Quantification of Vitamin B12 intakes, serum concentrations and primary and secondary food sources of non-Hispanic white and non-Hispanic black older adults in National Health and Nutrition Examination Survey 2003-200

Background. Serum concentrations of vitamin B12 (B12) amongst non-Hispanic blacks (blacks) are higher than those of non-Hispanic whites (whites) despite lower B12 intakes in blacks.;Objective. (1) Quantify dietary intakes and identify main food sources contributing to B12 intakes of older white and blacks, and (2) identify food sources most predictive of B12 status on the basis of serum B12 levels.;Design. Cross-sectional survey; 24-hour dietary recall, serum B12 and homocysteine concentrations. Inadequate B12 was defined as serum B12 <258 pmol/L (exclusions for elevated creatinine). Focus was on dietary intakes of B12 from food sources.;Results. Whites had greater total B12 intakes than blacks (6.25 microg vs, 4.86 microg; p<0.0005) despite having lower mean serum B12 concentrations than blacks (400 pmol/L vs, 467 pmol L: p=0.002). Meat was the main primary source of B12 intake of both groups (38% whites, 54% blacks); cereal was the main secondary source (28% whites, 21% blacks). Grain (38%) was the greatest contributor to total B12 intake for serum B12 adequate whites, while soup (29%) was greatest when examined per 1000 calories. Meat (55%) was the greatest contributor to total B12 intake for serum B12 adequate blacks, while dairy (24%) was greatest when examined per 1000 calories.;Conclusions. Whites and blacks consume similar foods, but in different proportions, to obtain dietary B12. It appears that serum B12 adequate whites and blacks may have a more varied selection of foods to obtain dietary B12 than their serum inadequate counterparts, including foods not identified before such as meal replacements and protein supplements. Compared to their serum B12 adequate counterparts, serum B12 inadequate whites may have an over-dependence on frozen meals and serum B12 inadequate blacks may have an over reliance on soups to obtain dietary B12.