• Calcium has an indispensable assistant in building bones: vitamin D. • Vitamin D helps the body absorb calcium. • Increasing vitamin D can help prevent osteoporosis. • A small amount of sun exposure can help the body manufacture its own vitamin D. • Five to 30 minutes of sunlight between 10 am and 3 pm twice a week to your face, arms, legs, or back without sunscreen will enable you to make enough of the vitamin • People with fair skin that burns easily should protect themselves from skin cancer by limiting sun exposure to 10 minutes or less. • Food and sun exposure should suffice, but if not, get 2,000 IU of vitamin D daily from a supplement.