Why not to take Calcium supplements

by Christina on October 14, 2016

Yesterday, my younger sister texted me asking if I think it’s okay for her to take a chocolate calcium supplement, and that actually she likes the taste so much that she has been having two per day.

I quickly texted her back — no, not okay!

As I review medications and supplements with my patients, I often discover they are taking a calcium supplement because they think this is good for their bones. I then spend a lot of time recommending they stop their supplement, and instead make sure to get sufficient calcium through food.

There’s more evidence coming out that calcium supplementation may actually be dangerous. This study published this week looked at calcium intake (through both diet and supplementation) of over 2700 patients and compared coronary artery CT scans over a 10 year period.

They found that taking a calcium supplement was associated with an increased risk of coronary artery calcification. Interestingly though, it seems that only the calcium supplements increase risk, while a calcium-rich diet was protective.

Here’s a nice article in Science Daily summarizing the study’s findings:calcium

The bottom line — try to get the calcium you need from your food. For postmenopausal women this is 1200 mg per day. For other women this is 1000 mg per day. For men this is 1000 mg per day (men over 70: 1200mg per day).

It is not hard to meet these requirements with a balanced, whole foods diet. Food sources of calcium include dairy products, leafy greens, nuts and seeds, soy and almond milk, cereals, and fish.

Here are some examples of foods and their estimated calcium amounts:

  • Yogurt (1 cup): 450 mg
  • Soy/Almond milk (1 cup): 200-400 mg
  • Spinach (1 cup cooked): 240 mg
  • Broccoli (1 cup cooked): 180 mg
  • Figs (dried, 1 cup ): 300 mg
  • Tofu (4 oz, calcium set): 250-750 mg
  • White beans (1/2 cup cooked): 70 mg
  • Almonds (1 oz): 80 mg
  • Sesame seeds (1 oz): 280 mg

(More details on dietary sources of calcium from UCSF here and NIH here)


{ 4 comments… read them below or add one }

Chris October 14, 2016 at 8:12 pm

What an excellent blog post!


Mike boucher October 16, 2016 at 12:00 am

What do you think of K2 and D3 to help with osteoporosis? My wife and several friends think the evidence is compelling.


Christina October 16, 2016 at 12:40 am

Hi Mike! Nice to hear from you – hope all is well!

Yes, I agree D3 and K2 are very important. Vitamin K2 is hugely important and something we’re just starting to learn more about. It plays a big role in helping calcium go to the correct places in the body (to bones instead of arteries), and is mostly found in animal products like grass fed dairy products and egg yolks, as well as fermented foods (like natto). I wondered if the study findings above might be because of the imbalance of Ca with K2 in the group taking calcium supplements, whereas those getting calcium from dairy were getting more K2 from their diet and helping calcium get deposited in the right places.

Most people do need Vitamin D supplementation since we don’t get enough sunlight, and I’ll often recommend people take K2 (or make sure they get plenty through their diet) in addition to their Vitamin D supplement since they work together in the body.


Mike boucher October 20, 2016 at 1:17 am

Hi Christina,

Thanks for the reply! I just noticed it now. I didn’t know about natural sources of K2, that is pretty interesting.

And thanks for writing the blog! It’s always interesting.


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