This Article  • Full text  • PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on HighWire  • Citing articles on ISI (145)  • Contact me when this article is cited  Related Content  • Related letter  • Related article  • Similar articles in this journal  Topic Collections  • Nutrition/ Malnutrition  • Pathology & Laboratory Medicine  • Review  • Alert me on articles by topic

A Guide for the Primary Care Physician

Christopher F. Snow, MD

Arch Intern Med. 1999;159:1289-1298.

At one time, the diagnosis of a deficiency of vitamin B₁₂ or folate was considered to be relatively straightforward. As knowledge has accumulated, the limitations of such tests as serum vitamin level measurements and the Schilling test have become apparent. With the development of newer tests, atypical and subclinical deficiency states have been recognized. In this review, available tests used in the diagnosis of vitamin B₁₂ and folate deficiency are discussed, and a rational approach to the diagnosis of these deficiency states is presented.

From the Division of Primary Care, Santa Clara Valley Medical Center, San Jose, and the Division of Internal Medicine, Stanford University, Stanford, Calif.

RELATED LETTER

Metformin and Vitamin B₁₂ Deficiency
Mary Ann Gilligan
Arch Intern Med. 2002;162(4):484-485.
EXTRACT | FULL TEXT  

RELATED ARTICLE

Archives of Internal Medicine Reader's Choice: Continuing Medical Education
Arch Intern Med. 1999;159(12):1378.
FULL TEXT  

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Vitamin B12 and Folate and the Risk of Anemia in Old Age: The Leiden 85-Plus Study
den Elzen et al.
Arch Intern Med 2008;168:2238-2244.
ABSTRACT | FULL TEXT  

An update on cobalamin deficiency in adults
Dali-Youcef and Andres
QJM 2008;0:hcn138v1-hcn138.
ABSTRACT | FULL TEXT  

Cutaneous lesions and vitamin B12 deficiency: An often-forgotten link
Kannan and Ng
cfp 2008;54:529-532.
FULL TEXT  

Plasma Folate, Vitamin B6, Vitamin B12, and Homocysteine and Pancreatic Cancer Risk in Four Large Cohorts
Schernhammer et al.
Cancer Res. 2007;67:5553-5560.
ABSTRACT | FULL TEXT  

Case 9-2007 -- A 27-Year-Old Woman with Pain and Swelling of the Legs
Vallat et al.
NEJM 2007;356:1252-1259.
FULL TEXT  

Hematologic manifestations of celiac disease
Halfdanarson et al.
Blood 2007;109:412-421.
ABSTRACT | FULL TEXT  

Acquired underproduction anemias
Zumberg and Leissinger
ASH-SAP 2007;2007:78-101.
FULL TEXT  

Risk factors of vitamin B12 deficiency in patients receiving metformin.
Ting et al.
Arch Intern Med 2006;166:1975-1979.
ABSTRACT | FULL TEXT  

Megaloblastic anemia and other causes of macrocytosis.
Aslinia et al.
Clin Med Res 2006;4:236-241.
FULL TEXT  

Analysis of methylmalonic Acid in plasma by liquid chromatography-tandem mass spectrometry.
Schmedes and Brandslund
Clin. Chem. 2006;52:754-757.
ABSTRACT | FULL TEXT  

Answer to Hypotonia: A Simple Hemogram
Kanra et al.
J Child Neurol 2005;20:930-931.
ABSTRACT  

Three Emerging New Drugs for NSCLC: Pemetrexed, Bortezomib, and Cetuximab
Dubey and Schiller
The Oncologist 2005;10:282-291.
ABSTRACT | FULL TEXT  

Cobalamin-responsive disorders in the ambulatory care setting: unreliability of cobalamin, methylmalonic acid, and homocysteine testing
Solomon
Blood 2005;105:978-985.
ABSTRACT | FULL TEXT  

Development and Validation of an Automated Chemiluminometric Immunoassay for Human Intrinsic Factor Antibodies in Serum
Gomez et al.
Clin. Chem. 2005;51:232-235.
FULL TEXT  

Case 30-2004 - A 37-Year-Old Woman with Paresthesias of the Arms and Legs
Marks and Zukerberg
NEJM 2004;351:1333-1341.
FULL TEXT  

Vitamin B12 (cobalamin) deficiency in elderly patients
Andres et al.
CMAJ 2004;171:251-259.
ABSTRACT | FULL TEXT  

Facts and Recommendations about Total Homocysteine Determinations: An Expert Opinion
Refsum et al.
Clin. Chem. 2004;50:3-32.
ABSTRACT | FULL TEXT  

Challenges in the Identification of Cobalamin-Deficiency Polyneuropathy
Saperstein et al.
Arch Neurol 2003;60:1296-1301.
ABSTRACT | FULL TEXT  

Vitamin B-12 metabolism in HIV-infected patients in the age of highly active antiretroviral therapy: role of homocysteine in assessing vitamin B-12 status
Remacha et al.
Am. J. Clin. Nutr. 2003;77:420-424.
ABSTRACT | FULL TEXT  

Metformin-Associated Vitamin B12 Deficiency
Andres et al.
Arch Intern Med 2002;162:2251-2252.
FULL TEXT  

Vitamins for Chronic Disease Prevention in Adults: Clinical Applications
Fletcher and Fairfield
JAMA 2002;287:3127-3129.
ABSTRACT | FULL TEXT  

Riboflavin Is a Determinant of Total Homocysteine Plasma Concentrations in End-Stage Renal Disease Patients
Skoupy et al.
J. Am. Soc. Nephrol. 2002;13:1331-1337.
ABSTRACT | FULL TEXT  

Vitamin B12 and Folic Acid in Children with Intestinal Parasitic Infection
Olivares et al.
J. Am. Coll. Nutr. 2002;21:109-113.
ABSTRACT | FULL TEXT  

Metformin and Vitamin B12 Deficiency
Gilligan
Arch Intern Med 2002;162:484-485.
FULL TEXT  

The effect of folic acid supplementation on plasma homocysteine in an elderly population
Rydlewicz et al.
QJM 2002;95:27-35.
ABSTRACT | FULL TEXT  

Association Between Erythrocyte Mean Corpuscular Volume and Peripheral Arterial Disease in Male Subjects: A Case Control Study
Mueller et al.
ANGIOLOGY 2001;52:605-613.
ABSTRACT  

Total Homocysteine, Vitamin B12, and Total Antioxidant Status in Vegetarians
Herrmann et al.
Clin. Chem. 2001;47:1094-1101.
ABSTRACT | FULL TEXT  

Evaluation of Indicators of Cobalamin Deficiency Defined as Cobalamin-induced Reduction in Increased Serum Methylmalonic Acid
Bolann et al.
Clin. Chem. 2000;46:1744-1750.
ABSTRACT | FULL TEXT  

Methylmalonic Acid Measured in Plasma and Urine by Stable-Isotope Dilution and Electrospray Tandem Mass Spectrometry
Magera et al.
Clin. Chem. 2000;46:1804-1810.
ABSTRACT | FULL TEXT  

Effect of MTHFR 1298A->C and MTHFR 677C->T Genotypes on Total Homocysteine, Folate, and Vitamin B12 Plasma Concentrations in Kdiney Graft Recipients
FÖDINGER et al.
J. Am. Soc. Nephrol. 2000;11:1918-1925.
ABSTRACT | FULL TEXT  

Cobalamin and Folate Evaluation: Measurement of Methylmalonic Acid and Homocysteine vs Vitamin B12 and Folate
Klee
Clin. Chem. 2000;46:1277-1283.
ABSTRACT | FULL TEXT  

Food Cobalamin Malabsorption: A Usual Cause of Vitamin B12 Deficiency
Andres et al.
Arch Intern Med 2000;160:2061-2062.
FULL TEXT  

The Risk of Cervical Cancer in Relation to Serum Concentrations of Folate, Vitamin B12, and Homocysteine
Alberg et al.
Cancer Epidemiol. Biomarkers Prev. 2000;9:761-764.
ABSTRACT | FULL TEXT  

Folate Is Not What It Is Cracked Up to Be
Cembrowski et al.
Arch Intern Med 1999;159:2747-2747.
FULL TEXT  

Laboratory Diagnosis of Vitamin B12 and Folate Deficiency
Rice
Arch Intern Med 1999;159:2746-2747.
FULL TEXT