Timing matters: When to take calcium supplements

In general, you can take calcium supplements at any time of day. But there are special circumstances that may affect when you should take calcium supplements.

• Dosage. Calcium is absorbed most efficiently when it's taken in amounts of 500 or 600 mg or less at one time. So if you take 1,000 mg of calcium a day, split it into two or more doses over the course of the day.
• Other supplements. Calcium can affect or be affected by other supplements. If you also take an iron supplement, for instance, don't take it at the same time as you take calcium. Check with your doctor, pharmacist or dietitian about other interactions.
• Medications. If you take prescription medications, ask your doctor or pharmacist about possible interactions with calcium supplements. You may need to take calcium supplements several hours before or after taking your medications.
• Meals and snacks. If your calcium supplements contain calcium carbonate, take them with food. The stomach acid produced when you eat helps the absorption of calcium carbonate. If your calcium supplements contain calcium citrate, you can take them with or without food.

If you're still not sure about the best time to take your calcium supplements, check with your doctor or pharmacist for guidance.