Do You Really Need That Calcium Supplement? About 60 percent of postmenopausal women are thought to take calcium in pill form.
Possible Risks Calcium is a vital component of bones, and supplements offer a convenient way to get more of it. But while some research has indicated a benefit to calcium supplementation for older women especially, other data suggest that calcium supplements don't have any beneficial effect on osteoporosis and fractures, and that they may slightly increase the risk for heart attack, stroke, kidney stones, and gastrointestinal illness.
A recent study (Annals of Internal Medicine, April 9) analyzed existing data on more than 30,000 people to evaluate the association between dietary supplement use and death from all causes, cardiovascular disease, and cancer. The researchers assessed whether adequate or excess nutrient intake was associated with death, and whether intake from food versus supplement sources had any effect on the associations. The results suggested that supplementing calcium in excess of 1,000 milligrams (mg) per day was linked to a 53 percent increased risk of cancer-related mortality.
Digging Deeper Mone Zaidi, MD, PhD, professor of medicine, endocrinology, diabetes, and bone disease, has reservations about the study. "An important aspect of medication and/or supplement side effects is whether there is a mechanism," he explains. "Wearing my basic science hat, I don't see any possible mechanism through which calcium can cause gastrointestinal cancer. There is a maximum amount of calcium that is absorbable from the gut. High calcium intakes aren't necessarily fully absorbed, so any effect through systemic absorption seems unlikely." He adds that in a retrospective analysis of datasets it often is difficult to tease out confounding variables. "These results suggest a correlation--made in good faith on the basis of the best analysis of the clinical dataset--not causation," he concludes.
There are other caveats too. Because the study participants' supplement use was assessed at one point in time, their duration of use is unknown. Also, the prevalence and dosage of dietary supplement use was self-reported, and subject to recall bias. Plus, nearly 3,000 participants reported being diagnosed with cancer at some point, and it isn't clear whether they still had cancer during the study period or had a high risk of recurrence.
Who Should Supplement Calcium?
The U.S. Preventative Services Task Force (USPSTF) recommends against calcium supplementation for the primary prevention of fractures in postmenopausal women, but this recommendation doesn't apply to people with known osteoporosis and/or those who have already suffered an osteoporotic fracture. These individuals (along with people who consume a vegan diet, take corticosteroid drugs, or have a disease that impairs calcium absorption), will likely benefit from supplementing to ensure they meet the recommended daily amount for calcium (1,000 mg for ages 51 to 70, and 1,200 mg for age 71 and older). Even so, a study presented at the American Academy of Orthopaedic Surgeons annual meeting in March suggested that the majority of people with osteoporosis don't take adequate calcium supplementation to reduce their risk of osteoporosis-related fractures. The data also indicated that only 14 percent of osteoporosis patients with a previous hip fracture were adequately supplementing calcium.
Healthy Seniors Should Focus on Dietary Calcium Diet remains the best source of calcium and all other nutrients, with the exception of vitamin D. Vitamin D has few food sources apart from fortified milk, juice, and cereals; eggs; oily fish; cod liver oil; and flaxseeds--it is mainly synthesized in the skin with exposure to the sun. This means that people who live in regions that don't see year-round sunshine, or who are homebound, may be deficient in D. The vitamin is thought to play a role in bone health because it boosts the body's calcium absorption, so you may want to take a supplement.
For calcium, consume plenty of low-fat milk, yogurt, and cheese. If you avoid dairy, focus instead on fortified cereals and juices; dark leafy green vegetables; canned fish (eat the soft bones); and calcium-set tofu (tofu that has been coagulated using calcium sulfate). The bottom line? Eating plenty of calcium-rich foods is a sensible bone-strength strategy everybody should follow, but some seniors are still candidates for calcium supplementation. If you aren't sure about your bone health, discuss with your doctor whether you should get a bone density test--the USPSTF recommends testing for women age 65 and older, and younger women whose fracture risk is considered to be high. Also keep in mind that you also can help maintain your bone density through regular weight-bearing exercise, such as walking, jogging, climbing stairs, and lifting weights.
Caption Low-fat milk is loaded with bone-building calcium, but if you don't eat dairy, other calcium sources include fortified cereals and fruit juices, leafy green vegetables, legumes, canned fish, and endamame.
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|Publication:||Focus on Healthy Aging|
|Date:||Jul 24, 2019|
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