抄録
As an initial step to decide reference intervals of serum total vitamin B_6 and blood total nicotinic acid level, blood vitamin B_6 and nicotinic acid concentrations were determined in a group of healthy female students, 21-22 years old, who were confirmed with vitamin B_6 and nicotinic acid intake above their Recommended Dietary Allowances(RDA_s) by dietary survey. Serum vitamin B_6 and blood nicotinic acid were determined by isocratic postcolumn HPLC and reverse phase HPLC, respectively. Vitamin intakes were assessed from dietary record for consecutive 3 days. The mean of daily vitamin B_6 intake was 1.35±0.53mg/day and 13.0% of subjects showed lower than 0.016 on the ratio of vitamin B_6 (mg) / protein (g) intake. A significant correlation was found between intakes of vitamin B_6 and protein. Reference interval of serum total vitamin B_6 level which was obtained from the subjects with their intake above their RDA was 4 〜17 (9.1±2.7) ng/ml. The mean intake of the daily nicotinic acid equivalent was 24.0±5.9mg/day which was the amount of nicotinic acid and nicotinic acid converted from tryptophan. There was no subject who showed nicotinic acid intake lower than RDA (6.6mg/1,000kcal energy). Reference interval of blood total nicotinic acid level was 285〜710 (478.2±97.5)μg/dl from the subjects with nicotinic acid intake above their RDA.
