According to Dr. Peter Green in his book Celiac Disease, A Hidden Epidemic, females in their early fifties should take 1,000 to 1,200 milligrams of calcium a day and males should take 800 to 1,200 milligrams of calcium a day. Younger, premenopausal women should take 1,000 milligrams of calcium a day. Dr. Green also recommends a ladder of vitamin D based on age. Women before menopause should take 200 International Units (IU) a day, women during menopause should up the amount to 400 IU a day, and women after menopause should increase to 600 IU a day. On the other hand, men, regardless of age, should take 400 IU a day.
Tip: Remember, vitamin D is important for proper absorption of calcium. Spread your calcium intake appropriately throughout the day. Your body can absorb no more than 500 to 600 milligrams in one dose, and it needs vitamin D to do it.