title: Phylloquinone in plasma from elderly and young adults: factors influencing its concentration.
abstract: Fasting plasma phylloquinone concentrations were determined by reverse-phase high-performance liquid chromatography in a population of young (n = 131) and elderly (n = 195) human subjects. The distribution of values was non-Gaussian but was converted to Gaussian form after a logarithmic transformation of the data. The normal range derived from the lognormal distribution was 0.29-2.64 nmol/L (geometric means = 0.87 nmol/L, median = 0.86 nmol/L). Young females had significantly decreased plasma phylloquinone concentrations when compared with the elderly females whereas concentrations in young males were slightly higher than those in elderly males. A regression model was constructed and revealed that plasma phylloquinone concentrations were positively correlated with plasma triglycerides and alpha-tocopherol. Although the elderly subjects (means = 1.05 nmol/L) had higher levels of phylloquinone than the young subjects (0.94 nmol/L), when the concentration of phylloquinone in plasma is expressed as nanomoles phylloquinone per millimole of triglyceride, the elderly subjects (0.62 x 10(-6) showed decreased levels for phylloquinone compared with the young subjects (0.82 x 10(-6) (p less than 0.001).
authors.affiliation: USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.
authors.forename: J A
authors.initials: JA
authors.lastname: Sadowski
authors.forename: S J
authors.initials: SJ
authors.lastname: Hood
authors.forename: G E
authors.initials: GE
authors.lastname: Dallal
authors.forename: P J
authors.initials: PJ
authors.lastname: Garry
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D005215:Fasting; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D012737:Sex Factors; D014280:Triglycerides / Q000097:blood; D014801:Vitamin A / Q000097:blood; D014810:Vitamin E / Q000097:blood; D014812:Vitamin K / Q000097:blood; D010837:Vitamin K 1 / Q000097:blood*
chemical_list: D014280:Triglycerides; D014801:Vitamin A; D014812:Vitamin K; D014810:Vitamin E; D010837:Vitamin K 1