A pair of studies released independently this week underscores the importance of vitamin D in keeping bones healthy and lengthening lifespan.
A study to be published in the April issue of the Journal of Clinical Endocrinology and Metabolism, for instance, found that vitamin D deficiency was linked to a higher mortality rate among elderly women living in nursing homes in Austria.
Of all age groups, deficiency in the sunshine vitamin is highest among the elderly, who are often sedentary and get little sun.
For their study, Austrian researchers followed 960 nursing home residents who averaged about 84 years of age.
After a little more than two years, 30 percent of the participants died, 93 percent of whom were below recommended levels of vitamin D. The finding has prompted scientists to recommend treating seniors with up to 800 IUs of supplementary vitamin D.
Deficiency has also been identified in previous studies as a causal risk factor for skeletal diseases in the elderly. But another study released this week from the Archives of Pediatrics & Adolescent Medicine points out that vitamin D intake can also help lower the risk of developing stress fractures in preadolescent and adolescent girls.
After following about 6,700 preadolescent girls for seven years, US researchers found that vitamin D intake was more important for preventing stress fractures than calcium, particularly among girls who engaged in high-impact activities for at least one hour a day.
"...there was no evidence that calcium and dairy intakes were protective against developing a stress fracture or that soda intake was predictive of an increased risk of stress fracture or confounded the association between dairy, calcium or vitamin D intakes and fracture risk," the authors wrote.
While the body is able to store vitamin D from the sunny summer months, food sources include cheese, mackerel, sardines, salmon and fish liver oil.