Q. Shall I start taking extra calcium? What about coral calcium?

A. Most Americans get only half the calcium they need from their diet. If you don't eat enough dairy products, broccoli, almonds and tofu, you'll need calcium and vitamin D supplements. Not only does vitamin D help you absorb calcium, but a study of 1,179 healthy women over age 55 by Joan Lappe and others found that 1,100 IU of vitamin D3 plus 1,400 mg of calcium a day decreased cancers by 60 percent. And in an amazing 2007 meta-analysis, Drs. Philippe Autier and Sara Gandini found that older folks taking 400 to 800 IU of vitamin D lived longer. See my Jan. 8 article to see why.

In another 2007 meta-analysis, Dr. Benjamin Tang and others found that taking 1,200 mg or more of calcium reduced fractures by 12 percent. You start to lose bone mass after age 30. At menopause, bone and calcium loss from the spine and hip doubles to 2 percent a year, weakening your bones and leading to painful hunchback with loss of height as well as hip fractures. Those ages 9 to 18 need 1,300 mg a day of calcium, 1,000 mg from ages 19 to 50, and 1,200 mg a day for those above age 50, along with vitamin D: 400 to 800 IUf a day for adults under age 50 and 800 to 1,000 IU a day over age 50.

I'd recommend a bone density scan in women ages 60 to 64 who weigh under 145 pounds and in all women age 65 and older. If it shows thin bones, get a vitamin D level and ask about drugs like Fosamax, Reclast and Actonel, as vitamin D and calcium aren't good enough. Don't be scared about osteonecrosis, or death of the jaw bone, as this is a rare complication mostly seen in folks with cancer who receive such drugs via IV through the veins. Evista, another drug, may not reduce hip fractures.

Okinawans live long lives and take coral calcium, but they also eat lots of vegetables, grains and fish and are physically active, so it has never been proven that coral calcium is superior. Okinawa coral may also have too much lead and mercury. Bone meal, dolomite and perhaps oyster shell calcium may likewise contain excess lead. Calcium carbonate such as Tums needs to be taken with meals and may not be absorbed in folks with low acidity, like the elderly or those on acid-lowering pills or who had gastric bypass. So calcium citrate is the best — look at elemental calcium rather than the tablet strength to see if you're getting enough.