Table 5: Tailored Diagnostic Approach for Vitamin B12 Deficiency.
| Problem | Goal | Suggested Tests |
|---|---|---|
| Patient with mild to severe hematologic or neurologic signs or symptoms, or both | Confirm suspected vitamin B12 deficiency | Serum B12 |
Patient with hematologic or neurologic signs or symptoms, or both, unlikely due to vitamin B12 deficiency | Ensure if vitamin B12 deficiency exists, it is not missed | Serum B12 MMA* and HCY† |
| Asymptomatic patient with condition known to cause vitamin B12 deficiency | Determine if vitamin B12 deficiency has developed yet | MMA (metablic changes often precede low cobalamin levels) |
| Asymptomatic patient accidentally found to have low B12 level or high Hcy† | Determine if vitamin B12 deficiency exists | MMA |
*MMA - methylmalonic acid
†Hcy-homocysteine
Contact Us:
- Centers for Disease Control and Prevention
National Center on Birth Defects and Developmental Disabilities
Division of Birth Defects and Developmental Disabilities
1600 Clifton Road
MS E-87
Atlanta, GA 30333 - 800-CDC-INFO
(800-232-4636)
TTY: (888) 232-6348
New Hours of Operation
8am-8pm ET/Monday-Friday
Closed Holidays - cdcinfo@cdc.gov



