Clinical Correlates and Heritability of Vitamins K and D.

Nutritional influences on bone health are well-characterized. Yet, little is known about the correlates and heritability of vitamins K and D, both of which are involved in bone mineralization. The clinical correlates and heritability of measures of vitamin K (plasma phylloquinone and serum % undercarboxylated osteocalcin) and vitamin D status [plasma 25(OH)D] were assessed in 843 men and 919 women (mean age 59 yrs) participating in the Framingham Offspring Study. Associations between biologically plausible clinical factors and measures of vitamins K and D status were determined using stepwise regression. Heritability was determined by SOLAR. Clinical factors accounted for 13.1 (men) and 16.3% (women) of the variability in plasma phylloquinone, with triglycerides and vitamin K intake being the primary correlates; heritability estimates were non-significant. In men 17.1%, and in women 14.6% of the variability in %ucOC was explained by clinical factors in our models; estimated heritability was significant at 23.3% (p = 0.01). Season and vitamin D intake explained 24.7% (men) and 23.8 % (women) of the variability in plasma 25(OH)D, and estimated heritability was 34.8% (p<0.01). In summary, plasma phylloquinone was not significantly heritable, but was associated with triglycerides and vitamin K intake. In contrast, %ucOC, and 25(OH)D were found to be significantly heritable. [ABSTRACT FROM AUTHOR]