What Could Sodium Mean for the Bones?

Bone fracture risk linked to high sodium intake among postmenopausal women

(RxWiki News) As women grow older, they are often at greater risk for osteoporosis and bone fractures. Their diets may also play a part in their risk of bone fracture.

A recent study found that having a very high salt intake was linked to a higher risk for bone fractures in women past menopause.

Women in the top 25 percent for sodium intake were four times more likely to have bone fractures than women who had lower sodium intakes.

This risk existed even after taking into account women's risk for osteoporosis and other factors.

"Reduce salt in your diet."

The study, led by Mika Yamauchi, a professor of health and nutrition at the Shimane University Faculty of Medicine in Japan, looked for a possible relationship between the risk of bone fracture and sodium intake.

The researchers assessed 213 healthy women, average age 63, who were past menopause and had been screened for osteoporosis.

The researchers measured their calcium levels, potassium levels, and vitamin D levels, as well as levels of several other nutrients.

They also assessed their bone mineral density and bone metabolic markers, which are both related to risk of osteoporosis.

Based on a questionnaire about how frequently they ate certain foods, the researchers estimated the women's intake of protein, calcium, magnesium, potassium, sodium, vitamin D and vitamin K.

The women also underwent a motor skills test during which they stood on one foot with their eyes closed and the strength of their grip was assessed.

A doctor assessed each woman for non-vertebral fractures. A non-vertebral fracture is a fracture anywhere on the skeleton besides the spine.

The average sodium intake among all the women was 5,211 milligrams a day. The women in the top 25 percent for sodium intake averaged 7,561 milligrams a day.

The researchers did not find sodium intake linked to bone mineral density or bone metabolic markers. It also wasn't linked to their muscle strength or balance.

However, the women in the top 25 percent for sodium intake were about four times more likely to have a bone fracture than the women who consumed lower amounts of sodium.

This result remained even when the researchers had accounted for other risk factors for fracture, including the woman's age, weight, bone mineral density, calcium and vitamin D intake, blood levels of vitamin D, balance and muscle strength.

The recommended daily intake of sodium is 2,300 milligrams, which is equivalent to less than one teaspoon of salt.

This study was presented at a conference, so it has not yet undergone peer review by other researchers. These findings should be considered preliminary.

The study was presented June 15 at The Endocrine Society's 95th Annual Meeting in San Francisco. The authors reported no conflicts of interest. Funding information was unavailable.

Review Date: 
June 24, 2013