Do you know how much calcium you’re really getting from your food?
I’m not talking about how much calcium is in the food you eat. I’m talking about how much of that calcium your body actually absorbs. Scientists call it bioavailability.
Here’s what it means.
Let’s say you’re very careful to eat a cup of yogurt every day for your bones. After all, dairy is high in calcium, right? You figure out from the label that your yogurt has about 300 milligrams of calcium. That sounds great. But the problem is your body can’t use all that calcium.
In fact, you can only use about 100 milligrams of it. You see, our bodies generally absorb only about 32% of the calcium from dairy products.
So you might think you’re getting plenty of calcium from dairy but maybe you’re not.
The flip side is also true. You might not think of vegetables as high in calcium. For example, a one-cup serving of Brussels sprouts contains about 56 mg. But your body can use a whopping 64% of that calcium. It’s twice as bioavailable as dairy calcium.
Other vegetables with high bioavailability of calcium include broccoli (61%), kale (59%), mustard greens (58%) and bok choy (54%).
So even though veggies don’t have as much total calcium, when you consider their better absorption rate, it can add up to plenty.
And vegetable sources of calcium have another benefit. They come naturally packaged with potassium and magnesium. Those are nutrients you also need for strong bones. That may be why researchers have found that people who eat the most fruits and vegetables have denser bones.[i]
Leafy greens are particularly powerful when it comes to reducing hip fractures. They’re rich in vitamin K, which is critical for bone health.[ii]
And unlike dairy, fruits and vegetables are alkaline. They don’t produce acid so they don’t cause your body to lose calcium through the urine.
Here's a typical conversation that I had recently:
New friend: "Oh yes, I have osteopenia and I'm doing everything I can for my bones. I'm taking my calcium supplement, eating my yogurt and lots and lots of spinach".
Not the right recipe for bone strength.
Just remember that some greens are better than others for getting your calcium. Spinach, Swiss chard, and beet greens have very high levels of oxalic acid. This compound binds to the calcium in the greens and blocks your body from absorbing it.
For example, spinach contains about 230 mg of calcium per cup. But because of high oxalic acid levels, you’d have to eat about eight cups of spinach to get the same amount of calcium as one cup of yogurt.
You can reduce the oxalic content of greens by cooking them. One study showed that boiling spinach reduces oxalic acid by 87% and steaming reduces it by 42%.[iii]
And this doesn’t mean you have to avoid vegetables that are high in oxalic acid. Just don’t rely on these foods for your calcium. These greens are still an excellent source of folic acid, potassium, magnesium, vitamin K, carotenes, and vitamin C.
Make sure you get a wide variety of vegetables and your bones will have everything they need.
Here's my favorite summer salad:
Arugula, Watermelon and Kalmata Olives or Feta
Arugula's nutrient dense profile
Vitamin K, Vitamin C, Vitamin B9, Calcium, Magnesium, Manganese. Low is Oxalates
1/4 cup balsamic vinegar
1/2 cup high quality organic olive oil
1 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
6 cups baby arugula, washed and spun dry
1/8th seedless watermelon, rind removed, and cut in 1-inch cubes
12 ounces good feta cheese, 1/2-inch diced OR 1-2 cups of pitted Kalamata Olives chopped
1 cup (4 ounces) whole fresh mint leaves, julienned
Whisk together the balsamic vinegar and olive oil whisking constantly, to form an emulsion.
If not using within an hour, store the vinaigrette covered in the refrigerator.
Place the arugula, watermelon, feta, (or kalamata olives) and mint in a large bowl. Drizzle with enough vinaigrette to coat the greens lightly and toss well. Taste for seasonings and serve immediately.
Some enjoy thinly sliced red onions to dress up this salad.
For a dairy free version: substitute feta cheese with kalamata olives - pronounced: kahl-uh-MAH-tuhHydroxytyrosol, an olive phytonutrient that has long been linked to cancer prevention, is now regarded as having the potential to help us prevent bone loss as well. Several recent laboratory animal studies have found increased depositing of calcium in bone and decreased loss of total bone mass following consumption of this olive phytonutrient (as well as oleuropein, another key phytonutrient found in olives).
These findings are fascinating, since consumption of a Mediterranean Diet has long been associated with decreased risk of osteoporosis, and olives often find themselves on center stage in Mediterranean Diet studies. [iiii]
When it comes to choosing the right foods to optimize your bone health, what is the single biggest challenge, frustration or problem you’ve been struggling with?
Please let me know so I can write content that meets your needs.
Plus I have wonderful alkaline salad dressing waiting for you on the other side to thank you for your time 🙂.
From my delicious bones to yours,
Irma Jennings, INHC
Holistic Bone Coach
Physician’s Committee for Responsible Medicine, “Ask the Expert: Calcium.” https://pcrm.org/health/cancer-resources/ask/ask-the-expert-calcium
Bottom Line Health, “How to Get a Lot More Nutrients From Your Foods…” https://www.bottomlinepublications.com/content/article/diet-a-exercise/how-to-get-a-lot-more-nutrients-from-your-foods
salad: skinny taste gina