A new Brazilian study suggests that post-menopausal women may benefit from vitamin-D supplementation to increase muscle strength and reduce frailty (1).
The study, conducted at Sao Paulo State University, found that older women given Vitamin D supplements were stronger and had fewer falls.
Menopause and Muscle
It is well known that going through menopause increases women's risk of bone loss, as a result of hormonal changes that influence bone health. However, many women are less aware of the effect of menopause on muscle strength.
During and after menopause, a decline in estrogen levels leads to a gradual and ongoing decrease in muscle mass, known as sarcopenia.
This type of muscle loss is a key health concern for post-menopausal women for several reasons. Post-menopausal muscle loss puts women at risk of frailty, falls and reduced mobility. It can reduce their independence and quality of life. Additionally, a reduction in muscle mass also leads to a lower metabolism, putting older women at risk of unwanted weight gain.
Vitamin D and Muscle Mass
Vitamin D is crucial for healthy muscle function. It acts on special receptors in muscle, helping to boost muscle mass and strength. Vitamin D also plays a role in protein synthesis and works with calcium and magnesium to enable more powerful muscle contractions.
Unfortunately many adults in the UK have low levels of vitamin D. In fact, 39% of adults have low vitamin D levels in the winter months, and older adults who spend more time indoors are particularly vulnerable to deficiency (2).
The double-blind trial tested the effects of vitamin D supplements versus placebo on the muscle strength and muscle mass of post-menopausal women. Muscle mass was estimated by the use of a total-body DXA (an X-ray scan), as well as tests of handgrip strength and fitness tests.
At the end of the 9-month study, the women receiving the vitamin D supplement showed a 25% increase in muscle strength, while the placebo group actually lost muscle mass. Over the 9 months, the women receiving the placebo supplements also had twice as many falls as those taking vitamin D.
"We concluded that the supplementation of Vitamin D alone provided significant protection against the occurrence of sarcopenia, which is a degenerative loss of skeletal muscle, says Dr. L.M. Cangussu, one of the lead authors of the study.
Supplementing Vitamin D - Dos and Don'ts
The ideal way to optimize vitamin D levels is through sensible sun exposure. This can be difficult in the winter months, and can be especially challenging for those with darker skin who have a harder time converting sunlight to vitamin D.
Current recommendations are that anybody over the age of 65 should be supplementing 10 micrograms (400IU) of vitamin D each day.
Vitamin D3 is widely considered to be a better form to take than synthetic D2. Taking vitmain D supplements alongside a fat-containing meal will also enhance absorption. Finally, many people prefer to take Vitamin D alongside vitamin K as these two vitamins work synergistically.
1. The North American Menopause Society (NAMS). "Vitamin D3 supplementation helps women build muscle even after menopause: New study demonstrates vitamin effectiveness in reducing degeneration and risk of falls." September 2015
2. NICE. Vitamin D: increasing supplement use in at-risk groups. November 2014. https://www.nice.org.uk/guidance/ph56 Accessed 30/10/2015.