In this episode of the Trime podcast, we take a deep dive into the topic of calcium. You’ll learn more about the importance of calcium for health and nutrition, and how to properly optimize your intake.
We discuss various sources of calcium, the differences between natural and synthetic forms, and how minerals naturally found in algae can help improve the absorption of this essential mineral. We also explore the importance of monitoring calcium intake in relation to overall body homeostasis and how to maintain calcium balance in connection with the intake of other nutrients – such as vitamins D3, K2, and magnesium.
We also addressed specific groups like pregnant women and people with osteoporosis, for whom proper calcium supplementation is crucial. Curious how to supplement calcium appropriately to avoid excessive intake and toxicity? This podcast is for everyone who wants to go deeper and learn more about optimizing calcium intake for bone and overall health.
Podcast #43 in a Glance:
→ Main dietary sources of calcium
→ Is it possible to get enough calcium without consuming dairy products?
→ Recommended daily intakes
→ Can calcium be measured in blood? How else can I know if I get enough from my diet?
→ Calcium bioavailability and the factors that affect it – how the body absorbs calcium
→ Physical activity vs. calcium supplementation – when and how to supplement properly
→ How to get enough calcium from food – how much and what to consume
→ Osteoporosis and its relation to calcium – how proper supplementation helps
→ Protein content vs. calcium – which sources to choose to avoid overload
→ Dietary cofactors that support calcium metabolism
→ Choosing calcium sources based on target groups – pregnant women, athletes, people with osteoporosis, vegans
→ Magnesium supplementation – what it affects and how it relates to calcium
→ Risks associated with supplementation
→ What’s the best form of calcium – benefits of the natural form from algae and combination with vitamins D and K2
You can also find all subtitled podcasts on our YouTube channel.
Podcast Transcript:
[00:00:10] Michal
Continuing our mini-series on micronutrients, this time focusing on calcium. Once again, welcome Jakub Přibyl.
[00:00:18] Jakub
Hey there.
[00:00:20] Michal
Hello, good day. Thank you for tuning in again. Some people this topic directly concerns, others might not even realize they should care about calcium. Jakub, let’s begin. Calcium is a key mineral, everyone knows it—or remembers it from school, where they kept pushing milk as a calcium-rich food. What do you think about that?
[00:00:50] Jakub
Hopefully, that’s long outdated, but calcium is definitely extremely important. The question isn’t whether we get enough calcium in our diet, but how well we can actually use it. So the main topic today will be calcium-phosphate homeostasis—or more generally, calcium balance.
[00:01:14] Michal
In simple terms, how to stay in balance.
[00:01:18] Jakub
Yes, balance. How the body manages calcium.
[00:01:22] Michal
So what are the main sources of calcium? Let’s start simply – according to Wikipedia, it’s dairy products?
[00:01:53] Michal
So dairy is number one. What comes next?
[00:02:00] Jakub
It could also be vegetables, but dairy is really the primary source. Some vegetables have good calcium bioavailability, but like Brussels sprouts—people don’t eat those very often.
[00:02:50] Michal
I see, dairy leads, but that might be a problem for people with intolerance. If I cut out dairy, is it possible to get enough calcium just from diet without supplements?
[00:03:10] Jakub
Getting gram-level doses of calcium purely from food is difficult, as the recommended daily intakes are 800, 1000, even up to 1200 mg. For pregnant or breastfeeding women, it's more. Personally, I think most people could get by with less if they also have the cofactors that help maintain calcium balance.
[00:04:03] Michal
So if I don’t want to go to extremes, what’s a sensible range I should aim for?
[00:04:15] Jakub
I think around 600 to 800 mg per day. For pregnant women, it’ll be higher, but it’s important to monitor and adjust individually.
[00:04:38] Michal
Can I get my calcium levels tested in blood?
[00:04:42] Jakub
Theoretically, yes, but calcium exists in three forms in the blood, so testing only gives a basic picture. You also need to monitor kidney function and bone metabolism—it’s more complex.
[00:05:00] Michal
So it’s not as straightforward as vitamin D.
[00:05:02] Jakub
Exactly. Determining calcium levels isn’t easy, and several parameters need to be considered.
How do I know if I have a calcium deficiency or excess?
So you’d figure it out based on what I eat?
[00:05:19] Jakub
Yes, dietary habits are the best indicator. And of course, as I said, in pregnant women or menopausal individuals, calcium bioavailability can naturally increase.
[00:06:05] Michal
And what advice would you give to avoid calcium-related problems—whether too much or too little?
[00:06:17] Jakub
I’d want to know your diet and physical activity level. It’s important whether your bones are being stimulated. If you’re bedridden long-term, I’d recommend lowering your calcium intake.
[00:06:51] Jakub
For proper calcium activation, you need physical activity—like jumping rope or resistance exercises. Cycling isn’t enough because bone loading is minimal.
[00:08:19] Michal
So if I put more strain on my skeleton, can I afford more dietary mistakes, or will the body use the calcium better if I have enough?
[00:08:39] Jakub
Yes, that’s an important factor.
[00:08:42] Michal
So if my diet isn’t perfect but I’m physically active, can I let myself off the hook a bit?
[00:08:57] Jakub
Definitely. But it’s still necessary to have a minimum calcium intake—ideally from food or supplements. Supplementing with high doses can be problematic, as studies have shown that excess calcium may be linked to a higher risk of cardiovascular disease.
[00:09:44] Michal
So let’s focus on the minimum intake. How much calcium should I consume per week to avoid falling below the limit?
[00:10:01] Jakub
If we take it to the extreme, 400 mg per day would be sufficient, but I recommend sticking to 600–800 mg daily, whether from food or supplements.
[hal]
If we focus on dairy products, that’s probably the main factor to avoid exceeding the maximum intake—say, 30–40 grams of cheese per day, and then supplement it with other sources?
[00:12:55] Jakub
It depends on the form in which calcium is bound to proteins. And of course, it’s never that simple.
[00:13:02] Michal
You really enjoy diving into this, don’t you?
[00:13:04] Jakub
I do—because, for example, I use cheeses that are curdled in a way that most of the calcium is washed away during the process.
[00:13:18] Michal
What kinds of cheese are those?
[00:13:20] Jakub
Like quark. Quark has little calcium even though it's high in protein. Calcium isn’t bound to fat or dry matter, but to protein—specifically to casein micelles.
[00:13:36] Michal
So it has maybe half the amount compared to Parmesan?
[00:13:39] Jakub
Yes, quark has about 100–120 mg, while Parmesan can have 800 to 900 mg. If you want to increase your protein intake—typically for strength athletes, children, or women who struggle with protein—dairy products are a great source. But if you’re unaware, you can easily overdose on calcium. Yogurt, kefir, whey, Parmesan, cheeses—you can easily exceed the recommended intake.
[00:14:55] Michal
So if I combine cheese and quark, it shouldn’t be a problem?
[00:15:02] Jakub
If you stick to one serving of dairy a day, you’re safe.
[00:15:08] Michal
So if I stay balanced, I should be fine—even if I occasionally go a bit over?
[00:15:17] Jakub
Exactly.
[00:15:18] Michal
Great, I get it. We can’t give exact instructions, but we have three blog articles on calcium. Are we preparing something new or updating it based on this episode?
[00:15:36] Jakub
The main emphasis is that you can’t just calculate everything based on nutrition charts. Calcium isn’t the only thing we should be monitoring. Deficiency is known, but excess can also be a problem.
[00:15:55] Michal
That’s not a very popular topic, right? But let’s now focus on specific target groups like pregnant women or people with osteoporosis. What should I pay attention to in the diet to make sure everything works as it should? I assume vitamin D is discussed the most.
[00:16:18] Jakub
Yes, vitamin D regulates calcium absorption, but if there’s enough calcium in your diet, it works even without it. Calcium is absorbed through a concentration gradient—if there’s enough of it in the food.
[00:16:37] Michal
So if I have enough calcium, vitamin D isn’t that crucial?
[00:16:39] Jakub
Exactly. And the same applies to magnesium. If you have a healthy stomach, absorption takes place throughout the digestive tract, including the colon. What matters more is mineral balance. Vitamin D improves calcium absorption only if you’re deficient in calcium.
Why combine calcium with vitamins D3 and K2?
[00:17:22] Michal
The ideal is to have vitamin D within the optimal range.
[00:17:26] Jakub
No doubt about it—but it’s not mainly because of calcium.
[00:17:29] Michal
And what’s the second most important factor?
[00:17:49] Jakub
Vitamin K2 is important for activating bone cells that incorporate calcium into bone tissue—or remove it when necessary.
[00:18:10] Michal
So with vitamin K2, calcium is better utilized in the body.
[00:18:15] Jakub
Exactly. If you have both vitamin D and K2, calcium bioavailability is significantly improved.
[00:18:23] Michal
So when I have both D and K2, calcium is absorbed more efficiently and doesn’t pose a risk?
[00:18:36] Jakub
If you have sufficient levels of D and K2, calcium is safe.
[00:18:40] Michal
And if there’s excess calcium in the blood, does it go where it’s supposed to—into bones and teeth?
[00:18:52] Jakub
Yes, exactly. Calcium in the body is regulated to go where it’s needed.
[00:19:04] Jakub
Any other factors we need to keep in mind?
[00:19:15] Jakub
Other factors depend on the source of calcium in supplements, but the main thing is that the balance of minerals is key.
[00:19:41] Michal
For pregnant women, would the risk of calcium overdose be minimal—especially in the second and third trimester?
[00:20:14] Jakub
Yes, calcium requirements increase during pregnancy because the baby needs calcium for bone development. If the pregnant woman is deficient, it can affect her health—not the baby’s.
[00:20:30] Michal
So the pregnant woman draws calcium from her own bone mass?
[00:20:47] Jakub
Yes. If there’s not enough calcium, the body compensates by increasing the activity of osteoclasts, which draw calcium from the bones.
[00:20:53] Michal
So what’s the nutritional advice for a pregnant woman?
It’s important to eat enough vegetables. Two servings a day provide about 50–100 mg of calcium, although the bioavailability varies.
So if I add a portion of Parmesan each day, I should be safe.
[00:22:26] Jakub
Yes, cheeses are by far the best source of calcium.
[00:22:52] Michal
So especially in the third trimester, it’s important to pay close attention to this.
[00:22:56] Jakub
If you’re on a dairy-free diet, I would definitely emphasize calcium. For pregnant women, supplementation is justified because getting enough calcium from diet alone can be very difficult. If the intake is on the lower end, you really need to focus on maximizing calcium absorption—which can be quite demanding.
[00:23:21] Michal
If a pregnant woman is unsure, it’s better to slightly increase calcium intake. Three months of slightly higher intake won’t do any harm. It’s better to have a bit more than too little.
[00:23:37] Jakub
Definitely. If supplementation is well-designed, it will also include other components like vitamins D, K2, and magnesium. So it’s not just about calcium alone. Some supplements contain only calcium citrate, but it’s better to take a more comprehensive approach.
[00:24:10] Michal
Nowadays, magnesium supplementation is a big trend—they say it’s the number one supplement. If I take magnesium in higher doses, what should I watch out for in relation to calcium?
[00:24:30] Jakub
If you take magnesium in small amounts, there’s no problem. But in higher doses, it can interfere with transport systems and compete with calcium. If you supplement large amounts of magnesium, it may not be ideal—especially for pregnant women. It’s important to avoid extremes.
[00:25:13] Michal
You can overdo magnesium, right?
[00:25:14] Jakub
Yes, definitely. If you’re supplementing 400 mg, it could lead to calcium deficiency.
[00:25:27] Michal
Interesting. We’ve covered pregnant women, but a lot of people suffer from osteoporosis. In the Czech Republic, it’s one in three women and one in five men over 50. That seems like a lot to me.
[00:25:47] Jakub
Yes, exactly. If DXA scanning were used more widely, the numbers would probably be even worse. Most people don’t even know they have osteoporosis.
[00:25:57] Michal
When do you usually find out you have it?
[00:25:59] Jakub
Usually when you break a bone. That’s how it gets diagnosed in regular practice.
[00:26:04] Michal
And what about treatment in practice? What do you think?
[00:26:30] Jakub
The solution isn’t just to increase calcium intake, whether through supplements or diet.
[00:26:38] Michal
It doesn’t make it to the bones anyway.
[00:26:39] Jakub
Exactly. Just increasing calcium doesn’t improve the condition. Long-term studies show that excessive calcium intake may be associated with an increased risk of cardiovascular disease.
[00:26:53] Michal
We know that a vitamin D deficiency can reduce calcium absorption by up to 50%, and that combining vitamin K2 with D can improve calcium incorporation into bones by 25%.
[00:27:30] Jakub
If you have osteoporosis, the foundation is enough calcium from food—ideally around 700 mg per day. But for diagnosed osteoporosis, it’s also crucial to maintain optimal vitamin D levels—around 150 nmol/l. These levels should be monitored, ideally twice a year. The test is simple—either via DBS (dried blood spot) or standard blood draw.
[00:29:17] Michal
If I have quality sources, like regenerative agriculture or backyard eggs, I should be fine.
[00:29:22] Jakub
If the diet is varied, there’s no problem. Vegans may struggle with calcium intake, but if they’re well-informed, they can have the best sources with the highest bioavailability.
[00:30:13] Michal
If your diet is diverse, you can get enough calcium—even if you’re not living on “white bread.”
[00:30:27] Jakub
Exactly. And if you’re consuming a variety of sources—like fermented foods or quality animal products—your body will absorb it better than from a typical mixed diet. Vegan diets can struggle with bioavailability because some minerals bind into indigestible complexes.
[00:30:39] Michal
If I focus on regenerative agriculture or backyard eggs, that’s okay then?
[00:30:50] Jakub
Yes, that’s ideal. Sources with high bioavailability—like fermented foods and quality animal products—are the most efficient.
[00:32:06] Michal
Comprehensive statistics—it’s not easy. Sometimes they show problems, but…
[00:32:11] Jakub
That’s the thing—when you know about it, it requires commitment. If you eat everything in the highest quality possible, you shouldn’t drift into extremes.
[00:32:18] Michal
Exactly—that’s the key. Finding balance.
[00:32:29] Jakub
Most things come down to the fact that what we consider “normal” eating today is actually also extreme. So both vegans and “meat lovers” can run into problems if they don’t care about balance. A vegan focuses on one component, while a meat eater focuses on another.
[00:32:59] Michal
Women are affected more, mainly due to osteoporosis, right?
[00:33:04] Jakub
Yes, it’s a combination of hormonal profile, lower skeletal muscle mass, and of course menopause. Dietary habits contribute too—but it’s hard to pinpoint a single cause.
[00:33:21] Michal
It’s hard to research precisely, isn’t it?
[00:33:24] Jakub
Yes—most things in nutrition are hard to study.
[00:33:31] Michal
What’s your estimate in practice? How many people get too little calcium and how many get too much?
[00:33:43] Jakub
Hard to say. I’d rather divide it by group. If we look at overall calcium intake, it shouldn’t be a problem—but balance and homeostasis are key. If your intake is low, focus on factors that enhance calcium use. If it’s too high, watch out for micronutrients that can neutralize potential toxicity.
[00:34:31] Michal
So balance above all. That’s clear.
[00:34:45] Jakub
Yes, the takeaway should be that the amount of calcium you take in isn’t as important as how well your body uses it—and the overall balance.
[00:35:43] Michal
We’d like to introduce our new calcium product. Why did we decide on a plant-based calcium source from algae?
[00:35:55] Jakub
There are several options for sourcing calcium—for example, eggshells or other types of algae. This algae source is environmentally friendly because only washed-up algae are collected, not harvested from the seabed. We also have better properties thanks to the presence of other minerals that support calcium homeostasis, including strontium, which helps activate bone cells.
[00:36:28] Michal
For us, it was important that the source be ecological and that no ships be used to plunder the oceans. These are just washed-up algae.
[00:36:35] Jakub
Exactly. We spent a long time deciding between eggshells and algae, but this source has better parameters in terms of additional mineral content. It’s sun-dried, hand-harvested, and thanks to the processing technology, the calcium has high porosity, which improves its usability.
[00:37:09] Michal
This concept respects how nature designed it.
[00:38:14] Jakub
The usability of this calcium is good even if your stomach conditions aren’t ideal. This type of calcium allows better absorption even with low stomach pH.
[00:38:29] Michal
We decided to include calcium in our product only in combination with vitamins D3 and K2—we don’t offer calcium on its own. Jakub explained it well—this approach is safer for the customer.
[00:39:21] Jakub
It was hard to find the right ratios so that the dosing made sense and there was no risk of overdosing on vitamin D or K2. What’s important is that even the basic dose includes effective amounts of these vitamins, which support homeostasis.
[00:39:41] Michal
Great—we have it set up that way. Is there anything else you’d like to add?
[00:39:44] Jakub
That’s all.
[00:39:45] Michal
We’d love to know what you think about this topic. We’ve received feedback that it’s too technical, but we focus on people who want to go deep. Basic info is easy to find these days—we want to offer more detailed explanations.
[00:40:07] Jakub
Goodbye.
