Calcium and vitamin D are both essential for bone health. Current guidelines recommend that women age 51 and older and men age 71 and older need 1,200 mg of calcium a day, and men age 51 to 70 need 1,000 mg a day. Your body cannot make calcium. Ideally you should get calcium from the food you eat. Dairy products are the richest source. Youll get about 415 mg of calcium in 8 ounces of plain, low-fat yogurt, about 293 mg in 8 ounces of reduced-fat milk (2% milk fat) and about 307 mg in 1.5 ounces of cheddar cheese.