Calcium as a factor in men’s health doesn’t get the same attention as calcium for women’s health. But this humble nutrient is essential in the diet and we know about half of men in Canada aged 19-50 do not get enough.1 Let’s talk about why you might need to pay more attention to calcium in your diet for optimal health.

Why You Need Calcium

Calcium is a mineral required by the body to perform many functions, including:

  • Formation and maintenance of bones and teeth
  • Proper muscle contractions
  • Nerve transmission
  • Blood clotting
  • Hormone secretion.2

Since our body cannot make its own calcium, it is classified as an essential nutrient. This means that it must be obtained from the diet to achieve optimal physiological function.

How Much You Need

Various professional bodies suggest the Recommended Dietary Allowance (RDA) for men aged 19-50 is 1,000 milligrams calcium per day, based on data for maintenance of bone mineral density.2,3

The upper limit, which should not be exceeded, is 2,500 milligrams. Most data indicate a high intake level (primarily taken from calcium supplements, often in pill or tab form) poses risk for kidney stones, hypercalcemia — a condition where the calcium level in your blood is above normal — and renal insufficiency, which is poorly functioning kidneys.2

Where Calcium is Found

Bones and teeth contain more than 99 percent of our body’s calcium reservoir, constituting one to two percent of an adult’s weight.2 Our reservoir is sustained from a dietary intake from natural food sources, supplements and calcium-fortified foods, which are foods containing added calcium.

It is difficult to assess nutritional adequacy of calcium, so most researchers track bone mass changes through special imaging. The next best thing is estimating or calculating intake through diet assessment, including:

  • Natural food sources
  • Fortified foods
  • Supplements (including multivitamin-minerals)
  • Medications

Lab tests of blood calcium are not an accurate tool to measure calcium nutritional status, as it is tightly regulated by the endocrine system and is rarely out of normal ranges.2

Most experts agree that calcium intake should be obtained mostly from food sources. Supplements can be used as an adjunct if the RDA of 1,000 milligrams is not exceeded. High daily intake of more than 1,000-1,500 milligrams of calcium supplements has been linked to greater incidences of heart attack,4,5 death by heart disease6 and fatal prostate cancer.7 An adequate dietary calcium intake from food (specifically dairy) may help protect the heart.4

Some foods in Canada have calcium added into them during production, such as calcium-fortified orange juice, soy beverages and other fortified milk alternatives. Consuming these fortified foods is essentially the same as taking supplements, although they may differ in bioavailability. Bioavailability is the proportion of calcium absorbed and used by the body from food relative to its content. Bioavailability of calcium is similar for most foods. Foods rich in dietary components such as oxalic acid, including spinach and sweet potatoes, and phytic acid, which is found in nuts, seeds and soy isolates, have more poorly absorbed calcium. This is not a hard and fast rule. For example, soybeans have highly bioavailable calcium. Eating a variety of calcium-rich food sources often is the best way to ensure you are meeting your needs.

Lastly, supplementation has shown to be just as effective as food in maintaining calcium balance. Bioavailability of calcium supplements generally improves if taken with a meal and at doses of 500 milligrams or less.2 There have not been any studies comparing calcium from food versus calcium-fortified foods with regards to bone health.

Some Common Food Sources

Source: Health Canada, Canadian Nutrient File (2015):

Other Considerations

Vitamin D – Discussing calcium adequacy cannot be done without also considering this nutrient, which is essential for the proper absorption of calcium in the gut.
Medications – Some medications such as antacids contain calcium, so be sure to check the label if you take these regularly. Calcium supplements may also reduce the effect of certain drugs8 such as thyroid medications, tetracycline antibiotics and iron supplementation for anemia. Multivitamins also commonly contain some calcium. If you choose to take calcium supplements, check with your health care provider to ensure your medications do not interact.
Supplement form – Calcium carbonate has a greater percentage of elemental calcium (the actual calcium we want) compared to calcium citrate, so less supplements need to be taken to make up the same amount of calcium. However, calcium carbonate, which can cause bloating or constipation, needs to be taken with a meal as it depends upon stomach acid for absorption.8 Conversely, calcium citrate can be taken on an empty stomach and has less reported side effects. It’s really a matter of preference and is something to discuss with your health care provider.

Bottom Line

Aim to get most of your calcium intake through a variety of calcium-rich food sources to meet the recommended average daily intake of 1,000 milligrams for men aged 19-50. Calcium supplements of 500 milligrams or less at one time can help fill gaps not met through food.


  1. Health Canada. 2014. Do Canadian Adults Meet Their Nutrient Requirements Through Food Intake Alone? Webpage: [accessed 15 Jan 2017].
  2. Institute of Medicine. 2011. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: The National Academies Press. doi:
  3. Osteoporosis Canada. 2017. Calcium: An Important Nutrient that Builds Stronger Bones. Webpage: [accessed 15 Jan 2017].
  4. Li K, Kaaks R, Linseisen J, Rohrmann S. Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition study (EPIC-Heidelberg). Heart (2012);98:920-925. doi:10.1136/heartjnl-2011-301345.
  5. Bolland MJ, Avenell A, Baron JA, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ (2010);341:c3691.
  6. Xiao Q, Murphy RA, Houston DK, et al. Dietary and supplemental calcium intake and cardiovascular disease mortality: The National Instituse of Health-AARP Diet and Health Study. JAMA Intern. Med. (2013);173: 639-646. doi:10.1001/jamainternmed.2013.3283.
  7. Giovannucci E, Liu Y, Stampfer MJ, Willett WC. A prospective study of calcium intake and incident and fatal prostate cancer. Cancer Epidemiol Biomarkers Prev (2006);15(2):203–10. doi: 10.1158/1055-9965.EPI-05-0586.
  8. National Institutes of Health Office of Dietary Supplements. 2016. Calcium Dietary Supplement Fact Sheet. Webpage: [accessed 1 Feb 2017].