Contrary to previous findings, a recent study suggests that vitamin D supplementation may not improve bone mineral density in adults.
The term "vitamin D" refers to several different forms of this vitamin. Two forms are important in humans: vitamin D2, which is made by plants, and vitamin D3, which is made by human skin when exposed to sunlight. Foods may be fortified with vitamin D2 or D3. The major role of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D helps the body absorb calcium, which forms and maintains strong bones. It is used alone or together with calcium to improve bone health and decrease fractures.
In a recent study, researchers conducted a comprehensive literature search for well-designed studies evaluating the effect of vitamin D supplementation on bone mineral density in adults without other metabolic bone diseases. Twenty-three studies evaluating 4082 participants, comprising 92 percent women with an average age of 59 years-old, were ultimately identified for inclusion.
In each included study, bone mineral density was measured in at least one of the following: lumbar spine, femoral neck, total hip, trochanter, total body or forearm. The researchers found that only six of the 23 included studies reported significant benefits of vitamin D supplementation on bone mineral density, while two actually reported significant loss of density. All other included studies reported a lack of benefit. Through analysis of data from all included studies as a whole, the researchers found that there may be a small benefit of supplementation in the density measurements of the femoral neck; however, beneficial effects at all other sites were lacking.
The authors concluded that the widespread use of vitamin D supplements for osteoporosis prevention in adults without vitamin D deficiency may not be beneficial. Additional well-designed clinical trials are needed to further evaluate these findings.
In addition to vitamin D and calcium, there is ongoing research evaluating the potential benefits of many other integrative therapies on bone density. Evidence suggests that higher dehydroepiandrosterone (DHEA) levels may be linked to higher bone density, particularly in women who have undergone menopause. Research reports that DHEA supplements may help increase bone density. Additionally, clinical studies have found that strontium ranelate may prevent bone loss, increase bone strength, and reduce fractures in postmenopausal women. Evidence suggests that treatment compliance may further reduce the risk of hip fractures.
For more information about integrative therapies for bone density, please visit Natural Standard's Comparative Effectiveness Database.
For more information about vitamin D, please visit Natural Standard's Foods, Herbs & Supplements Database.