RESULTS OF B-VITAMIN SUPPLEMENTATION STUDY USED IN A PREDICTION MODELTO DEFINE A REFERENCE RANGE FOR PLASMA HOMOCYSTEINE

Because high plasma concentrations of homocysteine constitute an enhan ced risk for premature coronary heart disease, it is necessary to esta blish a reference range for normal concentrations of plasma homocystei ne. The frequency distribution of plasma homocysteine concentrations t ails to the right, and the nonparametric approach is unsatisfactory fo r defining a normal plasma homocysteine reference range. By using subj ects' responses to appropriate vitamin supplementation, we developed a mathematical prediction model to calculate the plasma homocysteine co ncentration that could be expected for each individual treated with a vitamin supplement. With this model, we can predict that plasma homocy steine concentrations will approach a normal frequency distribution wi th a 95% reference range (mean +/- 2 SD) of 4.9-11.7 mu mol/L, provide d the vitamin status of the study population is improved.