When you mention a calcium deficiency, people freak out.
Most people associate calcium with bone strength. Without enough, your bones break.
And it gets worse.
Broken bones mean you’re stuck in casts (and in pain). This leads to being out of work, relationships ending and further unraveling of your life.
Or, something like that.
Well, guess what? Most people are right about the importance of calcium!
But, only to some extent.
Shall we discuss?
Why we Need Calcium
Let’s do a quick refresher on calcium.
It’s a mineral.
You know when people say “this is full of vitamins and minerals”?
Calcium is one of those minerals.
And we, as humans, need those minerals to survive.
It supports critical metabolic functions
You know all those things your body does without you asking? Oh, you know:
- Vascular contraction.
- Vasodilation (defined here).
- Muscle function.
- Nerve transmission.
- Intracellular signaling.
- Hormonal secretion.
Yeah, calcium assures we can do that stuff. But only 1% of the calcium we ingest goes towards those efforts.
The other 99%?
It helps build strong bones.
We store 99% of the calcium in our bones. Makes sense.
Just as we learned in grade school: We need calcium for our bones.
While it’s a bit more complicated than that, let’s keep it simple. You’re more likely to break bones if you have a calcium deficiency than if you don’t.
But we knew all those things. Here’s what you might not have known about calcium.
6 (more) things you might not have known about calcium
Nobody hearing you’re wrong. But you might have been academically incorrect about a few things related to calcium. Here they are.
Not all calcium is created equal
People often ask, “But doesn’t cow’s milk have the most calcium?”
Yes, there is a lot of calcium in cow’s milk.
But let’s look a bit deeper.
Your body absorbs just a portion of the calcium you consume. The rest is excreted (peed out).
So while one cup of milk has 300 mg of calcium, only about 30% of it is actually absorbed.
What plants have an equivalent amount of calcium?
- 1 cup bok choy.
- 1 1/2 cup kale.
- 2 cups broccoli.
But, your body absorbs so much more of the calcium from these green vegetables (between 50% – 60%)
They call this ability to absorb “bioavailability.”
Think about it like comedians. Some say things that make you laugh 30% of the time. Others, the really good ones, make you laugh over 50% of the time.
Wouldn’t you prefer the witty comic to the hack comedian?
Your body adjusts to too much, too little
The human body is a cool thing. It adjusts to its surroundings to stay alive.
It’s adjustment to calcium intake is no exception.
If you’re low on calcium, say 400 mg per day, your body adjusts. It becomes more efficient in absorbing calcium and the kidneys conserve it better.
Ingest too much calcium? No problem either. Your kidneys stop accepting the calcium, and you pee out what it isn’t need.
Sure, the on-the-fly adjustments you make from too much or not enough calcium takes energy. But it’s a completely normal, everyday process.
Calcium wasn’t meant to be convenient
Think about the ways you can get calcium. What comes to mind first?
- Cow’s milk?
- Fortified drinks like almond milk or OJ?
These sources require absolutely zero effort.
It’s kind of like feeding yourself a microwave dinner. Sure, the contents of the box have everything you need. But is it really the best approach?
Clearly, the answer is no.
Sure, those things are okay. But they should never be the sole source of calcium.
Any guess what can?
You can get enough from just plants
It’s true. You can get all the calcium you need from plant-based sources, alone.
Calcium, like magnesium and iron, are minerals. Minerals live in soil.
Any guess what else lives in soil?
Plants absorb these minerals while in the ground.
And that’s how plants have calcium inside.
Any guess how animals get calcium?
Yup. They eat plants.
Let’s take it from Rosane Oliveira, DVM, PhD and Founding Director of the UC Davis Integrative Medicine program and Adjunct Assistant Professor at the Department of Public Health Sciences at the School of Medicine at the University of California, Davis.
She says quite simply, “plants have sufficient calcium to meet our needs.”
Exactly what plants should we focus on?
Here are some plants that are LOADED with calcium:
- Bok choy.
- Turnip Greens (Admittedly, I had to google what these look like.).
And if you’re not into plants, no problem.
If you do that math, you might think it’s tough to get the recommended 1000-1200 mg of calcium per day.
This is true.
But here’s why that math doesn’t really add up.
You might not need as much as you think
Some nutritionists recommend 1000-1200 mg of calcium per day.
That’s quite a bit of calcium. Why?
This recommendation is based on a diet full of animal proteins. Meat, dairy, etc.
Why does that matter?
Animals proteins cause you to excrete a lot of calcium.
With a primarily plant-based diet, calcium requirements go down significantly.
One study says people with low levels of animal protein and sodium can require a lot less calcium (500-700 mg per day).
Quite a bit less, huh?
Bringing it all together
In researching for this article, it was clear that people have STRONG beliefs about calcium (especially in relation to cow’s milk). I decided to save the “Why the hell do American pediatricians and nutritionists push milk so hard while experts from other countries don’t at all?” question for later when I update my milk post.
But for today, my recommendation is this:
Don’t worry so much about getting enough calcium. It’s one of those things that you body will tell you it needs (via cravings for certain foods). By eating fewer animal products (and more plant-based foods), you will probably need less calcium, feel better in general, and maybe even save the world.
American Journal of Clinical Nutrition http://ajcn.nutrition.org/content/86/4/1054.abstract
National Institutes of Health http://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/