Diagnosis and Effect of Folate and Vitamin B12 Deficiency

Leigh Ann Martin

Advisor: Gilbert A. Boissonneault, PhD, PA-C, CN

Background

Vitamins Organic compounds that act as metabolic

catalysts Two groups fat-soluble and water-soluble

Focus of today’s presentation: folate and vitamin B12 Water-soluble vitamins important in the

formation of red blood cells, the nervous system, and DNA

Pathophysiology

Folic acid and vitamin B12

Required for DNA synthesis and red cell maturation Two vitamins combine in methionine synthase reaction Methyl group is transferred to homocysteine to make methionine Decrease in either leads to increase in homocysteine level Premature Coronary Artery Disease Peripheral Vascular Disease

Pathophysiology

Deficiency leads to change in RBC shape Megaloblastic anemia is a subgroup of macrocytic

anemias Megaloblastic erythropoiesis when defect in DNA synthesis and

the cells are arrested at the G2 phase Becomes a buildup of cells that do not synthesize DNA so

nucleus develops at a slower rate than the rest of the cell Cytoplasm continues to grow due to RNA synthesis Cells become larger and megalblastic

Effects on the Body---Folate

Main manifestations glossitis, symptoms of anemia (weakness, pallor, shortness of

breath), and GI problems (weight loss and infertility)

Lab work an increase in MCV-- larger than 96 fL

Best test for folate levels is the red blood cell level this is the level in tissues and is not affected by recent intake

Recommended intake of folate for adults is 400 micrograms per day, and for women of childbearing age is 600 micrograms per day

Effects on the Body—vitamin B12

Main manifestations same as those for folate but may be a more serious presentation

with peripheral neuropathy, degeneration of the spinal cord, or demyelination of white matter of brain

Patient may present with difficulty walking, parasthesia, loss of memory function, and a positive Romberg test

Lab work also shows an increase in size of MCV

Recommended intake of vitamin B12 for adults is 2.4 micrograms per day, and for women of childbearing age is 2.6 micrograms per day

Anticonvulsant drugs and folate deficiency

Recent Drug Study Epileptic patients split into control and experimental group Experimental group using Phenytoin, Carbamazepine, and

Valproic Acid

Patients taking the antiepileptic medications had increased homocysteine levels and decreased red blood cell levels of folate

Different Drugs No difference in level of homocysteine between all drugs Phenytoin shown to have lowest folic acid level

Hyperhomocysteinemia

Folate deficiency is number one cause Hyperhomocysteinemia is less than 12

micromoles per liter Closely related to CVD

American Heart Association reported that 47% of all patients with CVD had hyperhomocysteinemia

Treatment

Distinguishing between the two vitamin deficiencies

Treatment is to supply the vitamin

Conclusion

Both deficiencies present very much alike

Important to distinguish between the two

Monitor patients on anticonvulsants

References

Wickramsinghe SN. Diagnosis of megaloblastic anemias. Blood Reviews. 2006; 20 (6), 299-318

Porth C. Essentials of Pathophysiology: concepts of altered health status. Second Edition. Lippincott Williams and Wilkins. 2004; 168-169.

Dale DA, Federman DA, Antman KA, Atkinson JO, Cassel CH, Feldman MA et al. ACP Medicine. Volume 1. 2006 Edition. New York: WebMD Inc; 2006.

Carmel RA. Laboratory Diagnosis of Megaloblastic Anemia. Medical Progress. 1978 April;128(4):294-304.

Sener UF, Zorlu YA, Karguzel OG, Ozdamar OZ, Coker IS, et al. Effects of common anti-epileptic drug monotherapy on serum levels of homocysteine, Vitamin B12, folic acid and Vitamin B6. Seizure. 2006 Aug 24; 15: 79-85.

Sadeghian SA, Fallahi FA, Salarifar MO, Davoodi GH, Mahmoodian ME, Fallah NA, et al. Homocysteine, vitamin B12 and folate levels in premature artery disese. BMC Cardiovascular Disorders. 2006 Sept 26; 6: 38.