Low intake of vitamin K may increase risk of hip fracture

Adequate intake of vitamin K1, but not K2, may reduce the risk of suffering a hip fracture, suggests a new study from Norway.

In the observational trial, the incidence of hospitalizations due to hip fractures was measured in 1569 men and 1238 women between the ages of 71–75 from 1997 to 2009 (1). In addition, vitamin K1 and K2 intake data were collected at the beginning of the study. The results showed that the participants with the lowest vitamin K1 intake, when compared to those with the highest K1 intake, had an increased risk of suffering a hip fracture. Vitamin K2 intake was not associated with hip fractures.

The researchers concluded that a low intake of vitamin K1, but not K2, may be associated with an increased risk of hip fractures. Intakes of vitamin K2 were mainly through consumption of milk, cheese and other dairy products (50%), meat (24%) and eggs (13%), while K1 intakes were through vegetables, fruits and berries (70%). This would suggest that a high consumption of vitamin K1 may represent a healthy lifestyle, while a diet high in vitamin K2 may not.

There is conflicting evidence on whether dietary or supplementary vitamin K has a preventive effect on osteoporosis and fracture risk. Some studies have suggested an association between low dietary vitamin K1 and fracture risk (2, 3), whereas others have not (4). Most studies in favor of vitamin K as treatment for osteoporosis and prevention of fractures have investigated vitamin K in pharmacological doses.

1. Apalset E. M. et al. Intake of vitamin K1 and K2 and risk of hip fractures: The Hordaland Health Study. Bone. Online publication September 2011.
2. Booth S. L. et al. Dietary vitamin K intakes are associated with hip fracture but not with bone mineral density in elderly men and women. Am J Clin Nutr. 2000; 71:1201–1208.
3. Feskanich D. et al. Vitamin K intake and hip fractures in women: a prospective study. Am J Clin Nutr. 1999; 69:74–79.
4. Rejnmark L. et al. No effect of vitamin K1 intake on bone mineral density and fracture risk in perimenopausal women. Osteoporos Int. 2006; 17:1122–1132.