New research published in Nature Medicine casts a disturbing light on vitamin E supplements, which the researchers say have been shown to cause bone loss, at least in rodents. If this discovery is found to be true in humans as well—and studies have not yet been done to make this determination—it could have a significant impact on how we use vitamin E supplements.
The form of vitamin E used in the study was alpha-tocopherol, the most common type of the nutrient and the one most often found in supplements.
It should be noted, however, that another form of vitamin E, gamma-tocopherol, has been found in a growing number of studies to have an important role in managing prostate cancer, and that a new study in postmenopausal women suggests it may help with bone formation.
In the Nature Medicine study, the researchers noted that adding vitamin E (alpha-tocopherol) at doses equivalent to those taken by humans to the diets of mice and rats that had normal levels of vitamin E resulted in a 20% reduction in bone mass after 8 weeks. The same effect did not occur when the animals were given delta-tocopherol, a finding that suggests the effect had nothing to do with the vitamin’s antioxidant properties.
Fujita K et al. Vitamin E decreases bone mass by stimulating osteoclast fusion. Nature Medicine 2012; 18: 589-94
Hamidi MS et al. Effects of vitamin E on bone turnover markers among US postmenopausal women. Journal of Bone Mineral Research 2012 Jun; 27(6): 1368-80