INTERMAP is a basic epidemiologic investigation to clarify unanswered questions on the role of macronutrients and micronutrients in the etiology of unfavorable blood pressure (BP) patterns prevailing for most middle-aged and older individuals. Supported by NHLBI, ten primary hypotheses, four subgroup hypotheses and multiple exploratory questions on diet and BP are being addressed in this high-quality international cooperative 17-sample population study of 4,680 men and women ages 40-59 from four countries (China, Japan, UK, US) - of varied ethnic-racial and sociodemographic backgrounds - consuming diverse diets. Analyses use extensive data on nutrient intake from four 24-hour recalls and the 4 country databases (developed by INTERMAP) on nutrient composition of all reported foods (data on 71 nutrients), and from two 24-hr urine collections on Na, K, Ca, Mg, urea, creatinine, volume and microalbuminuria. NHLBI-funded research in progress or pending includes analysis of urinary amino acids of each individual, coding of reported dietary supplements, and special NMR-HPLC analyses of 24-hour urine specimens. New work proposed here - on B vitamin intake and BP - is novel, exploratory, knowledge-generating and "pre-competitive" in nature, in keeping with the aims of this RFA. It is based on new and unprecedented findings, from ongoing INTERMAP analyses for its 2,195 US participants. These data indicate that lower dietary thiamin, riboflavin, B6, and folate (considered singly) is associated with higher systolic BP (SBP), and plays a role in the higher SBP of African-Americans and of less educated Americans of all ethnicities. These results open up a new research area, on B vitamin intake and BP. These analyses were done only for US participants since data on B vitamin composition of foods are missing for Chinese, Japanese, and UK participants. This application requests funds to overcome this data gap, and make possible comprehensive analyses for all 4,680 participants on relations of B vitamin intake (from foods, supplements, and foods plus supplements) to BP, and to other variables, i.e., to make links between data on B vitamin and other nutrient intakes, urinary data on multiple metabolic characteristics (elucidated by routine and special NMR-HPLC analyses), and SBP/DBP - links not available on populations from any other research.