Leah:
Hello and welcome to the Ideal Nutrition Podcast. I’m Leah Higl and I’m here with my co -host Aiden Muir and today’s episode is all about common dietary deficiencies in athletes and how to avoid slash address them. This title is like mildly clickbaity and you can definitely blame Aidan for that one. He titled it. But realistically, we’re going to look at two different deficiencies overall that we will like hone in on really focus this episode on, but there are also a bunch of common nutrients that have like a suboptimal intake amongst athletes. So we’re going to take a look at those as well.
Aidan:
I was on chat GPT. I sent it a list of episodes and then I was like, what are some more that we should do? And this was one of them. was like, really? actually cool. Like there was a few hours like that’s cool idea. Let’s do that. And then on a deep think about it, it’s like, there is only like two really that like I really want to talk about. And then everything else is like suboptimal intake. yeah, let’s start with one of the two that are really common and things that we kind of care about. the first one is iron deficiency. Iron deficiency is common in general, particularly amongst menstruating women. With athletes, this becomes even more important for two reasons.
This is kind of less important reason, but one that is still relevant is that iron losses can be higher in athletes due to things like sweating, GI bleeding if relevant, and breakdown of red blood cells due to impact from things like running. It’s kind of hard to quantify how much each of those individual things matter, but I think most people can agree that iron needs are higher in athletes. The second one though, that is what I care about, because I care about performance, is that iron deficiency impacts performance. If you’re trying to be the best athlete you can be, it probably makes sense to try to avoid iron deficiency. Iron transports oxygen from the lungs to the rest of the body. It plays a role in immune function, and it also plays a role in fatigue. Obviously, you want to be optimising all of those things where possible. If you want to be the best athlete you can be.
How do we avoid iron deficiency? Going back to the title of the podcast, iron rich foods. That’s the starting point, right? There are certain people who would definitely benefit from supplementation and or iron infusions. But as a start, I think it makes sense to try and prioritize iron rich foods if you can. For omnivores, obviously red meat is the most often talked about source of iron and it’s a great source of iron.
But some of this often overlooked is that there are plenty of other sources of iron even in that kind of meat category, like fish and chicken still contain iron. They do not contain as much as red meat, but a lot of people just hyper-focus on red meat and iron and that’s about it. There are obviously a bunch of plant -based options that contain iron as well.
Leah:
Yeah, and that’s definitely my forte working with a bunch of plant-based athletes all the time. And my favourite go-tos would definitely be your fortified cereal and grain products can be great. And then from a whole food perspective, looking at soy products like tofu, texture vegetable protein, edamame, all awesome, as well as things like your legumes. Certain greens like amaranth are quite good for iron and then also some nuts and seeds. there’s quite a diverse range of foods that you can get iron from.
Aidan:
The other thing I’m big on is having some level of awareness of the recommend a daily intake for iron. Recommend daily intake is not necessarily the perfect proxy for how much iron you personally need, but I love comparing to it because we need something to compare to. If you don’t have anything to compare to, how do you know that if you increase in your iron intake by adding a certain food is actually really moving the needle? This isn’t necessarily great podcast content, but it’s an example I have to use 200 grams of red meat has around five milligrams of iron.
You could use this example of any source of course, but I’m just going to use red meat for the sake of this. grams is around 5 milligrams of iron. How do you know what that means to you until you know what the recommended daily intake is or some comparison point? For menstruating women, the recommended daily intake is 18 milligrams. 200 grams is a decent amount of red meat, so that’s 5 out of 18. For me as a male, obviously no menstrual cycle, my recommended daily intake is 8 milligrams.
That five out of my eight is huge because then I could just chuck in some plant-based sources on top of that. It’s easy, right? The higher your target is, the harder it is to hit. The example I often use is sometimes people will find out that they’re iron deficient and then they’ll add red meat once or twice per week. Maybe not even in that 200 gram amount. And six months later, they’re still iron deficient and they’re confused because they’ve increased the seeing it hasn’t solved it.
But the example I often use because I’m into running at the moment, the example I always use is it would kind of be like, say I say I want to run a marathon and I’m currently not running and I add a 5k once or twice a week. It helps. Like it helps. Is it going to get me to a marathon? Probably not. Like adding that kind of context really helps when you’re looking at addressing a deficiency.
Leah:
Yeah. And something I just wanted to note there is with the RDI for iron when you are plant-based and you are menstruating, it is 32 milligrams per day. So it’s 1.8 times the RDI if you’re plant -based. So it becomes even more complicated in that.
Aidan:
Do you have any like context on like a plant based iron amount per serve or something?
Leah:
Yeah, I always use, can’t remember off the top of my head, but a good serving of tofu. So I think 150, 160 grams of hard tofu contains about four to five milligrams of iron. So in the context of maybe potentially needing 32 milligrams, that’s not that much. So you would actually have to to get to 32 milligrams per day. You have to do a lot of very specific things and choose a lot of specific foods across the day to get anywhere near that amount.
Aidan:
I don’t even have Instagram post. Do you have a blog post on this? You know what? I don’t know if I do. I have plenty of Instagram posts on it that kind of break it down, but maybe that’s something to do. If anyone’s interested, damn Leah, she’ll send you these Instagram posts.
Leah:
Yeah, 100%. Yeah, it’s definitely something that I see a lot in practice is yeah, iron deficiency in plant-based athletes. So hit me up. The next one we’re going to chat about is vitamin D deficiency. So at a population level, this is huge. So if we look at a 2023 old analysis of research looking at almost 8 million participants, so a lot of the population found that globally, 16% of that total population were really deficient in terms of having less than 30 nanomoles per litre of vitamin D in their blood, broadening that out a little bit.
So looking at everyone who had a pretty low amount of vitamin D, so a bit more mildly deficient, that was 48% of the total population.
Aidan:
So that is at the point that we would, what is typically classified as deficient. As deficient, yeah. So based on that metric, 48% of participants in this population worldwide were classified as deficient.
Leah:
Yeah, which is half of the participants, which is crazy. It gets even more wild because if we pull everyone that had suboptimal levels but weren’t quite deficient yet, so that’s classified as around less than 75 nanomoles per litre with everyone else, so those that went from mild deficiency to extreme deficiency, that 77% of the group had less than optimal vitamin D levels or worse and were deficient or very deficient.
So 77% of the population. So you can see that at a global level, this is a really common deficiency. Then honing in on athletes specifically, it does really depend on the sport. So sports where there are lots of training sessions and games out in the sun, it does seem to be a lot more rare to have vitamin D deficiency because there is a lot of sunlight.
Obviously our body can utilise that sunlight to produce vitamin D in the body, but sports where there is a lot of time spent indoors is a very different story. And you can kind of see why vitamin D deficiency may be more common in those particular contexts. So for example, vitamin D deficiency is a pretty big concern amongst things like basketball players over like football players where most of their training sessions are going to be outside.
From a vitamin D deficiency point of view, two main ways to address this is to A, just get more sunlight. So obviously there are certain concerns around like sun exposure and skin cancer there. Living in specifically Queensland, Australia, it’s not my go-to recommendation unless you’re kind of, you know, going out in the sun at not those kind of peak UV times. But the second one is using supplements. Supplements are obviously easier to dose, easy to kind of remember for most people and then food is also an option. So you can get vitamin D through food, but supplementation overall is an easier option for most people. And particularly if you’re plant-based where a lot of our food sources are pretty minimal in vitamin D and less fortified.
From a supplementation point of view, a thousand international units is a pretty standard daily dosage. But there are many cases where we might suggest going a little bit higher than a thousand international units per day particularly if you’re rectifying an existing deficiency, I’d absolutely go higher than that for at least a time.
Aidan:
And touching on that whole like sunlight thing, like the current consensus if you live in places like Queensland is during summer, about 10 minutes of sunlight per day outside of peak hours. So not like 12 pm or whatever, like either earlier in the morning or later in the afternoon. During winter, it goes up to about 30 minutes is the recommendation. It obviously depends on your skin colour. People with darker skin need significantly more, either three times or six times depending on how dark your skin is.
Obviously when you’re looking at the six time mark, you’re like, how do I hold down a regular job like I can get this much sunlight? And obviously trying to do it outside of peak hours. Like that’s the general consensus if somebody didn’t want to supplement. I have another little bit of a story on this as well. For the first time ever, I saw somebody saying vitamin D is a scam and it is the industry trying to make money.
I am somebody who historically always tries to respond to criticisms of everything that I’ve ever done but on Twitter slash X and on threads, I’ve come to a conclusion I’m like, I hate posting on these things. Because if somebody ever like does try to start an argument on that, I hate sinking time into rebutting their argument. If it’s on Instagram, I’m like, yeah, if I put a logical well thought out responses, other people will see it and they’ll see where I’m coming from. On there, I’m like, no, somebody’s just arguing with me and I’m never going to change their mind and nobody else is going to see this.
Leah:
It’s just like arguing in the DMs with someone who has a very strong opinion.
Aidan:
Yeah. And it’s like, I don’t know, I’m trying to put out content to help as many people as I can. I want to spend time doing things that are impactful. Like I think it’s a waste, yeah, there’s somebody who’s written a big article about how vitamin D is a scam. One of the things that they said that comes from a bit of a grain of truth is that the metrics that we used earlier about how that 30 nanomole per liter is like very deficient, 50 nanomole per liter is deficient and less than 75 nanomoles suboptimal.
I like those ranges because I think we still see improvements up to about 75 nanomoles that are beyond just what we would see at that kind of 50. But if you look at random meta -analyses of the effect of vitamin D supplementation at a population level, it is often less impressive than you’d think. And some people would kind of look at this and be like, well, that doesn’t make sense. If 50% of the population is deficient and we’re just supplementing the population at random and we’re not seeing super impressive results, does this matter?
And it really depends on what you’re looking at. Something that’s very clear is the lower people are on this kind of spectrum, like if they’re very, very deficient and you address it, we see a lot of good things. Like we see improvements in bone marrow density, we see improvements in immune function, sometimes balance, sometimes strength, all of these kinds of things.
Leah:
Mental health.
Aidan:
Yeah, mental health, IBS symptoms as well. The higher up the spectrum you get, the less likely you are to see these benefits, which partly can also explain why some of these reviews don’t show that impressive result.
One thing that I found interesting is it’s like, first time I’ve ever seen anyone call it a scam, hack. Vitamin D supplements are also quite cheap as well. And it’s interesting that they were kind of making it seem like it’s a bit of a conspiracy kind of thing. And that’s so interesting, post COVID, where people on the other side of the thing would be like, the government doesn’t want you to know that vitamin D exists. I’m like, it’s a conspiracy on both sides.
Leah:
It’s very random because it’s not like the government is telling you the vitamin D either. So I don’t even know how that would work as a scam.
Aidan:
Yeah, I don’t know. A to think about. But yeah, I just, thought I’d bring it up. They’re like, interesting that like, this is also what we said before, like the carnival thing became a thing just being like, nobody’s ever out there saying that vegetables are bad. But now there is people. Anyway, let’s move on. So those are the deficiencies that we’re really looking at rectifying. But now we’re just going to look through a bunch of things that could potentially be suboptimal.
So the first one we’re going to start with is Omega 3. So just like for the general population, some people have really good omega-3 intake and other people don’t necessarily have good omega-3 intake. From an omnivore perspective, the easiest way to tell in most cases is how often people are eating fish. If people are having fish two to three times a week, particularly if they’re some form of fatty fish like salmon or sardines, usually they’re going to be getting enough omega-3.
Leah:
From a plant-based perspective, there are absolutely things that we can include in our day -to -day diet to improve Omega -3 intake. So things like your chia seeds, flax seeds, hemp, walnuts. The downside of these plant-based options for Omega-3 is they are a kind of Omega -3 called ALA. And ALA has to be converted to the more beneficial form of EPA and DHA. And that conversion rate is definitely not the best. So from an athletic perspective, I often recommend going for something like a microalgae omega-3 supplement, which is a direct source of EPA and DHA in honestly like most of my athletes, because I do think it can be beneficial for things like recovery.
Aidan:
So there are a bunch of potential benefits from this. you could have anti-inflammatory benefits, heart health benefits, joint health benefits, cognitive function. Potentially some other things like limiting muscle loss during immobilisation post-injury slash surgery. That last one, I don’t want to hype up too much. There’s just, to the best of knowledge, there’s two studies that have been done on that where they have just immobilised limbs, given some people placebo, given other people omega -3s, and we’ve seen some pretty crazy results where people have retained a lot more muscle. Do I truly believe that if we had like 10 studies on that topic that we’d see the same finding across town? I don’t actually believe that. But for right now, that’s why I use the word potentially. Like there’s always a chance. So food for thought.
A lot of these benefits outside of that one that I just mentioned, because there was only two studies, a lot of those other benefits, they are small slash inconsistent in research. That whole thing I talked about with the vitamin D, how somebody could look at the same research that I’ve looked at and come to the conclusion like, vitamin supplementation doesn’t, quote unquote, work. You could look at omega-3 research the exact same way and be like, I a meta analysis that showed that there was no difference.
But when you look at it through the perspective of being like, the benefits are often relatively small and they very likely scale based on baseline intake of omega-3 slash blood levels of omega-3 throughout, it starts to get a bit more positive. Just keep in mind that the benefits are small. For example, sometimes people will take omega -3 for joint pain, and then six months later they still have joint pain. You could come to the conclusion the omega-3 did nothing, or maybe it helped one to 3%, and you just wouldn’t know because the impact’s quite small. Many ways to look at it.
Leah:
The next one we will touch on is calcium. So the recommended daily intake for calcium is actually quite high. And athletes are probably, I mean, they’re probably more likely to reach this recommended daily intake than non -athletes just due to a potentially higher food intake overall. They have higher energy needs. Hopefully they’re eating more food and hopefully that comes with more calcium, but they are still likely, like most of the population, to kind of have a suboptimal calcium intake or it might be something that could be beneficial to have a bit more of a focus on.
It’s also not uncommon for athletes to try certain dietary approaches that result in a lower calcium intake. So a really simple one is like cutting out dairy. So if we are completely eliminating dairy, that is potentially reducing a huge source of calcium in our diet. And that’s something that we do often see amongst athletes is these kinds of dietary interventions.
Another thing would be going plant-based and also cutting out these potential sources of calcium as well, where that could be a problem. Unfortunately, we can’t test calcium levels on a blood test in that we can test them, but they actually don’t mean anything in regards to what our dietary intake is like. So our blood levels of calcium are pretty tightly controlled. So if we are lacking in dietary calcium coming in, our body will just take calcium from the bones in order to have more in the blood to keep all those important functions functioning and going. So that can lead to a thinning of the bones over time, things like osteopenia and osteoporosis. From an athletic point of view, that could put you at an increased risk of things like stress fractures.
So putting into context the calcium recommended daily intake. So RDI for people who are premenopausal women or men under 70 is a thousand milligrams per day. Putting that into food context. So 250 mLs of dairy milk has about 300 milligrams of calcium, 40 grams of cheddar cheese has around 240 milligrams of calcium, so that’s like two slices.
Something like your fish with bones can be a great source of calcium. So there is a range by John West that basically takes the bones, crushes them up and fortifies the tuna with this calcium powder. And that per tin has 800 milligrams of calcium. Which is so high.
Aidan:
Same thing with those Rokeby Farms protein smoothies. Like they’re also around 833 from memory. So like those two are just like obscenely high and like arguably maybe even a tiny bit higher than you could even really absorb in one go.
Leah:
Yeah, potentially you have to kind of have over a thousand milligrams at that point if you’re having it all in mostly one go but Obviously there are options that are super high calcium From a plant-based perspective people always point to dark leafy greens as a source of calcium on a plant -based diet from a spinach point of view 100 grams of spinach equals a hundred milligrams of calcium, so like a tenth of your recommended daily intake.
If you look at how much 100 grams of spinach is, it’s actually a lot of spinach. that’s something that is more of like a top -up source of calcium than a predominant source of calcium in my books anyway. But then you’ve got things like your fortified plant milks. So something like your VitaSoy are so good. They tend to fortify at a rate of around 120 milligrams per 100 mLs. So 200 mLs, 250 mLs might have you have between two to 300 milligrams of calcium depending on the brand.
So yeah, that’s just to give you a little context around that 1000 milligram per day recommended daily intake and how you could potentially get to that amount. So if you’re someone who is including dairy, it could be like a cup of milk with some fish with bones and some cheese on a daily basis. And that would get you there. And you could also pick some calcium up through things like your dark green vegetables, nuts, seeds and other plant -based foods as well.
Aidan:
Magnesium is another semi -common one that we’ll look at. So it’s quite common even just amongst the general public that a lot of people will fall short of the recommended daily intake. Something that I did in a previous job was do a lot of like analysis of people’s diets using some software to be like, what is their micronutrient intake looking like? And it was one of the most common things I’d see people fall significantly short of the recommended daily intake.
Hard to tell, I don’t have a strong opinion on this, but subclinical deficiency is reportedly quite common based on some research. Part of reason why I don’t have a strong opinion on this is because it seems pretty hard to test for this type of thing. So I guess I can just take the word of people who are doing this research. Because if it is quite common, then it’s like we could put this as the third one rather than the two that we’re talking about, but hard to kind of measure. And I like to be a bit more practical by talking about useful things. So instead I would just look at people’s dietary intake versus what they should be aiming for.
I talked about the recommended daily intake, but you could also make an argument that athletes have higher needs, whether it’s simply just due to things like sweating and potentially needing more magnesium juice. One of the reasons why I say this could be relevant for some people is that athletes with good diets typically should have good intakes of magnesium. Magnesium is in things like green vegetables, nuts, seeds, whole grains. If have a good intake of all of those kinds of things, you could also find a little bit in meat and a few other things. If you have a high intake of these things, you’re probably going to be fine.
It’s just as if you also have a poor diet, then you probably will have a low intake of magnesium. This could also extend to other areas of sports. Like if we’re talking about people who having heaps of like gels, like sports gels that happen to not have magnesium in them, heaps of sports drinks like Gatorade and Powerade and stuff like that, if they happen to not have a lot of magnesium, maybe you’re also more likely to fall short even if you’re doing a lot of like, quote unquote, sports nutrition as well. Why do we care about this? It’s because magnesium is involved in a lot of functions.
I see a lot of people quoting stuff like magnesium is involved in over 300 functions in the human body. So obviously having a good intake of that matters. It’s involved in things like muscle contraction, energy production, bone health, and in some cases it could potentially play a role in preventing cramps as well. Another example that I use that I think is a bit of a clear-cut example as to how this could matter to an athlete is that I think sleep is important. The research also indicates that people with higher magnesium intake typically get better sleep as well. So focusing on stuff like this, could improve sleep, could improve recovery or your ability to play your sport or whatever you do. So magnesium makes sense to stay on top of.
Leah:
Briefly touching on a kind of a less important one if you’re not plant-based, but considering the population I work with, we’re quickly touch on it, is B12. So B12, specifically for plant-based vegan athletes, is an important thing to make sure you are getting enough of. I mean, it’s not just athletes, it’s kind of everyone that is following a plant-based diet, but in practice, I find that it’s like a semi -frequent reason why my plant -based athletes are experiencing things like fatigue and poor performance is the fact that they have suboptimal B12 levels or they are deficient.
At the more dangerous end of things, I have come across things like peripheral neuropathy. So that is definitely not something you want to sustain through B12 deficiency, but it can happen if it is left there lingering for a good period of time, can damage your nerves. So B12 is really hard to get enough of on a plant-based diet because the predominant sources are typically animal-based foods. So things like meat, eggs, and dairy.
So I always recommend supplementing appropriately if you have a fully plant-based diet or even if you are significantly reducing the amount of plant-based foods you are consuming. My general recommendations are either 2 to 500 micrograms of cyanocobalamin daily or a thousand micrograms two to three times per week. That is if you already have decent levels and just want to sustain them, it could go a little bit higher if you are rectifying a deficiency.
And then you can also do things like B12 shots. There are also B12 fortified foods from a plant-based point of view. I don’t recommend relying on them just because they can be inconsistent and it can be hard to know that you are getting enough. And it’s just not something that I would mess with because of the nerve damage you can sustain with this deficiency. So yeah, if you’re plant-based, whether you’re an athlete or not, it’s something I would think about.
Aidan:
As a bit of summary, there is two main deficiencies you should really be looking at. One is iron deficiency and another one is vitamin D deficiency. The lucky thing is that these are easy to test on a blood test. You can simply get a blood test to look at these things and look at if it’s worth addressing. Other stuff that we’re considering is things like omega-3, calcium, magnesium, B12. B12 you can test on a blood test.
Omega-3, technically you can do a thing called an omega-3 index. It’s not super popular, but theoretically that is another option that can be used. You can’t just go to CGP to get that, but you can order that online or you can just assess whether you’re getting enough through food, is probably the easiest way to do it.
Calcium, same kind of concept, you can’t get a blood test for that. And then the magnesium one is a little bit hard to do. But all of these things, you can look at your diet and see how it kind of stacks up in comparison to what you should probably be aiming for. And if you are looking to optimise performance, it does make sense to have an awareness of all of these things as well.
Leah:
This has been episode 145 of the Ideal Nutrition Podcast. If you haven’t yet left a rating or review, it would be so greatly appreciated for you to do so. But otherwise, thanks for tuning in.