Are Calcium Supplements Safe?
added 05/31/11
by Mary Saucier Choate, M.S., R.D., L.D.
Dietitian and Co-op Food and Nutrition Educator
Lots of people are concerned about what to do after hearing recent news reports of a possible link between calcium supplements and increased risk of heart attack, stroke, or other cardiovascular diseases.
It is important to remember that when you look at all of the studies on calcium supplementation, that most of the evidence does not support a link between calcium and cardiovascular disease risk. This is where it really helps to consult health organizations that can help to sift through the science and put it into perspective.
For example, the American Society for Bone and Mineral Research produced a helpful statement about the risks after reviewing the studies. They report that while “some analyses have suggested a possible increase in risk …others have not provided evidence of increased risk. Until further studies are done and more information is available, they advise that anyone taking or considering taking calcium supplements be aware of the following key points:
1. There are numerous large studies of calcium plus vitamin D that have shown no increased risk of cardiovascular events.
2. Persons currently taking calcium supplements should not necessarily discontinue their use. Rather, they should discuss the decision to use these agents with their health provider, and understand that food remains the best source of calcium. Supplements should be used only when adequate dietary intake of calcium cannot be achieved.
3. The beneficial effects of calcium are found with relatively low doses. More is not necessarily better. Individuals should discuss the amount of their calcium intake with their health provider.
4. In almost every modern study of osteoporosis treatment, adequate calcium and vitamin D were required for medications to have anti-fracture efficacy.
5. Elderly individuals and others with impaired renal (kidney) function who take calcium supplements may be at higher risk of cardiovascular problems.
It is important to look not just at the individual study, but at the totality of studies on the topic. Science builds on what we know already. One study adds to the knowledge, but must be put into perspective with all that we’ve learned so far. For example, according to the Office of Dietary Supplements Calcium Fact Sheet: in the Women’s Health Initiative [study], supplementation with both calcium (1,000 mg/day) and vitamin D (400 IU/day) did not significantly increase the risk of [heart attack] in postmenopausal women. And a 2010 systematic review of 17 prospective studies and randomized trials found no increased risk of cardiovascular disease from calcium supplements with or without vitamin D among adults.
So what to do?
The main points to remember are that as with all supplements, more is not necessarily better. The safest path would be to aim for getting all of your calcium from foods and beverages and if that is not possible, then taking a supplement.
Like every dietary supplement, before taking calcium, consumers should look at what they are already eating to see if they are getting enough calcium. Of course, dairy products such as milk, yogurt, and cheese provide good sources of calcium. Calcium-fortified foods such as orange juice, bread, cereals, and sport bars among other fortified foods can also help to fill the calcium gap. If you are not able to eat enough calcium–rich foods, you may need to consider a supplement.
Your daily calcium intake total from food alone or food and supplements should add up to the recommended daily calcium amount:
Institute of Medicine’s Recommended Daily Calcium Intake
| Age | Male | Female | Pregnant | Lactating |
| 0–6 months | 200 mg | 200 mg | ||
| 7–12 months | 260 mg | 260 mg | ||
| 1–3 years | 700 mg | 700 mg | ||
| 4–8 years | 1,000 mg | 1,000 mg | ||
| 9–13 years | 1,300 mg | 1,300 mg | ||
| 14–18 years | 1,300 mg | 1,300 mg | 1,300 mg | 1,300 mg |
| 19–50 years | 1,000 mg | 1,000 mg | 1,000 mg | 1,000 mg |
| 51–70 years | 1,000 mg | 1,200 mg | ||
| 71+ years | 1,200 mg | 1,200 mg |
Too much calcium from supplements can cause unwanted side effects such as kidney stones and harmful calcium deposits in blood vessels. Keeping your total calcium intake below the level known to cause these side effects is important. Excessively high intakes are more likely to be caused by using high doses of calcium supplements. It is rare to get too much calcium from foods
Tolerable Upper Intake Levels for Calcium
| Age | Male | Female | Pregnant | Lactating |
| 0–6 months | 1,000 mg | 1,000 mg | ||
| 7–12 months | 1,500 mg | 1,500 mg | ||
| 1–8 years | 2,500 mg | 2,500 mg | ||
| 9–18 years | 3,000 mg | 3,000 mg | 3,000 mg | 3,000 mg |
| 19–50 years | 2,500 mg | 2,500 mg | 2,500 mg | 2,500 mg |
| 51+ years | 2,000 mg | 2,000 mg |
Additional options for keeping your bones strong beyond getting enough calcium:
- Weight-bearing activities, such as walking, running, tennis, dancing, hiking, as well as weight training (with weights, machines, exercise bands, soup cans or water jugs, for that matter) stress bones (in a good way) and promote their growth.
- Getting adequate amounts of vitamin D, from sun and supplements, is also good for bones. (For cancer and wrinkle protection– no more than 10 to 15 minutes of sunshine on face arms and legs without sunscreen, and/or 600 to up 800 IU of a vitamin D supplement. The daily upper intake level shown to be safe for vitamin D supplements is 4000 IU.
For More Information
- The American Society for Bone and Mineral Research. Type “calcium supplements” in the search box.
- Dietary Supplement Fact Sheet: Calcium
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