{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,3]],"date-time":"2025-11-03T18:37:15Z","timestamp":1762195035916,"version":"build-2065373602"},"reference-count":30,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2013,3,21]],"date-time":"2013-03-21T00:00:00Z","timestamp":1363824000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J American Geriatrics Society"],"published-print":{"date-parts":[[2013,4]]},"abstract":"\n Objectives<\/jats:title>\n To determine whether high serum folate levels contribute to metabolite changes in elderly subjects with normal cobalamin levels.<\/jats:p>\n <\/jats:sec>\n \n Design<\/jats:title>\n Case series.<\/jats:p>\n <\/jats:sec>\n \n Setting<\/jats:title>\n Outpatient clinic at a university\u2010based staff model health maintenance organization.<\/jats:p>\n <\/jats:sec>\n \n Participants<\/jats:title>\n Two hundred thirty\u2010three ambulatory individuals without diabetes mellitus with normal renal function and normal cobalamin levels evaluated for cobalamin deficiency.<\/jats:p>\n <\/jats:sec>\n \n Measurements<\/jats:title>\n \n Cobalamin, serum folate, methylmalonic acid (\n MMA<\/jats:styled-content>\n ), and homocysteine.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Older individuals (\u226560) with low\u2010normal cobalamin levels (201\u2013300\u00a0pg\/mL) had higher\n MMA<\/jats:styled-content>\n and lower homocysteine levels when serum folate levels were high (>20\u00a0ng\/mL) than when serum folate levels were normal (\n P<\/jats:italic>\n \u00a0<\u00a0.02), but serum folate levels within the normal range were not a determinant of either metabolite. In younger subjects with low\u2010normal cobalamin levels, high serum folate levels were not associated with significant differences in either metabolite. At mid\u2010normal cobalamin levels (301\u2013600\u00a0pg\/mL), high serum folate levels were associated with lower homocysteine levels in older adults (\n P<\/jats:italic>\n \u00a0<\u00a0.001) but not with differences in\n MMA<\/jats:styled-content>\n in either age group. Cobalamin therapy decreased or normalized\n MMA<\/jats:styled-content>\n and homocysteine in 89% or more of participants even at pretherapy cobalamin levels greater than 600\u00a0pg\/mL.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n \n High serum folate levels are associated with higher\n MMA<\/jats:styled-content>\n levels when cobalamin levels are low\u2010normal, and this effect is age dependent, not progressive within the normal serum folate range (suggesting a threshold effect), and reversed by cobalamin therapy. Because\n MMA<\/jats:styled-content>\n may be neurotoxic, these findings suggest caution in the use of folic acid supplements in elderly adults.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1111\/jgs.12155","type":"journal-article","created":{"date-parts":[[2013,3,23]],"date-time":"2013-03-23T01:42:54Z","timestamp":1364002974000},"page":"577-582","source":"Crossref","is-referenced-by-count":21,"title":["Advanced Age as a Risk Factor for Folate\u2010Associated Functional Cobalamin Deficiency"],"prefix":"10.1111","volume":"61","author":[{"given":"Lawrence R.","family":"Solomon","sequence":"first","affiliation":[{"name":"Section of Palliative Care Department of Medicine School of Medicine Yale University New Haven Connecticut"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2013,3,21]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1474-4422(06)70598-1"},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-3476(64)80396-6"},{"key":"e_1_2_6_4_1","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/85.1.193"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0709487104"},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.3945\/ajcn.2009.27514"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00125-007-0793-y"},{"key":"e_1_2_6_8_1","doi-asserted-by":"publisher","DOI":"10.3177\/jnsv.57.130"},{"key":"e_1_2_6_9_1","doi-asserted-by":"publisher","DOI":"10.1093\/hmg\/ddr289"},{"key":"e_1_2_6_10_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1005631230455"},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijdevneu.2005.10.005"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/85.1.3"},{"key":"e_1_2_6_13_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0711541105"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.3945\/ajcn.111.014621"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.blre.2006.05.001"},{"key":"e_1_2_6_16_1","doi-asserted-by":"publisher","DOI":"10.1373\/clinchem.2003.021717"},{"key":"e_1_2_6_17_1","doi-asserted-by":"publisher","DOI":"10.1373\/clinchem.2006.080382"},{"key":"e_1_2_6_18_1","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2004-04-1641"},{"key":"e_1_2_6_19_1","doi-asserted-by":"publisher","DOI":"10.2337\/dc11-0009"},{"key":"e_1_2_6_20_1","doi-asserted-by":"crossref","first-page":"2277","DOI":"10.1093\/clinchem\/35.12.2277","article-title":"Studies on methylmalonic acid in humans: II. 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