1.Reynolds, EH (1976) The neurology of vitamin B12 deficiency. Metabolic mechanisms. Lancet ii, 832–833.
2.Scott, JM & Weir, DG (1994) Folate/vitamin B12 interrelationship. Essays in Biochemistry 28, 63–72.
3.Scott, JM, Dinn, JJ, Wilson, P & Weir, DG (1981) Pathogenesis of subacute combined degeneration: a result of methyl group deficiency. Lancet ii, 334–337.
4.Woodman, R, Ferrucci, L & Guralnik, J (2005) Anemia in older adults. Curr Opin Hematol 12, 123–128.
5.Schjonsby, H (1989) Vitamin B12 absorption and malabsorption. Gut 12, 1686–1691.
6.Chang, EB, Sitrin, MD & Black, DD (editors) (1996) Gastrointestinal Hepatobiliary and Nutritional Physiology. Philadelphia, PA: Lippincott-Raven.
7.Baik, HW & Russell, RM (1999) Vitamin B12 deficiency in the elderly. Annu Rev Nutr 19, 357–377.
8.Berlin, H, Berlin, R & Brante, G (1968) Oral treatment of pernicious anemia with high doses of vitamin B12 without intrinsic factor. Acta Med Scand 184, 247–258.
9.Nexo, E, Hansen, M, Rasmussen, K, Lindgren, A & Grasbeck, R (1994) How to diagnose cobalamin deficiency. Scand J Clin Lab Invest Suppl 219, 61–76.
10.Matthews, JH (1995) Cobalamin and folate deficiency in the elderly. Baillieres Clin Haematol 8, 679–697.
11.Pautas, E, Cherin, P, de Jaeger, C & Godeau, P (1999) Carence en vitamine B12 chez le sujet age (Vitamin B12 deficiency in the elderly). Presse Med 28, 1767–1770.
12.Andres, E, Goichot, B & Schlienger, JL (2000) Food cobalamin malabsorption: a usual cause of vitamin B12 deficiency. Arch Intern Med 160, 2061–2062.
13.Andres, E, Kaltenbach, G, Perrin, AE, Kurtz, JE & Schlienger, JL (2002) Food-cobalamin malabsorption in the elderly. Am J Med 113, 351–352.
14.Andres, E, Perrin, AE, Demangeat, C, Kurtz, JE, Vinzio, S, Grunenberger, F, Goichot, B & Schlienger, JL (2003) The syndrome of food-cobalamin malabsorption revisited in a department of internal medicine. A monocentric cohort study of 80 patients. Eur J Intern Med 14, 221–226.
15.Loukili, NH, Noel, E, Blaison, G, Goichot, B, Kaltenbach, G, Rondeau, M & Andres, E (2004) Update of pernicious anemia. A retrospective study of 49 cases. Rev Med Interne 25, 556–561.
16.Carmel, R (1995) Malabsorption of food cobalamin. Baillieres Clin Haematol 8, 639–655.
17.Carmel, R, Aurangzeb, I & Qian, D (2001) Associations of food-cobalamin malabsorption with ethnic origin, age, Helicobacter pylori infection, and serum markers of gastritis. Am J Gastroenterol 96, 63–70.
18.Kaptan, K, Beyan, C, Ural, AU, Cetin, T, Avcu, F, Gulsen, M, Finci, R & Yalcin, A (2000) Helicobacter pylori – is it a novel causative agent in vitamin B12 deficiency? Arch Intern Med 160, 1349–1353.
19.Bauman, WA, Shaw, S, Jayatilleke, E, Spungen, AM & Herbert, V (2000) Increased intake of calcium reverses vitamin B12 malabsorption induced by metformin. Diabetes Care 23, 1227–1231.
20.Andres, E, Noel, E & Goichot, B (2002) Metformin-associated vitamin B12 deficiency. Arch Intern Med 162, 2251–2252.
21.Howden, CW (2000) Vitamin B12 levels during prolonged treatment with proton pump inhibitors. J Clin Gastroenterol 30, 29–33.
22.Andres, E, Noel, E & Abdelghani, MB (2003) Vitamin B12 deficiency associated with chronic acid suppression therapy. Ann Pharmacother 37, 1730.
23.Termanini, B, Gibril, F, Sutliff, VE, Yu, F, Venzon, DJ & Jensen, RT (1998) Effect of long-term gastric acid suppressive therapy on serum vitamin B12 levels in patients with Zollinger-Ellison syndrome. Am J Med 104, 422–430.
24.Carmel, R (2000) Current concepts in cobalamin deficiency. Annu Rev Med 51, 357–375.
25.Lee, GR & Herbert, V (1999) Pernicious anemia. In Wintrobe's Clinical Hematology, 10th ed., pp. 941–978 [Lee, GR, Foerster, J, Lukens, J, Paraskevas, F, Greer, JP and Rodgers, GM editors]. Philadelphia, PA: Williams and Wilkins.
26.Pruthi, RK & Tefferi, A (1994) Pernicious anemia revisited. Mayo Clin Proc 69, 144–150.
27.Toh, BH, van Driel, IR & Gleeson, PA (1997) Pernicious anemia. N Engl J Med 337, 1441–1448.
28.Nicolas, JP & Gueant, JL (1994) Absorption, distribution and excretion of vitamin B12. Ann Gastroenterol Hepatol 30, 270–276.
29.Herbert, V (1994) Staging vitamin B12 (cobalamin) status in vegetarians. Am J Clin Nutr 59, Suppl., 1213S–1222S.
30.Russell, RM (1992) Vitamin requirements in old age. Age Nutrition 3, 20–23.
31.Andres, E, Perrin, AE, Kraemer, JP, Goichot, B, Demengeat, C, Ruellan, A, Grunenberger, F, Constantinesco, A & Schlienger, JL (2000) Anemia caused by vitamin B 12 deficiency in subjects aged over 75 years: new hypotheses. A study of 20 cases. Rev Med Interne 21, 946–954.
32.Joosten, E, van den Berg, A, Riezler, R, Naurath, HJ, Lindenbaum, J, Stabler, SP & Allen, RH (1993) Metabolic evidence that deficiencies of vitamin B-12 (cobalamin), folate, and vitamin B6 occur commonly in elderly people. Am J Clin Nutr 58, 468–476.
33.Bates, CJ, Schneede, J, Mishra, G, Prentice, A & Mansoor, MA (2003) Relationship between methylmalonic acid, homocysteine, vitamin B12 intake and status and socio-economic indices, in a subset of participants in the British National Diet and Nutrition Survey of people aged 65 y and over. Eur J Clin Nutr 57, 349–357.
34.Clarke, R, Refsum, H, Birks, J et al. (2003) Screening for vitamin B12 and folate deficiency in older persons. Am J Clin Nutr 77, 1241–1247.
35.Savage, D & Lindenbaum, J (1983) Relapses after interruption of cyanocobalamin therapy in patients with pernicious anemia. Am J Med 74, 765–772.
36.Stabler, SP & Allen, RH (2004) Vitamin B12 deficiency as a worldwide problem. Annu Rev Nutr 24, 299–326.
37.Carmel, R (1996) Prevalence of undiagnosed pernicious anemia in the elderly. Arch Intern Med 156, 1097–1100.
38.Bjorkegren, K & Svardsudd, K (2004) A population-based intervention study on elevated serum levels of methylmalonic acid and total homocysteine in elderly people: results after 36 months of follow-up. J Intern Med 256, 446–452.
39.Healton, EB, Savage, DG, Brust, JC, Garrett, TJ & Lindenbaum, J (1991) Neurologic aspects of cobalamin deficiency. Medicine 70, 229–245.
40.Stabler, SP (1995) Screening the older population for cobalamin (vitamin B12) deficiency. J Am Geriatr Soc 43, 1290–1297.
41.Chanarin, I & Metz, J (1997) Diagnosis of cobalamin deficiency: the old and the new. Br J Haematol 97, 695–700.
42.Snow, CF (1999) Laboratory diagnosis of vitamin B12 and folate deficiency: a guide for the primary care physician. Arch Intern Med 159, 1289–1298.
43.Lindenbaum, J, Healton, EB, Savage, DG, Brust, JC, Garrett, TJ, Podell, ER, Marcell, PD, Stabler, SP & Allen, RH (1988) Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis. N Engl J Med 318, 1720–1728.
44.Savage, DG, Ogundipe, A, Allen, RH, Stabler, SP & Lindenbaum, J (2000) Etiology and diagnostic evaluation of macrocytosis. Am J Med Sci 319, 343–352.
45.Herbert, V (1987) Nutrition science as a continually unfolding story: the folate and vitamin B12 paradigm. Am J Clin Nutr 46, 387–402.
46.Carmel, R (1988) Pernicious anemia. The expected findings of very low serum cobalamin levels, anemia, and macrocytosis are often lacking. Arch Intern Med 148, 1712–1714.
47.Finch, S, Doyle, W, Lowe, C, Bates, CJ, Prentice, A, Smithers, G & Clarke, PC (1998) The National Diet and Nutrition Survey: People Aged 65 Years or Over. vol. 1: Report of the Diet and Nutrition Survey. London: H. M. Stationery Office.
48.Department of Health (2000) Folic Acid and the Prevention of Disease. London: The Stationery Office.
49.Thompson, WG, Babitz, L, Cassino, C, Freedman, M & Lipkin, M Jr (1987) Evaluation of current criteria used to measure vitamin B12 levels. Am J Med 82, 291–294.
50.Thompson, WG, Cassino, C, Babitz, L, Meola, T, Berman, R, Lipkin, M Jr & Freedman, M (1989) Hypersegmented neutrophils and vitamin B12 deficiency. Hypersegmentation in B12 deficiency. Acta Haematol 81, 186–191.
51.Oosterhuis, WP, Niessen, RW, Bossuyt, PM, Sanders, GT & Sturk, A (2000) Diagnostic value of the mean corpuscular volume in the detection of vitamin B12 deficiency. Scand J Clin Lab Invest 60, 9–18.
52.Bessman, JD, Gilmer, PR Jr & Gardner, FH (1983) Improved classification of anemias by MCV and RDW. Am J Clin Pathol 80, 322–326.
53.Mooney, KM, Young, IS, Patterson, CC & Cuskelly, GJ (2004) Vitamin B12 status in elderly subjects with low haemoglobin. Proc Nut Soc 63, 77A.
54.Schneede, J & Ueland, PM (2005) Novel and established markers of cobalamin deficiency: complementary or exclusive diagnostic strategies. Semin Vasc Med 5, 140–155.
55.Carmel, R (1990) Subtle and atypical cobalamin deficiency states. Am J Hematol 34, 108–114.
56.Carmel, R, Green, R, Rosenblatt, DS & Watkins, D (2003) Update on cobalamin, folate, and homocysteine. Hematology (Am Soc Hematol Educ Program) 1, 62–81.
57.Lindenbaum, J, Savage, DG, Stabler, SP & Allen, RH (1990) Diagnosis of cobalamin deficiency: II. Relative sensitivities of serum cobalamin, methylmalonic acid, and total homocysteine concentrations. Am J Hematol 34, 99–107.
58.Ward, PC (2002) Modern approaches to the investigation of vitamin B12 deficiency. Clin Lab Med 22, 435–445.
59.Bose, S, Seetharam, S & Seetharam, B (1995) Membrane expression and interactions of human transcobalamin II receptor. J Biol Chem 270, 8152–8157.
60.Bor, MV, Nexo, E & Hvas, AM (2004) Holo-transcobalamin concentration and transcobalamin saturation reflect recent vitamin B12 absorption better than does serum vitamin B12. Clin Chem 50, 1043–1049.
61.Hvas, AM & Nexo, E (2003) Holotranscobalamin as a predictor of vitamin B12 status. Clin Chem Lab Med 41, 1489–1492.
62.Carmel, R (2002) Measuring and interpreting holo-transcobalamin(holo-transcobalamin II). Clin Chem 48, 407–409.
63.Anwar, W, Gerard, P, Moutabarrek, A, Namour, F & Gueant, JL (2004) End-stage renal disease increases plasma transcobalamin and neutralizes influence of TCN 776C>G polymorphism. Kidney Int 66, 2092–2093.
64.Fodinger, M, Veitl, M, Skoupy, S et al. (2003) Effect of TCN2 776C>G on vitamin B12 cellular availability in end-stage renal disease patients. Kidney Int 64, 1095–1100.
65.Riedel, B, Bjorke Monsen, AL, Ueland, PM & Schneede, J (2005) Effects of oral contraceptives and hormone replacement therapy on markers of cobalamin status. Clin Chem 51, 778–781.
66.Savage, DG, Lindenbaum, J, Stabler, SP & Allen, RH (1994) Sensitivity of serum methylmalonic acid and total homocysteine determinations for diagnosing cobalamin and folate deficiencies. Am J Med 96, 239–246.
67.Stabler, SP, Marcell, PD, Podell, ER, Allen, RH & Lindenbaum, J (1986) Assay of methylmalonic acid in the serum of patients with cobalamin deficiency using capillary gas chromatography-mass spectrometry. J Clin Invest 77, 1606–1612.
68.Pennypacker, LC, Allen, RH, Kelly, JP, Matthews, LM, Grigsby, J, Kaye, K, Lindenbaum, J & Stabler, SP (1992) High prevalence of cobalamin deficiency in elderly outpatients. J Am Geriatr Soc 40, 1197–1204.
69.Green, R (1996) Screening for vitamin B12 deficiency: caveat emptor. Ann Intern Med 124, 509–511.
70.Honein, MA, Paulozzi, LJ, Mathews, TJ, Erickson, JD & Wong, LY (2001) Impact of folic acid fortification of the US food supply on the occurrence of neural tube defects. JAMA 285, 2981–2986.
71.Kelly, P, McPartlin, J, Goggins, M, Weir, DG & Scott, JM (1997) Unmetabolized folic acid in serum: Acute studies in subjects consuming fortified food and supplements. Am J Clin Nutr 65, 1790–1795.
72.Bower, C & Wald, NJ (1995) Vitamin B12-deficiency and the fortification of food with folic-acid – review. Eur J Clin Nutr 49, 787–793.
73.Food Standards Agency (2002) Report from the Folic Acid Stakeholder meeting. London: Food Standards Agency.
74.Scientific Advisory Committee on Nutrition (2006) Folate and Disease Prevention. London: The Stationery Office.
75.Koehler, KM, Pareo-Tubbeh, SL, Romero, LJ, Baumgartner, RN & Garry, PJ (1997) Folate nutrition and older adults: challenges and opportunities. J Am Diet Assoc 97, 167–173.
76.Chanarin, I (1994) Adverse effects of increased dietary folate. Relation to measures to reduce the incidence of neural tube defects. Clin Invest Med 17, 244–252.
77.Savage, DG & Lindenbaum, J (1995) Folate-cobalamin interactions. In Folate in Health and Disease, pp. 237–285 [Bailey, LB editor]. New York: Marcel Dekker.
78.Food Standards Agency (2003) Safe Upper Limits for Vitamins and Minerals. London: Food Standards Agency.
79.Quinlivan, EP & Gregory, JF (2003) Effect of food fortification on folic acid intake in the United States. American Journal of Clinical Nutrition 77, 221–225.
80.Choumenkovitch, SF, Selhub, J, Wilson, PWF, Rader, JI, Rosenberg, IH & Jacques, PF (2002) Folic acid intake from fortification in United States exceeds predictions. Journal of Nutrition 132, 2792–2798.
81.Mills, JL, Von Kohorn, I, Conley, MR, Zeller, JA, Cox, C, Williamson, RE & Dufour, DR (2003) Low vitamin B12 concentrations in patients without anemia: the effect of folic acid fortification of grain. Am J Clin Nutr 77, 1474–1477.
82.Sweeney, MR, McPartlin, J, Weir, DG, Daly, L & Scott, JM (2006) Postprandial serum folic acid response to multiple doses of folic acid in fortified bread. Br J Nutr 95, 145–151.
83.Schneede, J (2003) Prerequisites for establishing general recommendations for diagnosis and treatment of vitamin B12 deficiency and cost-utility evaluation of these guidelines. Scand J Clin Lab Invest 63, 369–375.
84.Chui, CH, Lau, FY, Wong, R et al. (2001) Vitamin B12 deficiency – need for a new guideline. Nutrition 17, 917–920.
85.Scott, JM (2000) Folate and vitamin B12. In Human Nutrition and Dietetics, 10th ed., pp. 271–280 [Garrow, JS, James, WPT and Ralph, A editors]. London: Churchill Livingstone.