Newswise — Sixty-year-old Darlene Yates has had two hip replacements, a knee replacement and this past year shattered her left femur while she was walking in her neighborhood. Her diagnosis seemed obvious -- osteoporosis. But it turns out she had bone weakness caused by a vitamin D deficiency.

“I thought with my age and all my broken bones that I definitely had osteoporosis ,” Yates said. “The low vitamin D levels really took me by surprise.”

Vitamin D promotes the absorption of calcium and phosphorus. It regulates how much calcium remains in the blood and how much makes its way to the bones and teeth. It also has been found to reduce the risk of breast cancer, colon cancer and ovarian cancer. Vitamin D deficiency contributes to osteoporosis by reducing calcium absorption and osteoporosis is an example of the long-term effects of vitamin D deficiency.

In a recent review of women with osteoporosis hospitalized for hip fractures, 50 percent were found to have signs of vitamin D deficiency. Low levels are most often seen in older women; however, times appear to be changing.

“I am seeing many active, young women and men who have dangerously low vitamin D levels,” said Dr. Kenneth Mathis, chairman of orthopedic surgery with The Methodist Center for Orthopedic Surgery. “I believe if these people begin taking the daily recommended amount of vitamin D when they are younger, and get their levels tested regularly, that they might be able to prevent osteoporosis and certain cancers when they get older.”

Sources of vitamin D include fortified milk, cod liver oil, fish such as sardines, tuna, salmon and mackerel, some yogurt and breakfast cereals, and the sun. However, if you wear an SPF of eight or more, you will have a tough time converting the sunlight into vitamin D.

Most adults over age 50 need to take a daily supplement of vitamin D if they don’t think they are getting the daily recommended amount. Adults under age 50, including pregnant women, need 200 IU of vitamin D daily. A person over age 50 needs 400 IU daily and it goes up to over 600 IU at age 70.

Mathis says taking the correct amount is important because too much vitamin D can be toxic. Vitamin D is stored in the liver and in the fat tissue. When you take too much it cannot leave the body as easily as water soluble vitamins such as vitamin C. The excess vitamin D can lead to too much calcium in the blood, which can cause kidney stones and/or kidney failure.

Yates has begun a strict vitamin D regimen to build up her levels. She says she has more energy than she ever has and is feeling better.

“I’m hoping that I can get to where I don’t break any more bones and have to have any more surgeries,” Yates said. “If I would have known about the link between vitamin D and bone weakness 40 years ago, you can bet I would have done something about it.”