By Eduardo Gonzales, MD
Is it advisable to take calcium supplements to prevent osteoporosis? What other health benefits does calcium supplementation have? What about adverse effects? I am 52 years old and had my menopause a year ago.—firstname.lastname@example.org
It is indeed important that we take in enough calcium every day because this mineral is needed to build new bones and maintain bone strength. It is also needed to maintain heart rhythm, and muscle and nerve functions.
How much calcium do we need and where should we source it?
The recommended daily dietary allowances (RDA) for calcium among adults are as follows: Men 19 to 70 years old (1,000 mg), 71 years old and older (1,200 mg); Women 19 to 50 years old (1,000 mg), 51 years old and older (1,200 mg).
We should source our calcium requirements through our diet. A balanced diet that is rich in calcium and vitamin D (which helps the body absorb calcium) is usually sufficient to give us our daily calcium requirement. Good sources of calcium include dairy products such as milk, yogurt, cheese, and ice cream; dark green leafy vegetables; fish with soft bones that can be eaten such as sardines and salmon; and soya beans.
Who should take calcium supplements?
Calcium supplements are unnecessary or even harmful for most people. They are an option only for certain groups of individuals: those whose diet is likely to be inadequate in calcium like vegans and lactose intolerant people; those who have certain digestive diseases such as inflammatory bowel disease and celiac disease; and those who are at risk of calcium deficiency such as people who consume a large amount of proteins, which force the body to excrete a lot of calcium, and the elderly, especially postmenopausal women.
Calcium deficiency in middle-aged and elderly people can lead to osteoporosis, the progressive loss of bone mass that occurs with age. Osteoporosis, which affects women four times more often than men, results in weakened bones that break (fracture) or collapse with very little force or even spontaneously. Postmenopausal women are at highest risk for osteoporosis because they lose bone mass fast since their ovaries have stopped producing the female hormone estrogen that helps deposit calcium in bones.
Other possible health benefits of calcium supplements
Some studies suggest that calcium, along with vitamin D, may have benefits beyond bone health such as reducing the risk for colorectal, breast and ovarian cancers, and protecting against diabetes and high blood pressure. But evidence about these health benefits is not definitive.
How much calcium supplements should postmenopausal women take?
There is no standard recommendation on how much calcium supplements postmenopausal women should take. Certainly, it should not be more than the safe limit, which is 2,000 mg per day for people 51 years old and above.
Adverse effects of too much calcium
There is compelling evidence that there may be a link between too much calcium and atherosclerosis and heart disease. A similar link possibly exists between calcium and prostate cancer.
Calcium also interacts or interferes with the absorption of many drugs and some minerals like iron and zinc. Hence, if you are taking any maintenance medication clear this matter up with your doctor.
The good news though is that the adverse effects of calcium are seen only in supplements. Evidently, dietary calcium is essentially safe. Hence, it is best that people, especially the middle-aged and elderly derive their calcium needs from food sources. And until more is known about their possible risks, we should all take it easy on those calcium supplements.
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