Calcium supplements: how to take them?

Dear Ask The Doctor: How much calcium can body absorb at one time? a friend said body can only absorb 500mg at one time, so take 2 at different times in a day to make up the required 1000mg daily. Is that true?

Dear Mary: The recommended daily allowance (RDA) for Calcium depends on the age, then, for a female with age between 19-50 years old is: 1,000 mg/day. On the other hand, the tolerable upper intake levels (ULs) for calcium have been established for females with ages between 14-50 years old in: 2,500mg/day. If you stay between these ranges it is not likely that you have health risks from excessive Calcium intake.  Milk, yogurt, and cheese are rich sources of calcium; nondairy sources include vegetables, such as Chinese cabbage, kale, and broccoli, most grains do not have high amounts of calcium unless they are fortified, foods fortified with calcium include many fruit juices and drinks, tofu, and cereals. Most commonly used calcium supplements come as a carbonate form and should be taken during or immediately after meals. Approximately 500 milligrams of calcium can be taken at one time. If you and your doctor have agreed you need supplementation, be sure to take it three times a day or approximately one-third at a time. To avoid taking too much, do not take more than 2,500 milligrams per day. Remember that Vitamin D also is required for calcium absorption. The best source of vitamin D is sunshine for approximately 20 minutes per day.