Vitamin B-12 deficiency is a recognized problem among older adults, although vitamin B-12 status among differing ethnic groups remains unclear. We examined vitamin B-12 intake and status in a representative sample of elderly Hispanics of Caribbean origin (Puerto Rican and Dominican) and non-Hispanic whites. Dietary intake and plasma values were available for 347 Puerto Ricans, 102 Dominicans and 154 non-Hispanic whites (60-93 y). Relative to non-Hispanic whites, Hispanics had significantly lower vitamin B-12 intake and plasma concentrations; 17% of Hispanics and 10% of non-Hispanic whites had concentrations < 185 pmol/L (P < 0.05). Among Hispanics, log transformed vitamin B-12 intake was significantly associated with plasma concentration (beta = 60 pmol/L per log unit vitamin B-12 intake, P < 0.002 for supplement users and beta = 74 pmol/L per log unit vitamin B-12 intake, P < 0.01 for nonsupplement users). Intake and plasma concentrations were significantly associated among non-Hispanic whites only when supplement users were included (beta = 95 pmol/L per log unit vitamin B-12 intake, P < 0.0001). Hispanic supplement users (18%) had higher plasma concentrations than did nonsupplement users (364 +/- 17 and 297 +/- 8 pmol/L, respectively, P < 0.001). For Hispanics, consumption of breakfast cereal > 4 times/wk compared to no cereal was protective against lower plasma concentrations (8 vs. 24% < 185 pmol/L, P < 0.01). Approximately 40% of both groups with plasma vitamin B-12 < 185 pmol/L had homocysteine > 14 micromol/L, relative to < 17% of those with B-12 > 185 pmol/L. The high prevalence of low vitamin B-12 status in elderly Hispanics appears largely attributed to inadequate intake. As in other populations, sources of unbound vitamin B-12 such as supplements and fortified cereal appear to be protective. Dietary intervention programs targeted to the Hispanic population should promote these vitamin B-12 sources.