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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Is calcium supplementation a good idea?

Two recent studies raised the possibility that calcium supplements may increase the risk of cardiovascular disease. Consequently, a number of readers have wondered if they should take calcium, and if so, how much. As most people reading know, this is an important question relating to vitamin D, as vitamin D increases your ability to absorb calcium.

Professor Robert Heaney of Creighton University, together with Dr. John Hathcock and others at the Council for Responsible Nutrition, recently reviewed all the studies on calcium supplements and cardiovascular disease.

Heaney RP, Kopecky S, Maki KC, Hathcock J, Mackay D, Wallace TC. A review of calcium supplements and cardiovascular disease risk. Adv Nutr. 2012 Nov 1;3(6):763-71.

The authors made several points, including the following:

  1. Calcium is the fifth most abundant element in the human body, with >99% residing in the skeleton.
  2. Thousands of milligrams of calcium passively diffuse into and out of bone on a daily basis.
  3. The kidneys filter as much as 10,000 mg of calcium each day, with ~98% retained by the kidneys.
  4. Fifty-four percent of Americans did not meet the estimated average requirement for calcium with diet alone.
  5. Emerging evidence suggests that calcium supplementation may be associated reduced risk of the development of colon polyps, cancers, and pre-eclampsia.
  6. Over the last two decades, calcium supplementation has been increasing, with 43% of the US population and 70% of older women now using calcium supplements. During this same time, cardiovascular disease has been steadily decreasing.
  7. Studies show calcium slightly increases cardiovascular disease, a few show it slightly decreases cardiovascular disease, but most show no effect on cardiovascular disease.
  8. Among 16 studies reviewed in this article involving >358,000 individuals, there was no indication of a connection between calcium intake and atherosclerotic heart disease or stroke.

That said, some people take too much calcium. They don’t seem to realize that calcium intake recommendations are for total calcium intake, not supplement intake. It is very difficult to get no calcium in your diet. Also, realize that higher vitamin D levels will increase calcium absorption, up to 32 ng/ml at which point higher levels will not increase absorption any further.

If you continue to supplement with calcium, be sure to estimate your dietary intake, subtract it from the amount recommended for your age, and supplement with the remainder. It is probably better to get calcium through your diet than through supplements, which usually means some form of dairy consumption, but don’t forget calcium is also in things like fish (with bones) and green vegetables.

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

5 Responses to Is calcium supplementation a good idea?

  1. Rebecca Oshiro says:

    Some excellent insight into the calcium debate:


    My primary source of calcium is Vital Choice sardines:


    One can has almost as much calcium as 3 glasses of milk! Most people are horrified when I recommend sardines as a source of calcium, but if you like to eat any other fish (especially tuna) I can almost guarantee you will love these. Almost all sardines in the grocery store are rancid because of the delay between catching the fish and canning them, but Vital Choice cans on the spot. They use a high quality extra virgin olive oil and actual, whole peppers to top it off. You have to taste it to believe it.

    P.S. I don’t have any connections to this company (but should for the amount of publicity I give them :)

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  2. Erroring on the safe side: 500 mg of both Calcium and Magnesium

    There is a lot of controversy about how much Calcium to take.

    Some say

    No Magnesium controversy however: 500 mg of Magnesium ELEMENT ( not compound)

    Details with graphs at http://is.gd/cofactord1

    You should also increase the other Vitamin D co-factors: Vitamin K2, Boron, Silicon, Zinc, etc. Fortunately many companies now provide most of the cofactors with or without vitamin D as a package – in the form of pill, liquid, or fizzy drink.


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  3. kenmerrimanmd says:

    so I was wondering what you thought would be an appropriate level of calcium supplementation

    in someone who does not use dairy products / or is allergic to fish ( as I am) I hear tell that sesame seeds ect are very rich in Ca++

    also what is your take on carbonate vs citrate seems to me that for many people the citrate might be a better option( although you need to read the bottle carefully as most people under dose it)

    many of my patients kind of “freaked out’ with the release of those negative Ca++ studies but thankfully a large number also don’t much trust what they read in the paper or hear on TV so it didn’t seem to have too much long term impact


    ken merriman md

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  4. Ian says:

    According to this we should consider potassium citrate alongside Vitamin D rather than supplementing with additional calcium.


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  5. This subject is fascinating to me. Calcium supplementation becomes a problem when calcium is deposited in the coronary arteries. Contrary to popular belief calcification in the coronaries IS the leading indicator of heart attack. What tells calcium to go to the right place or the lack of the wrong place? What causes calcium in the coronary arteries to leave the coronaries and go where it is supposed to. The simple answer is vitamin K2. Fermented foods is the natural source and a good cheap source is home made fermented foods daily. I make sauer kraut…….

    Bruce Bennett CRNA Retired

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