The best way to get any mineral is through your food intake, but most women cannot get enough calcium by diet alone. There are several types of calcium supplements, but the two main types have either calcium carbonate or calcium citrate.
Calcium carbonate is more likely to cause bloating, constipation, and other symptoms, since the carbonate part can result in bloating similar to drinking lots of carbonated beverages. Calcium citrate causes less bloating and may be a better option if you find carbonate causes stomach cramping or other unwelcome gastrointestinal effects.
The best option for calcium supplementation is actually calcium capsules that also have vitamin D -- many women can use the additional vitamin D to improve calcium absorption.
Your body can absorb only 500 to 600 milligrams of calcium at a time, so take calcium throughout the day. If all you do is take several tablets once a day, you waste the supplement and delude yourself that you're getting your recommended daily requirement.
Phosphorus in carbonated drinks was once thought to prevent the body from absorbing calcium out of calcium-fortified products. However, further studies showed differently. The real culprit was that sodas were being consumed in place of calcium-fortified drinks like milk. Each American consumed 56 gallons of soda in 1998, while the average consumption of milk was only 24 gallons per person.