Adult men and women need a daily calcium intake of about 1,000 to 1,200 mg, according to the National Academy of Sciences and the National Osteoporosis Foundation. To prevent loss of bone density, make sure to consume a diet high in low-fat dairy products and green leafy vegetables. Look for calcium that offers easy absorption. Chewable and liquid supplements absorb best. For best absorption, take no more than 500 mg of calcium at a time.
Testosterone drives muscle size, and that's a guy thing.
Women have a little, but not enough to become Arnold. Maybe you saw the photo in the paper recently of the Bulgarian woman squatting beneath a bar with well over 200 pounds on it. She was tiny, lean, athletic and feminine and far from the stereotype of weight-trained athletes. Many people also believe that if you are older, or suffer from chronic disease, you can't train with weights. Beginning in our mid-30s, we humans begin a shift.