Dietary vitamins K1, K2 and bone mineral density: the Hordaland Health Study

Abstract

Associations between bone mineral density (BMD) and dietary vitamins K1 and K2 in 4,461 individuals were studied. For women, odds ratio of low BMD was 1.48 in lowest to highest quartile of K1. A weak positive association was found for K2. Our results do not support dietary vitamins K as being major determinants of BMD.Purpose Some studies suggest a positive association between intake of vitamin K1 (phylloquinone) or vitamin K2 (menaquinone) and BMD. The objective was to examine associations between BMD and dietary vitamins K1 and K2.Methods BMD of the total hip was measured in 2,575 women and 1,886 men, 47-50 and 71-75 years, in the community-based Hordaland Health Study. Dietary vitamins K1 and K2 were assessed by a food frequency questionnaire. Low BMD was defined as the lowest BMDquintile for each age-sex group. Multiple linear, logistic and fractional polynomial regression analyses were applied. Results No significant associations between vitamin K1 or K2 intake and BMD were found in linear regression analyses. Comparing women in the highest to lowest quartile of vitamin K1 intake, an odds ratio of 1.48 (95% confidence interval (CI): 1.08, 2.04) for low BMD was found. This was not found among men or for vitamin K2 intake in either gender. A weak, positive association between log (vitamin K2) intake and BMD was found by fractional polynomial regression analyses in women (beta coefficient: 0.018; 95% CI: 0.009, 0.027; p=0.001), but not in men. Conclusions Although we observed an increased risk of low BMD with low intake of vitamin K1 and a weak positive association between BMD and vitamin K2 intake among women, this study does not support dietary intake of vitamins K1 or K2 as major determinants of BMD. Future studies should investigate possible associations between intake of vitamin K1, K2 and fracture risk.

Reduced bone resorption by intake of dietary vitamin D and K from tailor-made Atlantic salmon: a randomized intervention trial

“…However, even though the documentations of similar effects of vitamin K 1 is not as strong as K 2 , a combination of low serum levels of vitamins K 1 and D have been associated with increased risk of hip fracture in elderly [ 37 ]. Both low levels and intakes of vitamin K 1 have been associated with osteoporosis [ 19 – 22 ], and our findings indicate that vitamin K 1 has a positive effect as well.…”

“…In humans, the fraction of the circulating osteocalcin that is not γ-carboxylated (GLU/GLA) is used as a biomarker of vitamin K status [ 17 , 18 ]. Low levels of vitamin K 1 and K 2 has been observed in osteoporotic patients [ 19 , 20 ], and low dietary intake of vitamin K 1 has been associated with low bone mineral density (BMD) and increased risk of hip fracture [ 21 , 22 ]. Furthermore, it is shown that undercarboxylated osteocalcin increases with age [ 23 ], and high levels are associated with both lower BMD and increased risk of hip fracture [ 24 , 25 ].…”

The role of menaquinones (vitamin K2) in human health

“…For example, two Japanese studies showed that the usual dietary intake of natto was effective in maintaining bone stiffness ( 97 ) and was positively associated with a 3-year change in BMD at the femoral neck ( 98 ) . Within Norwegian individuals, no linear association was found between dietary menaquinones and BMD of the total hip; however, fractional polynomial regression analyses for the detection of non-linear associations showed a small, positive association between dietary menaquinones and BMD among women ( 99 ) . Of note, these studies described a proposed effect of dietary menaquinones via natto consumption.…”

Dietary reference values for vitamin K

“…Described in Apalset et al. (): (Koivu‐Tikkanen et al., ; Schurgers and Vermeer, ); Finnish food composition database (National Institute for Health and Welfare, )…”