It depends. According to the Institute of Medicine, the amount of calcium per day varies per age and sex: Women 50 and younger: 1,000 mg per day, Men 70 and younger: 1,000 mg per day, Women over 50: 1,200 mg per day, and Men over 70: 1,200 mg per day. Children can also benefit from calcium, and the recommended calcium intake also varies per age: Younger than six months: 200 mg per day, 6 to 12 months: 260 mg per day, 1 to 3 years: 700 mg per day, 4 to 8 years: 1,000 mg per day, 9 to 18 years: 1,300 mg per day