The pathophysiology of elevated vitamin B12 in clinical practice.

نویسندگان

  • E Andrès
  • K Serraj
  • J Zhu
  • A J M Vermorken
چکیده

Hypercobalaminemia (high serum vitamin B12 levels) is a frequent and underestimated anomaly. Clinically, it can be paradoxically accompanied by signs of deficiency, reflecting a functional deficiency linked to qualitative abnormalities, which are related to defects in tissue uptake and action of vitamin B12. The aetiological profile of high serum cobalamin predominantly encompasses severe disease entities for which early diagnosis is critical for prognosis. These entities are essentially comprised of solid neoplasms, haematological malignancies and liver and kidney diseases. This review reflects the potential importance of the vitamin B12 assay as an early diagnostic marker of these diseases. A codified approach is needed to determine the potential indications of a search for high serum cobalamin and the practical clinical strategy to adopt upon discovery of elevated cobalamin levels. While low serum cobalamin levels do not necessarily imply deficiency, an abnormally high serum cobalamin level forms a warning sign requiring exclusion of a number of serious underlying pathologies. Functional cobalamin deficiency can thus occur at any serum level.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Reduction of Serum Vitamin B12 Levels among the Female Patients with Breast Cancer (Case Study: Sulaimania city- Iraq)

Background and objectives: Breast carcinoma is one of the most common malignant diseases among women worldwide. In Iraq there are noticeable elevation in incidence rates and prevalence of advanced stages of breast cancer. Cobalamin (vitamin B12) is essential micronutrient involved in one carbon metabolism and DNA methylation, which affects cancer. All of these may be change in breast cancer. Th...

متن کامل

Does Short-Term Low-Dose Methotrexate Treatment Affect Homocysteine Blood Level in Patients with Psoriasis?

Background: An elevated homocysteine level is an independent risk factor for cardiovascular disorders. Psoriatic patients have an increased risk of cardiovascular diseases; In addition, hyperhomocysteinemia is a complication of methotrexate treatment. We undertook a study to evaluate the plasma levels of homocysteine, vitamin B12 and folate in patients with psoriasis before and after short-term...

متن کامل

Effects of Vitamin B12 in Neonates and Young Infants

Vitamin B12 (cobalamin) is an essential coenzyme for nucleic acid synthesis. Animal protein is the major dietary source of vitamin B12. Deficiency of vitamin B12 leads to megaloblastic anemia, degeneration of the brain, spinal cord, peripheral nerves, and abnormalities of epithelial tissues. Two factors are necessary for the cure of megaloblastic anemia: one in food (extrinsic factor) and one i...

متن کامل

Vitamin B12 supplementation in end stage renal diseases: a sys-tematic review

  Background :Hyperhomocysteinemia is a risk factor for cardiovascular disease particularly in patients with end stage renal disease (ESRD). Vitamin B12 supplementation on its own still remains as a controversial issue for clinicians in decreasing the level of homcysteine in this group of patients.   Methods : Using all randomized controlled trials (RCTs), clinical trials and pre-post-trial stu...

متن کامل

بررسی سطح هموسیستیین تام

Introduction: Elevated plasma total homocysteine is an independent risk factor for cardiovascular disease and a sensitive marker of vitamin B12 and folate insufficiency. Folate and vitamin B12 have a protective effect on cardiovascular disease. This effect may be partly explained by mechanisms independent of homocysteine. This survey is the first population based study to evaluate the plasma ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • QJM : monthly journal of the Association of Physicians

دوره 106 6  شماره 

صفحات  -

تاریخ انتشار 2013