Folate-vitamin B-12 interaction in relation to cognitive impairment, anemia, and biochemical indicators of vitamin B-12 deficiency Export

@article{citeulike:3906005, abstract = {Previous reports on pernicious anemia treatment suggested that high folic acid intake adversely influences the natural history of vitamin B-12 deficiency, which affects many elderly individuals. However, experimental investigation of this hypothesis is unethical, and the few existing observational data are inconclusive. With the use of data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES), we evaluated the interaction between high serum folate and low vitamin B-12 status [ie, plasma vitamin B-12 < 148 pmol/L or methylmalonic acid (MMA) > 210 nmol/L] with respect to anemia and cognitive impairment. With subjects having both plasma folate [\&le;] 59 nmol/L and normal vitamin B-12 status as the referent category, odds ratios for the prevalence of anemia compared with normal hemoglobin concentration and impaired compared with unimpaired cognitive function were 2.1 (95\% CI: 1.1, 3.7) and 1.7 (95\% CI: 1.01, 2.9), respectively, for those with low vitamin B-12 status but normal serum folate and 4.9 (95\% CI: 2.3, 10.6) and 5.0 (95\% CI: 2.7, 9.5), respectively, for those with low vitamin B-12 status and plasma folate >59 nmol/L. Among subjects with low vitamin B-12 status, mean circulating vitamin B-12 was 228 pmol/L for the normal-folate subgroup and 354 pmol/L for the high-folate subgroup. We subsequently showed increases in circulating homocysteine and MMA concentrations with increasing serum folate among NHANES participants with serum vitamin B-12 < 148 pmol/L, whereas the opposite trends occurred among subjects with serum vitamin B-12 [\&ge;] 148 pmol/L. These interactions, which were not seen in NHANES III before fortification, imply that, in vitamin B-12 deficiency, high folate status is associated with impaired activity of the 2 vitamin B-12-dependent enzymes, methionine synthase and MMA-coenzyme A mutase. 10.3945/ajcn.2008.26947C}, author = {Selhub, Jacob and Morris, Martha S. and Jacques, Paul F. and Rosenberg, Irwin H.}, citeulike-article-id = {3906005}, citeulike-linkout-0 = {http://dx.doi.org/10.3945/ajcn.2008.26947C}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19141696}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19141696}, day = {13}, doi = {10.3945/ajcn.2008.26947C}, journal = {Am J Clin Nutr}, keywords = {anemia, b-12, b-12\_deficiency, cognitive\_impairment, folate}, month = {January}, pages = {ajcn.2008.26947C+}, posted-at = {2009-01-18 12:39:16}, priority = {2}, title = {Folate-vitamin B-12 interaction in relation to cognitive impairment, anemia, and biochemical indicators of vitamin B-12 deficiency}, url = {http://dx.doi.org/10.3945/ajcn.2008.26947C}, year = {2009} }

TY - JOUR ID - citeulike:3906005 L3 - citeulike-article-id:3906005 N2 - Previous reports on pernicious anemia treatment suggested that high folic acid intake adversely influences the natural history of vitamin B-12 deficiency, which affects many elderly individuals. However, experimental investigation of this hypothesis is unethical, and the few existing observational data are inconclusive. With the use of data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES), we evaluated the interaction between high serum folate and low vitamin B-12 status [ie, plasma vitamin B-12 < 148 pmol/L or methylmalonic acid (MMA) > 210 nmol/L] with respect to anemia and cognitive impairment. With subjects having both plasma folate [&le;] 59 nmol/L and normal vitamin B-12 status as the referent category, odds ratios for the prevalence of anemia compared with normal hemoglobin concentration and impaired compared with unimpaired cognitive function were 2.1 (95% CI: 1.1, 3.7) and 1.7 (95% CI: 1.01, 2.9), respectively, for those with low vitamin B-12 status but normal serum folate and 4.9 (95% CI: 2.3, 10.6) and 5.0 (95% CI: 2.7, 9.5), respectively, for those with low vitamin B-12 status and plasma folate >59 nmol/L. Among subjects with low vitamin B-12 status, mean circulating vitamin B-12 was 228 pmol/L for the normal-folate subgroup and 354 pmol/L for the high-folate subgroup. We subsequently showed increases in circulating homocysteine and MMA concentrations with increasing serum folate among NHANES participants with serum vitamin B-12 < 148 pmol/L, whereas the opposite trends occurred among subjects with serum vitamin B-12 [&ge;] 148 pmol/L. These interactions, which were not seen in NHANES III before fortification, imply that, in vitamin B-12 deficiency, high folate status is associated with impaired activity of the 2 vitamin B-12-dependent enzymes, methionine synthase and MMA-coenzyme A mutase. 10.3945/ajcn.2008.26947C JF - Am J Clin Nutr TI - Folate-vitamin B-12 interaction in relation to cognitive impairment, anemia, and biochemical indicators of vitamin B-12 deficiency SP - ajcn.2008.26947C KW - anemia KW - b-12 KW - b-12_deficiency KW - cognitive_impairment KW - folate AU - Selhub, Jacob AU - Morris, Martha AU - Jacques, Paul AU - Rosenberg, Irwin PY - 2009/01/13/ UR - http://dx.doi.org/10.3945/ajcn.2008.26947C ER -