1 Visual acuity (sharpness) tests help your doctor find out if you have a problem that affects how well you can see. 2  They measure the eye's ability to see details at near and far distances. 3  The tests usually involve reading letters or looking at symbols of different sizes on an eye chart.
Amount of calcium. Elemental calcium is key because it's the actual amount of calcium in the supplement. It's what your body absorbs for bone growth and other health benefits. The Supplement Facts label on calcium supplements is helpful in determining how much calcium is in one serving.
In addition to vitamin D, vitamin C, vitamin E, vitamin K, magnesium, and boron assist in absorbing calcium and also increasing bone mass. Exercise also helps the body absorb calcium.