title: Interdependence of serum concentrations of vitamin K1, vitamin E, lipids, apolipoprotein A1, and apolipoprotein B: importance in assessing vitamin status.
abstract: Vitamin E (alpha-tocopherol) and vitamin K1 (phylloquinone) are fat-soluble vitamins and are important nutrients in health and disease. In this study serum concentrations of vitamin E and vitamin K1, lipids and apolipoproteins A1 and B were measured in neonates, normal and hyperlipidaemic individuals in an attempt to establish their interrelationships. A high degree of correlation was observed between the concentrations of the vitamins and those of lipids and apolipoproteins (r ranged from 0.42 to 0.92; p<0.001). Stepwise linear regression methods determined that serum concentrations of both vitamin E and vitamin K1 could best be predicted by using equations excluding lipids but containing only apolipoprotein A1 and B concentrations. Correlation coefficients between predicted and measured values were 0.89 for serum vitamin E, and 0.83 for serum vitamin K1 concentrations. To test the validity of the derived formulae, measured and estimated vitamin K1 and vitamin E concentrations in serum were determined in another group of neonates, normal adults and hypercholesterolemic adults and the comparisons were shown to be very good. These results indicate that the serum levels of both vitamins depend critically on the concentration of the lipoprotein carriers, apolipoproteins A1 and B. Hence, in order to identify variations in serum vitamin K1 and vitamin E concentrations, which are independent of variations in carrier concentration, it will be necessary to express these serum vitamins as ratios of vitamins to apolipoprotein A1 and B carriers.
authors.affiliation: The Curacel Institute of Medical Research, Rocklea, Queensland, Australia.
authors.forename: B E
authors.initials: BE
authors.lastname: Cham
authors.forename: J L
authors.initials: JL
authors.lastname: Smith
authors.forename: D M
authors.initials: DM
authors.lastname: Colquhoun
mesh_terms: D000328:Adult; D016632:Apolipoprotein A-I / Q000097:blood*; D001055:Apolipoproteins B / Q000097:blood*; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D015203:Reproducibility of Results; D014810:Vitamin E / Q000097:blood*; D010837:Vitamin K 1 / Q000097:blood*
chemical_list: D016632:Apolipoprotein A-I; D001055:Apolipoproteins B; D008055:Lipids; D014810:Vitamin E; D010837:Vitamin K 1