Does Vitamin D supplementation decrease the risk of fractures?

When people think of reducing the risk of fractures, they automatically think of calcium supplementation. We’ve all heard of women in their 50’s and 60’s being told by their physician’s to start taking calcium to prevent bone mineral loss and to decrease the chance of developing osteoporosis. So why take vitamin D? There are two reasons for supplementing with vitamin D. First, a deficiency in vitamin D can lead to softening of the bones and second, vitamin D is essential for proper calcium absorption. In other words, you could be supplementing with calcium but not absorbing it properly. This is why many calcium supplements come with vitamin D.

How much vitamin D is enough to offset the risk of fractures? A recent publication in the New England Journal of Medicine set out to answer just this. They reviewed and analyzed data from 11 randomized studies of vitamin D supplementation in adults aged 65 and older and assessed hip and non-vertebral (not located in the spine) fractures. The findings from 31,022 people suggested that only a high intake of vitamin D (792–2000 IU/day) leads to a significant reduction in the risk of fracture. This reduction was approximately 30% for hip fractures and 14% for non-vertebral fractures. The authors also found that those who were most vulnerable i.e. those aged 85 and older and those with low baseline levels of vitamin D, had the greatest benefit from vitamin D supplementation. The most interesting part of the study was perhaps that a smaller amount of calcium supplementation (<1000 mg per day) with the highest intake level of vitamin D was more protective against fractures than a higher calcium intake.

This study highlights the need for taking calcium in conjunction with vitamin D. Further, it highlights the importance of taking high doses of vitamin D to actually reap the benefits of supplementation. Again, this is most beneficial for those who are at high risk for fractures i.e. it might not be beneficial for those without the risk factors of older age and low baseline vitamin D. Interestingly, vitamin D levels tend to be quite low among those living in Canada and other developed countries. One way to increase vitamin D is by getting natural sunlight as this synthesizes vitamin D in the body.

TAKE HOME MESSAGE: If you are at high risk for fractures, be sure to supplement your diet with vitamin D as well as calcium (please consult your physician first). Higher doses (approximately 800 IU/day) seem to be optimal for protection against fractures. After starting such supplementation, be sure to do some follow-up tests with your physician to ensure that you are taking the optimal dose of vitamin D. Another great way of ensuring you maintain bone mineral density is through weight bearing exercise, a topic I will cover in a future article.

Don’t let low bone mineral density become a problem in your life. Remember, you have control of your HALF!

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