New research says that for women, Vitamin D deficiency can increase risk of hip fracture as much as 70%.

Hip fracture is one of the most common and most serious age-related health threats. There are about 1.6 million hip fractures worldwide each year, with 75% of the fractures happening to women over 50. Hip fracture leaves about 40% of its victims unable to walk independently, and can create profound loss of function.

In addition to causing chronic pain, reduced mobility, and increased dependence, hip fractures can actually be deadly. According to data from the International Osteoporosis Foundation, hip fracture increases the mortality rate as much as 24% in the first year, with a greater risk of dying for as long as five years after the fracture.

Known risk factors for hip fracture include low body weight, advanced age, and a diet that doesn't provide enough calcium. But new research is indicating that one of the most important of all risk factors is vitamin D deficiency, which could actually increase a woman's risk by an amazing 70%.

One of the latest studies, conducted by the University of Pittsburgh, monitored 800 women between the ages of 50 and 79 for nine years. The results showed that risk for hip fracture grew incrementally as blood levels of D vitamin dropped, to the point that women with the lowest levels of the vitamin had a 70% increased risk for hip fracture.

The association between low levels of the vitamin and hip fracture risk may be stronger for older women than younger women, the researchers noted. It is believed that vitamin D is tied most closely to hip fractures that occur because of pre-existing frailty, which is more commonly found among women over 50.

The recommended daily dose of vitamin D is 200 IU for people up to age 50, 400 IU for people aged 51 to 70, and 600 IU for people over age 70. Many experts disagree, citing this recommended dosage as far too low with some suggesting up to 1000 IU daily for both infants and adults.