There was less of a problem with decaffeinated cola, but the findings were similar for diet soft drinks. The researchers didn't find an association between cola drinking and lower bone mass in men.
Results of the study were published recently in the American Journal of Clinical Nutrition.
"Moderation is really important. If you really like soft drinks, you don't need to take them out of your diet completely, but limit yourself to one or two glasses" a week, Kaur said.
And, she added, make sure you're getting enough calcium and vitamin D to protect your bone health. Vitamin D needs vary by age, and where you live, so check with your doctor to find out how much vitamin D you should be consuming each day. Kaur said that if you're not getting at least 1,000 to 1,200 milligrams of calcium daily from your diet, you should take a calcium supplement to ensure you're getting adequate amounts of the mineral.
Another important way to prevent osteoporosis, according to Raisz, is to exercise.
"The standard recommendation is a half an hour a day for adults and an hour a day for kids, but anything is better than nothing," he said. "Try to walk at least a half a mile a day, and engage in a weight-bearing exercise of some sort."
More information
To learn more about risk factors for osteoporosis, visit the National Osteoporosis Foundation.
