For the best response to bisphosphonate treatment for osteoporosis, women need to have vitamin D levels higher than those recommended by the Institute of Medicine, according to new research.
Researchers from Weill Cornell Medical College found that women who have low bone density are seven times more likely to respond to bisphosphonates -- the standard therapy for osteoporosis -- if their vitamin D levels are higher than the levels recommended by the Institute of Medicine. The research was presented last week at a meeting of the Endocrine Society.
The Institute of Medicine released its vitamin D intake recommendations last November, saying that most adults ages 70 and younger don't need any more than 600 International Units (IUs) a day to maintain proper bone health (adults older than age 70 should get at least 800 IUs a day). This level of vitamin D intake -- in addition to adequate calcium intake -- is recommended to maintain the minimum vitamin D level of 20 nanograms of vitamin D per milliliter of blood that is needed to maintain good bone health, according to the National Institutes of Health.
However, Dr. Richard Bockman, M.D., Ph.D., professor of medicine at Weill Cornell, found in his study of 160 postmenopausal women with osteoporosis that those who had an average vitamin D blood level of 30 nanograms per milliliter -- higher than the recommended level -- were not likely to respond to at least 18 months of treatment with bisphosphonates.
But when women had blood vitamin D levels of 33 nanograms per milliter, they were seven times more likely to respond to the bisphosphonate treatment than women with lower levels of vitamin D, according to the research.
"This value of at least 33 nanograms per milliliter is higher than the level considered as 'adequate' by the Institute of Medicine report for the general population and most likely requires a vitamin D intake higher than 600 IU for this therapeutic outcome," Bockman said in a press release. "In the future, I think we're going to see vitamin D recommendations based on specific conditions."
Calcium is important for proper functioning of the heart, muscles and nerves. The body needs to have adequate vitamin D in order to absorb calcium, according to the National Institutes of Health. Without enough vitamin D, the body has to use the calcium stores in the skeleton, which weakens the bones.
Few foods naturally contain vitamin D; people can get vitamin D from foods like egg yolks, liver, fortified milk and saltwater fish, according to the National Institutes of Health. Vitamin D can also be obtained from sunlight, when ultraviolet rays hit the skin to trigger the production of vitamin D.
Dietary supplements are another way to increase vitamin D intake, but supplements shouldn't be considered a substitute for a healthy diet that includes foods with vitamin D, the National Institutes of Health said.
For more on how vitamin D helps fight osteoporosis, WATCH: