iron?

454
00:20:53,224 --> 00:20:58,334
Because every cell in your body depends
on oxygen, and iron is what delivers it.

455
00:20:58,764 --> 00:21:03,524
It's not the most fashionable nutrient,
but it might be the most foundational.

456
00:21:03,964 --> 00:21:10,504
Matt: Yeah, and possibly the most quietly
common deficiency on the planet, uh, doing

457
00:21:10,504 --> 00:21:14,684
one of the most important jobs in our
body, and it gets very little attention.

458
00:21:14,994 --> 00:21:19,704
Um, and I'm sure I, I will find it at
some point, uh, a metaphor for life.

459
00:21:19,704 --> 00:21:20,484
I'm sure there's one in

460
00:21:21,154 --> 00:21:21,244
Chris: there somewhere.

461
00:21:21,244 --> 00:21:21,954
I'm sure you could find one.

462
00:21:22,304 --> 00:21:23,074
Mm-hmm.

463
00:21:23,634 --> 00:21:27,244
And, uh, with iron, a key message
from us is, for most people, it's very

464
00:21:27,244 --> 00:21:28,934
manageable with a bit of consideration.

465
00:21:28,944 --> 00:21:33,284
Mm. So iron-rich foods, vitamin
C as a partner, that awareness

466
00:21:33,284 --> 00:21:37,554
around tea and coffee timing, and a
ferritin check if symptoms persist.

467
00:21:37,884 --> 00:21:39,494
They're the key things to keep a check.

468
00:21:40,464 --> 00:21:42,184
Jen: So that's it for this week.

469
00:21:42,254 --> 00:21:46,294
Hit subscribe wherever you're
listening or watching, and drop

470
00:21:46,294 --> 00:21:47,844
your question in the comments.

471
00:21:48,054 --> 00:21:49,064
We really do read them.

472
00:21:49,564 --> 00:21:52,874
Thanks for geeking out with us,
but for now, that's it from me.

473
00:21:53,184 --> 00:21:54,074
Chris: That's it from me.

474
00:21:54,374 --> 00:21:55,144
And that's it from me.

475
00:21:55,374 --> 00:21:56,054
Jen: Bye for now.