A new study published in the journal JAMA Internal Medicine suggests that vitamin D supplementation may not be as beneficial for postmenopausal women as once thought.
Vitamin D is essential for regulating the absorption of calcium and phosphorus, and for maintaining strong, healthy bones—this is why people who are lacking in vitamin D are more prone to osteoporosis. Research has shown that almost half of all postmenopausal women suffer from an osteoporosis-related fracture due to reduced estrogen levels—a contributing factor for the development of osteoporosis. This suggests that improving bone health with the use of vitamin D supplements may be especially important for postmenopausal women.
To test this theory, researchers from the University of Wisconsin School of Medicine and Public Health recruited over 200 postmenopausal women who also had an insufficiency of vitamin D (between 14 and 27 ng/ml). Participants were randomly divided into three groups—one group received a higher dose of vitamin D, another received a low dose, and the last group received a placebo.
Over the course of one year, researchers monitored each woman’s calcium absorption, muscle mass, bone mineral density, and results from sit-to-stand tests. There was a slight difference in calcium absorption between the groups—a one percent increase in the high-dose group versus a two percent decrease in the low-dose group and 1.3% decrease in the placebo group. However, researchers discovered there were no overall benefits—they found no difference in changes to bone density, muscle mass, or results from sit-to-stand tests between the groups. Furthermore, the range in vitamin D supplementation did not affect the number of falls among participants or the amount of physical activity they did.
It’s important to note that while vitamin D may not be as effective as once thought for postmenopausal women (more large-scale studies still need to be done), it’s still an essential vitamin that plays a key role in many other functions.
Sources for Today’s Article:
Hansen, K.E., et al., “Treatment of Vitamin D Insufficiency in Postmenopausal Women: A Randomized Clinical Trial,” JAMA Internal Medicine 2015; doi: 10.100/jamainternmed.2015.3874.
McIntosh, J., “High-dose vitamin D supplements ‘do not improve bone health’ for postmenopausal women,” Medical News Today web site, August 4, 2015; http://www.medicalnewstoday.com/articles/297651.php.