Medical Specialty >> Hematology

Doctors Lounge - Hematology Answers

Back to Hematology Answers List

If you think you may have a medical emergency, call your doctor or 911 immediately. Doctors Lounge ( does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Site.

DISCLAIMER: The information provided on is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her physician. Please read our 'Terms and Conditions of Use' carefully before using this site.

Date of last update: 10/12/2017.

Forum Name: Hematology Topics

Question: b12 and folate levels

 sarugli - Fri Jun 11, 2010 3:20 am

I have been having health problems for some time, but also mental problems. I keep getting paranoid, also my memory is not as good as it was. I scored moderate short-term memory loss on a quiz.I get frequent tachycardia, my resting heart rate can be 115 bpm sometimes.I feel very tired.
I have had different blood tests to see what the problem is, including b12 and folate.
My b12 was 306 pg/ml ( normal range 179-1132). My folate was 5.3 ng/ml ( normal range 3-19). The lab just said that's ok.
I have read on the internet though on many sites, that the levels i have of both b12 and folate can still cause lots of problems, that you can still have a deficiency and nerve and psychological problems. The sites advise to check homocysteine levels, and mma. Thing is, i feel embarrassed to go back again to have more tests, i'm living in greece, and they even thought checking b12 and folate was strange because my cbc was normal. I have quite high hb, the lab doesn't differentiate with males and females on the range, mine was 15.7 gr/ mcv is 93.5.I am female.
Don't really know what to do at this point. regards.
 Dr.M.Aroon kamath - Mon Aug 09, 2010 12:32 pm

User avatar Hi,

Vitamin B12 (Cobalamin) is a collective term for four of the chemical forms of vitamin B-12,
- cyanocobalamin (most common form in food supplements, perhaps the weakest form),
- methylcobalamin (most potent, neuroprotective function),
- hydroxycobalamin, a precursor to methylcobalamin and adenosylcobalamin. Found in animal protein but not in vegetables. Most stable form(helps in detoxification- esp; cyanide), and
- adenosylcobalamin (synthesis of nucleoproteins,and myelin in nerves).

Optimal serum levels of cobalamin are essential to complete the following three enzymatic reactions.
- Methylcobalamin acts as a cofactor in the conversion of homocysteine (Hcy) to methionine.
- The adenosylcobalamin is required for the conversion of methylmalonyl coenzyme A to succinyl coenzyme A.
- Methylcobalamin is necessary for the conversion of 5-methyltetrahydrofolate to tetrahydrofolate and is essential for DNA synthesis and red blood cell synthesis.

Deficiencies of cobalamin and folic acid result in elevations of Hcy and methylmalonic acid (MMA) levels.Studies have shown that this elevation occurs much before the fall in serum levels of vitamin B12 and folic acid.

Clinical cobalamin deficiency: manifests with hematologic or neurologic signs and symptoms, cobalamin levels <200 picograms per milliliter (pg/mL), and elevated
Hcy and methylmalonic acid (MMA) levels.

Subclinical cobalamin deficiency: no obvious clinical signs or symptoms (although some individuals might have subtle neurologic signs), cobalamin levels of 200–350 pg/mL and at least one metabolic abnormality (mildly elevated methylmalonic acid or homocysteine).

Low status of vitamin B12 and folate and increased plasma Hcy have been found in studies conducted on patients with depression. An association between depression and low levels of the two vitamins is found in some studies in the general population. Low plasma or serum folate has also been identified in patients with recurrent mood disorders treated by lithium. A link between depression and low folate has similalrly been found in patients with alcoholism. Low folate levels are furthermore linked to a poor response to antidepressants, and treatment with folic acid is shown to improve response to antidepressants.

In a large population study from Norway, vitamin B12 and folic acid deficiency was associated with increased risk of depression but not anxiety.
The authors conclude thus; “There is now substantial evidence of a common decrease in serum/red blood cell folate, serum vitamin B12 and an increase in plasma homocysteine in depression. Furthermore, the On the basis of current data, we suggest that oral doses of both folic acid (800 µg daily) and vitamin B12 (1 mg daily) should be tried to improve treatment outcome in depression”.
(J Psychopharmacol January 2005 vol. 19 no. 1 59-65)

In another study, 3,884 elderly people were screened for depressive symptoms. Folate, vitamin B(12), and homocysteine blood levels were compared in 278 persons who were diagnosed with depressive symptoms.
Concluding remarks of the authors is as follows. “The association of vitamin B(12) and folate with depressive disorders may have different underlying mechanisms. Vitamin B(12) may be causally related to depression, whereas the relation with folate is due to physical comorbidity”.
(“Vitamin B12, folate, and homocysteine in depression”: the Rotterdam Study.
Am J Psychiatry. 2002 Dec;159(12):2099-101)

People with Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism exhibit impaired homocysteine metabolism(elevated levels of homocystine). This polymorphism is more frequently seen in depressive patients in the general population. This gives credence to the association between vitamin B12 deficiency and depression.
(MTHFR) C677T polymorphism also has been seen to increase the overall risk of schizophrenia and severity of negative symptoms.

In the light of these and several other studies, it is quite understandable that your apprehensions are well founded.You can discuss with your psychiatrist about having your RBC folate, Hcy and MMA levels checked, just to be sure. RBC folate levels are more accurate than serum folate levels.
Best wishes!

| Check a doctor's response to similar questions

Are you a Doctor, Pharmacist, PA or a Nurse?

Join the Doctors Lounge online medical community

  • Editorial activities: Publish, peer review, edit online articles.

  • Ask a Doctor Teams: Respond to patient questions and discuss challenging presentations with other members.

Doctors Lounge Membership Application

Tools & Services: Follow DoctorsLounge on Twitter Follow us on Twitter | RSS News | Newsletter | Contact us