At the age of 55, Carol Jane Carlson was more active than many people half her age. An outdoor enthusiast, she enjoyed hiking, downhill skiing, gardening and running. She had completed seven marathons, with plans for more. As a nurse, Carol understood the importance of exercising, eating a nutritious diet and maintaining a healthy weight. Yet, one important detail literally tripped her up.

One day, Carol stumbled over a raised area of pavement in a parking lot and fractured her upper right leg bone (femur). The fracture healed, but Carol's right leg remained stiff and weak. This disability led to severe restrictions in both her professional and personal life. Carol's work as a surgical nurse required her to spend hours assisting physicians in the operating room, but after her accident she was unable to stand for more than four hours at a time. She was also advised to stop participating in her favorite sports--running, skiing and hiking.

Luckily, orthopaedic surgery on Carol's leg restored her mobility. She also learned that the severity of her fracture had been caused by a deficiency of Vitamin D. Though many people are aware of the connection between calcium and osteoporosis, fewer people are aware that Vitamin D is as necessary for good bone health as calcium and regular exercise. Without Vitamin D, calcium cannot be absorbed or reabsorbed into the bloodstream. Low levels of Vitamin D are associated with increased risk of osteoporosis, bone loss and fractures.

Although sunlight is the primary source of Vitamin D, the ability to process it through the skin diminishes with aging. National studies have estimated that 70 percent of women between ages 51 and 70, and 90 percent of women over age 70, do not get adequate Vitamin D. Although Vitamin D can also be obtained from food sources and supplements, many people are unaware of the correct requirements or don't follow them.

Though Carol knew the importance of calcium supplements and Vitamin D, she didn't realize that she wasn't always getting the right amounts. To help others avoid Carol's problem, people need to be educated about Vitamin D and effective screening tests must be developed to recognize deficiencies before the bones are affected. Preventing and detecting vitamin deficiencies as early as possible will help prevent fractures, lower health care costs and avoid life-altering disabilities.