Pointers and pitfalls about calcium supplements

Many people take calcium for preventing osteoporosis, but who should take them, and how, remains a bit of a mystery.

No. Doctors often recommend calcium supplements to build stronger bones. But the benefits appear to be modest, so think twice before adding the pills to your daily regimen. Providing your body with a steady supply of calcium is essential for healthy bones. Yet debate persists over the benefits of taking supplements to strengthen bones and prevent fractures, largely because the results of studies have been inconsistent.

Yes. For most people, common antacids can be a cheaper alternative to calcium supplements.  In fact, the active ingredient in many popular antacid tablets (including Tums and Rolaids) is calcium carbonate — the same ingredient as in some calcium supplements. But not everyone who needs extra calcium can take advantage of the bargain, because calcium carbonate can cause side effects. They may be better off using supplements that contain calcium citrate which causes less side effects. Calcium citrate may also be a better choice for older people, whose stomachs produce less acid, which is necessary to absorb calcium.

Get the most from your calcium supplements by following these rules.

• Take calcium carbonate with a meal to ensure that it is well absorbed. (You can take calcium citrate anytime.)
• Don't take more than 500 milligrams of calcium at a time, since the body can't absorb more than that.
• When possible, avoid taking calcium supplements after eating a high-fibre meal, which may interfere with how well they are absorbed.
• Talk to your doctor if you take any drug that suppresses production of stomach acid, such as the H2 blocker ranitidine (Zantac) or the proton-pump inhibitor omeprazole (Prilosec). They may prevent your body from adequately absorbing calcium.

Calcium is a needed nutrient to shore up bones, but make sure you are taking supplements that will give you the most benefit. Following these guidelines will help.