Women might live longer if they get up to 1,000 milligrams (mg) of calcium a day from any combination of food and/or supplements, according to a study in The Journal of Clinical Endocrinology & Metabolism. The finding adds to a body of sometimes conflicting research on the risks and benefits of this bone-building mineral.

Bone health deteriorates with age, as bone cells break down faster than new ones are formed. Some autoimmune forms of arthritis, such as rheumatoid arthritis and lupus, also weaken bones due to the disease process as well as corticosteroids used to manage symptoms. (When taken in high doses or long-term, these powerful anti-inflammatories inhibit the body’s bone-building process.)

But while it’s especially important for older people and those with autoimmune arthritis to get sufficient calcium (and vitamin D, which helps the body absorb calcium), supplements have generated controversy. Two recent studies found that taking calcium supplements can increase the risk of heart attack and stroke, while other studies found no such link. 

This newest observational study analyzed data obtained from yearly questionnaires – filled out between 1995 and 2007 – from 9,033 Canadians as part of the Canadian Multicentre Osteoporosis Study. The average age of the participants at the start of the study was early to mid 60s, and most were women.

When researchers analyzed the variables – including calcium intake, source of calcium, vitamin D intake, as well as a patient’s overall health and age – they found that calcium intake among women was “more likely to be beneficial than harmful and that the same was true of calcium intake from dairy sources, nondairy sources, and supplements.”

They also found a statistically significant reduced risk of death among female supplement users who took up to 1,000 mg a day. Results were inconclusive for participants who took more than 1,000 mg a day.

In the United States, the recommended daily intake of calcium is 1,000 mg a day for adults up to age 50, and 1,200 mg per day for women older than 50 and for men older than 70. However, other studies suggest even less calcium – around 700 mg per day – is adequate for preventing fractures