Reader Question: I have osteoporosis. I am taking Actonel, Calcium and Vitamin D. I recently read that taking Vitamin C can help improve my bone density. Is this true? Can I stop my Actonel?
For the past few years there has been some discussion about Vitamin C and its role in bone metabolism and possible disease. Vitamin C acts as an antioxidant. It plays a major role in the formation of collagen and connective tissue.
The bone cycle is composed of osteoblasts that add bone and osteoclasts that remove bone. When the osteoclasts are more active, such as after menopause, bone density decreases and people can develop osteoporosis. It seems from studies that osteoporosis is related to excessive free radical formation. Free radicals are atoms, molecules or ions that are very reactive and are involved in chemical reactions. These radicals bring about oxidative stress (or excess of a chemical reaction called oxidation) that leads to cellular destruction. Oxidative stress may result in increased osteoclasts activity and therefore bring about excess bone removal. Vitamin C, an antioxidant, is thought to stop this free radical process and therefore stabilize the bone and possibly decrease one's risk of fracture.
Recently a group in Boston has been assisting us in answering the Vitamin C question. Shivani Sahni, a PhD student and Dr. Katherine Tucker from Tufts University have been using the 5,209 patient Framingham Heart Study cohorts to study this subject. In the October issue of the Journal of Nutrition, they published data showing that high vitamin C intake is associated with lower bone loss in elderly men. At the American Society for Bone and Mineral Research meeting, they produced an additional significant study on the topic.
In their study, they identified 958 people who answered a food frequency questionnaire and assessed their Vitamin C intake. They determined that those with both total as well supplemental Vitamin C had a significantly lower risk of a hip and nonvertebral fracture.
Interestingly, their results were not correlated with changes in bone density measurements. This is not completely surprising. We know that the quantity of bone is not the only factor involved in bone strength. The quality of the bone is important as well.
One must be careful to understand that this is not the best type of study. It is not a randomized double blind controlled study, which we use to prove that therapies work. The current information is obtained from a retrospective review (study looking back at data) and therefore any information that is obtained must be verified in a prospective (forward) monitoring study to see if these results are accurate. Unfortunately, with the negligible price of Vitamin C, it is questionable whether anyone will pay for an expensive study like this to prove these results.
In summary, one should be careful not to stop their medication based on studies such as these. While the results seem promising, one must understand the limitations in the data. Care should be taken to discuss this study as well as any others with your physician to decide on the proper therapy for you.