If you are currently taking a biophosphonate such as Fosamax or Boniva, studies show that you should be consuming much more Vitamin D then previously thought. It seems that Vitamin D is critical in determining your reaction to biophosphonates. The study, presented at the Endocrine Society's yearly meeting, indicated that patients tested with a circulating vitamin D level greater than 33 nanograms (ng) per milliliter experienced a seven-fold increased likelihood of responding well to bisphosphonates. Today's typical vitamin D blood test measures 25-hydroxy vitamin D. The IOM says levels between 20 and 30 ng/ml are generally sufficient for normal, healthy adults. Meanwhile, the study revealed that 83 percent of those with vitamin D levels lower than 20 ng/ml experienced a poor response to bisphosphonates versus 77 percent with levels between 20 and 30 ng/ml, 42 percent with levels of 30 to 40 ng/ml, and 24 percent with levels higher than 40 ng/ml.
These "poor responses" that the study refers too are an increased risk for atypical femoral fractures that are both extremely painful and debilitating, and which are the subject of thousands of class action lawsuits around the country. Last year, the U.S. Food & Drug Administration (FDA) asked the manufacturers of bisphosphonates to add information to the "Warnings and Precautions" section of the drugs' labels describing the risk of atypical thigh fractures.
"There has been a lot of controversy over the correct vitamin D levels for people to have," said the lead study author, Dr. Richard Bockman, chief of the endocrine service at Hospital for Special Surgery in New York. "Vitamin D status should be optimized to improve outcomes in patients taking bisphosphonates," Dr. Bockman added.