Calcium is an essential nutrient that is necessary for many functions in human health along with other benefits.
Maybe you have (or want to prevent) osteoporosis, and you heard that calcium builds strong bones and teeth. Maybe you heard that calcium is good for high blood pressure and can lower it. Or maybe you just want to increase your calcium intake for other reasons.

Either way, you stumbled across this article because you have some reason to eat more calcium-rich foods.
There are a ton of misconceptions about calcium, so in this article well:
- Debunk some common myths about calcium
- Explain what calcium does
- Give you a breakdown of how much calcium you should be getting based on your age and sex
- And finally, another breakdown of what are your best sources of calcium But, before we get started, let me introduce myself!
Hi 🙂
My name is Igor, and I’m the author of the Amazon bestselling book, Osteoporosis Reversal Secrets. Im also a certified personal trainer who specializes in helping clients with osteoporosis, so I can say I have a good understanding of calcium.
And if you want to see other myths busted, you can get a free chapter of my osteoporosis book (10.5 Osteoporosis Myths That Are Harming Your Health) by just filling out the form below. In that chapter, I cover myths about protein (does it help or hurt bones?), coffee, carbonated drinks, sugar, bone density and more.
So, without further ado, lets get started with our first topic.
Debunking Calcium Myths
Its not unusual for misinformation to spread, especially with the internet nowadays (and just a tip, don’t always trust the information you hear without researching). Unsurprisingly, the same is true for calcium, so Ill be covering 4 myths, starting with:
Myth 1: Calcium is Good for Osteoporosis
This myth may be the biggest shocker to you (as it was for me) because we grew up thinking milk and calcium strengthens bones. If calcium makes our bones stronger, shouldnt that mean it can help with osteoporosis? Nope. Turns out, study after study after study have shown that high-calcium diets are no better than low-calcium diets when it comes to improving osteoporosis.
Heres one for example. One particular study divided postmenopausal women into 4 groups:
- Group 1 consumed less than 400 mg of calcium a day
- Group 2 consumed 400-800 mg
- Group 3 consumed 800-1200 mg
- Group 4 consumed over 1200 mg a day.
Even comparing the vast difference of calcium consumed between group 1 and group 4, there was barely any difference in the number of broken bones. Calcium may increase bone density, but not your fracture risk (which is what we really want to achieve).
Myth 2: Calcium is Good for High Blood Pressure.
Unfortunately, this is yet another benefit that calcium sadly does not have. One meta-analysis shows that calcium has no impact on high blood pressure at all. Another meta-analysis only showed a drop of only 1-2 mmHg, which is basically nothing.
This is self-explanatory, dont expect calcium to help fix your high blood pressure. However, the message that may have been confused and started this myth is that calcium can play a part in prevention (which is covered later in the article).
Myth 3: All Calcium Sources are Created Equal (Bioavailability)
Chances are, youve already looked at some calcium-rich foods and noticed how some foods had more calcium than others. But theres more to calcium than sheer amount.
We know that each food has a certain amount of calcium, but not all of the calcium is absorbed into your body. Maybe its half or even less. Thats what bioavailability is – the percentage of calcium absorbed. In reality, a food with a seemingly high 250 mg of calcium with 10% bioavailability will only provide a mere 25 mg of calcium.
And just so you know, bioavailability does not only apply to calcium. Other minerals in foods have their own bioavailability rates or percentages.
Youll see the bioavailability of different foods later in this article.
Myth 4: Green Leafy Veggies are the Best Sources of Calcium
Some veggies like kale and collards are relatively high in calcium, so I understand why some think that green veggies are the best sources of calcium. What everyone is missing is that most veggies dont have that much calcium, some have low bioavailability, and also you dont usually eat high amounts of them. After all, its easy to eat 200-300 grams of potatoes or rice, but it would be seriously difficult to eat 200-300 grams of a salad. So we cant even do a fair gram-for-gram comparison, because we just dont eat as many grams of salad as we do of other things, like meat and starches. A better comparison would be serving-for-serving. But, this is just a short explanation, so keep reading if you want a more detailed explanation.
Benefits of Calcium
After these myths, you might be a little confused on what calcium actually does. If it doesn’t help with osteoporosis, and it doesnt decrease high blood pressure, what does it do?
Well, the benefits of dietary calcium are the prevention of kidney stones and high blood pressure. I know this might contradict what I said earlier about calcium does not lower high blood pressure, so I want to emphasize that calcium only helps on the prevention side of things. If you already have kidney stones or high blood pressure, consuming calcium will not treat your condition.
Also another detail worth mentioning is that the benefits only apply to food, not supplements, because calcium supplements produce different effects. This study shows that supplements might even raise the risk of cardiovascular disease and kidney stones. They recommend eating food for calcium, and only take supplements if you have to, with a limit of 500 mg.
And thats basically the benefits of calcium – but I’m not saying that this is all that calcium does. Calcium plays a role in muscle contractions, including those in the skeletal muscles (such as your biceps), smooth muscles (around blood vessels), and cardiac muscle (heart). So having enough calcium is still good for you, even if its not providing the benefits you wanted.
Although, it’s important to note that getting more calcium than needed does not provide additional benefits. In fact, too much calcium can be harmful.
Speaking of calcium requirements, there are recommended calcium you need based on your age and sex.
Calcium Requirements
See the table below for how much daily calcium is recommended for your age (from the National Institutes of Health)
Age | Recommended Calcium | Tolerable Upper Intake Level (UL) |
Babies 0-6 months | 200 mg | 1000 mg |
Babies 7-12 months | 260 mg | 1500 mg |
Children 1-3 years | 700 mg | 2500 mg |
Children 4-8 years | 1,000 mg | 2500 mg |
Children 9-18 years | 1,300 mg | 3000 mg |
Pregnant and lactating women 14-18 years | 1,300 mg | 3000 mg |
Pregnant and lactating women 19-50 years | 1,000 mg | 2500 mg |
Adult males 19-70 years | 1,000 mg | 2500 mg |
Adult females 19-50 years old | 1,000 mg | 2500 mg |
Adult males 71+ years | 1,200 mg | 2000 mg |
Adult females 51+ years | 1,200 mg | 2000 mg |
Though to be fair, these recommendations are under hot debate, since:
- The way that the government came up with those recommendations is in the 1940s, they analyzed the nutrient intake of apparently healthy people. The problem is that they didnt compare the nutrient intake of apparently healthy people to unhealthy people. What if healthy and unhealthy people had the same calcium intake? After all, as I pointed out, in an earlier meta-analysis, research showed that theres no difference in fracture risk between people with a high and low calcium intake.
- It doesnt take into account peoples size and activity levels. After all, does a petite 110-lb woman need the same amount of calcium as a 250-lb man? Probably not.
- Personal requirements differ even between people of the same age and size.
Finally after clearing up what calcium is actually good for and busting all those myths, now we can get into what you are most interested in: the best sources of calcium.
The Best Food Sources of Calcium
When it comes to checking the calcium content in food, we have to look at how many milligrams are per serving. Why per serving? Why not a standardized 100 grams (for instance)? Because its not fair to compare every food at 100 grams, if thats not how its actually eaten.
For instance, according to the USDA, on a per-100 gram basis, celery seeds are a clear winner, at 1770 mg. The thing is that nobody eats 100 grams of celery seeds (thats almost a quarter pound of celery seeds). Theyre a seed. Typically, you measure seeds by teaspoons. And a single teaspoon is only 5 grams.
Or another example: 2 cups of raw spinach only have about 30-40 grams of calcium. Again, you dont really eat 100 grams of raw spinach. That would be 5-6.5 cups of spinach.
Also, at the other end of the spectrum, if youre drinking a beverage (like milk), a typical serving is a cup. Thats 250 grams (or ml, as it were).
Thats why I like to compare foods using real life servings since theyre the most accurate. Now keeping that in mind, here are the 10 best sources of calcium based on their normal servings (again, according to the USDA):
# | Food Source | Calcium Contained |
1. | Fried tofu | ~744 mg in 200 grams |
2. | Almond milk | ~415 mg per cup |
3. | Soy milk | ~390 mg per cup |
4. | Oat milk | ~370 mg per cup |
5. | Sardines | ~350 mg per can |
6. | Plain yogurt with whole milk | ~320 mg per cup |
7. | Milk (both 1% & 2%) | ~315 mg per cup |
8. | Parmesan cheese | ~280 mg per cube |
9. | Canned salmon | ~275 mg per can |
10. | Cheddar cheese | ~210 mg per slice |
Believe it or not, 8 of the best sources of calcium are actually dairy products. So, if you’re in need of a calcium boost, consider chugging a gallon of milk (just kidding, of course, unless).
This is another example as to why green vegetables are not your best sources of calcium. None of them are in the top 10 list. If you still think veggies are high in calcium, I hate to be the one to break it to you (except I’m kind of enjoying it), but thats all vegan propaganda .
Calcium in Green Veggies
You might ask, what about the typical arguments of the vegan community? Bok choy, they say, is high in calcium. Nope. Bok choy contains about 53 mg of calcium per 2 cups. Vegans will argue that it has a high bioavailability (which is true – 54%), but even if you count only absorbed calcium, its pretty low. You dont get bonus points for high bioavailability if the total calcium is still very low.
Vegans like to advance their ideology by messing with the numbers. Theyll tell you that on a per-gram basis, green leafy veggies are high in calcium. First of all – no. Only kale and collards can be considered high compared to other veggies. Not compared to the true calcium powerhouses – the ones mentioned in the earlier section.
Second of all, let me reiterate my point from earlier – even if they were high on a per-gram basis (which again, theyre not), you just dont eat as many grams of kale as you do a glass of almond/oat/soy milk (which, I dont get the vegans argument – they could argue for those types of milk, since theyre vegan anyway). It would take a will of iron to chow down that much greens.
So just remember that green vegetables being the best calcium source is just nonsense. They do contain calcium, but shouldnt be regarded as exceptionally high. Here is the list of calcium contained in some green veggies (you can look this all up yourself in any nutrition database):
Green Vegetable | Calcium Contained |
Kale | 127 mg per 2 cups |
Spinach | 25-30 mg per 2 cups |
Okra | 33 mg per 2 cups |
Broccoli | 34 mg per 100 grams |
Bok choy | 50 mg per 2 cups |
Collard greens | 115 mg per 2 cups |
As you can see, not a lot of calcium inside these compared to the list before. Sorry, heroes of the vegan world – thats a bunch of nails in your coffin.
Other Calcium Sources
A lot of the other calcium sources are the same as green veggies. They seem rich in calcium on a per-gram basis, but in reality, they arent that high considering how much is actually eaten and its bioavailability.
Some seeds for example are incredibly high in calcium, but youll probably never eat enough in a day to make it worth your while. Poppy seeds have 1440 mg of calcium in 100 grams, which translates to 72 mg per teaspoon. Or even chia seeds which have 630 mg of calcium per 100 grams, but in a teaspoon, its only about 32. Thats a gigantic difference.
Anyways, here is another list of calcium sources to broaden your choices:
Food Source | Calcium Contained |
Poppy seeds | 72 mg per teaspoon |
Chia seeds | 32 mg per teaspoon |
Sesame seeds | 50 mg per teaspoon |
White kidney beans | 90 mg per 100 grams |
Lentils | 40 mg per cup (200 grams) |
Figs | 22 mg per fig |
Almonds | 273 mg per 100 grams (575 calories) |
Orange | 52 mg per orange |
Edamame beans | 60-65 mg in 1 cup |
Whey protein | 95 mg in 1 scoop |
Rhubarb | 150 mg in 100 grams |
Amaranth | 115 mg in 1 cup |
Overall, with a daily calcium requirement of 1000-1200 mg/day, I like to split the foods into categories as:
- Grade A calcium source – 300+ mg of calcium
- Grade B calcium source – 100 – 300 mg of calcium
- Grade C calcium source – <100 mg of calcium And there you have it, your calcium-rich foods.
The Bottom Line
Now for a quick summary: calcium is not good for osteoporosis, not good to decrease high blood pressure, is not equal in all foods, and not the highest in green veggies.
Calcium is good in preventing, but not treating, kidney stones and high blood pressure.
Although its even debatable if the amount of calcium you get makes no difference to fracture risk or other markers of health, whats the true calcium requirement? As it stands now, its still unknown.
Anyways, I hope you learned what foods are the best for you, and if you want help with your osteoporosis, just feel free to fill out the application form on our home page.