The daily recommendations for osteoporosis prevention are:
Take 1200-1500 mg of calcium in a divided dose. Your body can only absorb about 600 mg at one time, so it is best to take your supplement twice a day.
For example: 600 mg with breakfast and 600 mg with dinner.
Take your calcium supplement with a meal to increase the absorption of the calcium.
Take 800 IU of Vitamin D every day in a divided dose, with your calcium supplement. The Vitamin D helps your body absorb the calcium that you need. Most of the calcium supplements include Vitamin D, but if not, take 400 IU twice a day.
For example: Take your Vitamin D at the same time you take your calcium; 400 IU with breakfast and 400 IU with dinner.
Begin or continue weight bearing exercises to strengthen your bones.