Women taking birth control pills may need to keep an eye on their calcium intake, as researchers have discovered that oral contraceptives can decrease bone density. This is especially problematic, because the time during which it's most effective for women to optimize bone mass is adolescence and young adulthood -- a time when women are most-likely to use birth control.

It's feared that a decrease in bone density during these years can lead to osteoporosis later in life.

Subsequently, it's important that women who are using birth control -- especially those under 18 -- meet or exceeding the Recommended Daily Allowance for calcium. (The RDA for women age 9-18 is 1,300 milligrams a day, and is 1,000 milligrams a day for women age 19-50.)

Some calcium-rich foods that you might try include: milk (300 mg of calcium in 1 cup), yogurt (150-200 mg in 1 cup), pinto beans (140 mg in 1 cup) and almonds (80 mg in 1 cup).