Tums provide calcium as calcium carbonate (chalk), which is not always easily absorbed by the body. I recommend using calcium citrate, a form that is better absorbed.
Because Tums are less expensive than calcium supplements, you may prefer to risk the absorption problem in order to keep your costs down. This is less of a concern for younger people. But as you age, the amount of acid in the stomach decreases, and acid is necessary for absorption of calcium carbonate. You'll need to take three Tums tablets per day to get 600 mg of elemental calcium.
As you may know, I recently revised my calcium recommendation downward. I made the change after reviewing two large studies conducted by the Harvard School of Public Health, which showed that calcium doesn't actually reduce the risk of osteoporosis as we once thought. I now suggest that women supplement with only 500 to 700 mg of calcium citrate in two divided doses taken with meals, for a total daily intake of 1,000-1,200 mg from all sources. You may want to reduce your supplemental calcium if you ingest high amounts of dietary calcium, such as dairy products such as milk, cheese, cottage cheese and yogurt along with other calcium fortified foods like tofu, soy milk and orange juice. In the past, I recommended supplementing with 1,200 mg daily in divided doses and 1,500 mg for postmenopausal women who were not on hormone replacement therapy.
Men need even less calcium. I now recommend 500 mg from all dietary sources and suggest that men avoid taking any supplemental calcium. High intake of this mineral is associated with an increased risk of prostate cancer. One of the Harvard studies found that men who drank two glasses of milk a day (that translates to about 1,000-1,200 mg of calcium) had twice the incidence of developing advanced prostate cancer.
The lower amounts of calcium I now recommend should be sufficient to protect bones. However, the lifestyle measures listed below can also help prevent bone loss as you get older (after age 30 both men and women begin losing bone mass slowly; this accelerates for women after menopause):
- Exercise regularly. Make sure to engage in both weight-bearing exercise (walking, jogging or anything else you can do on your feet) and strength training for muscles.
- Be sure to get adequate vitamin D. I now recommend 2,000 IU of vitamin D3 daily. The ultraviolet B rays of the sun trigger your skin to make vitamin D (provided you're not wearing sunscreen). We don't get much D in our diets, so if you don't get regular sun exposure, it is necessary to supplement with this vitamin.
- Get adequate daily vitamin K (120 mcg for men, 90 mcg for women). Low intake has been linked to low bone density. You get vitamin K in broccoli, Brussels sprouts, dark green lettuce, collard greens and kale.
- Watch your protein intake. Too much can promote calcium loss from bones.
- Take supplemental vitamin A only in the form of beta carotene, as part of a mixed carotenoid product. Preformed vitamin A (identified on vitamin labels as "retinol" or "vitamin A palmitate") can weaken bones.
- Cut back on caffeine and sodas: too much of either can promote calcium excretion.
Andrew Weil, M.D.