Vitamin B12 found in animal foods acts as cofactor in two enzyme systems in the human body. Vitamin B12 shows the majority of its physiological effects via to its contribution to the homocysteine methionine cycle. Vitamin B12 deficiency is mostly caused by disorders related to absorption mechanisms and is associated with many diseases primarily neurological and hematological diseases. Due to the large measurement uncertainty, serum vitamin B12 levels should be determined as well as homocysteine levels. Finally, parenteral treatment approaches is accepted as a more accurate method in vitamin B12 deficiency.
(4). Soysal T. Anemiler, DÜ Cerrahpaşa Tıp Fak. Sürekli Tıp Eğitimi Etkinlikleri, Anemiler Sempozyumu, 2001; 33-47.
(5). Johnson BS. Antianemic and Hematopoietic Stimulating Drugs. Pharmacology and Therapeutics for Dentistry. 7th Edition. Mosby, 2017:;358–70.
(6). Obeid R, Fedosov SN, Nexo E. Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention or treatment of cobalamin deficiency. Mol Nutr Food Res 2015; 59: 1364-72.
(7). Dikmen M. Molecular biology of methylenetetrahydrofolate reductase (MTHFR) enzyme and its association with diseases. The Medical Journal of Kocatepe 2004; 5: 9-16.
(8). Green R. Vitamin B12 deficiency from the perspective of a practicing hematologist. Blood 2017; 129: 2603-11.
(9). Takemoto C, Spremulli LL, Benkowski LA, et al. Unconventional decoding of the AUA codon as methionine by mitochondrial tRNAMet with the anticodon f5CAU as revealed with a mitochondrial in vitro translation system. Nucleic Acids Res 2009; 37(5): 1616-27.
(10). Yin J, Li T, Yin Y. Methionine and antioxidant potential. Journal of Antioxidant Activity 2016; 1(2): 17-22.
(12). Mansoor MA, Bergmark C, Svardal AM. Redox status and protein binding of plasma homocysteine and other aminothiols in patients with early-onset peripheral vascular disease. Arterioscler Thromb Vasc Biol 1995; 15: 232-40.
(13). Stamler JS, Osborne JA, Jaraki O. Adverse vascular effects of homocysteine are modulated by endothelium-derived relaxing factor and related oxides of nitrogen. J Clin Invest 1993; 91:308-18.
(14). Nappo F, De Rosa N, Marfella R. Impairment of endothelial functions by acute hyperhomocysteinemia and reversal by antioxidant vitamins. JAMA 1999; 281: 2113-8.
(15). Lentz SR, Sadler JE. Inhibition of thrombomodulin surface expression and protein C activation by the thrombogenic agent homocysteine. J Clin Invest 1991; 88: 1906-14.
(16). Rodwell VW, Bender DA, Botham KM, et al. Micronutrients: Vitamins & Minerals, Harper’s Illustrated Biochemistry, 30th Edition. The McGraw-Hill Companies, 2015; 546-63.
(17). Ede G, Ayaz A. The Effect of Vitamin B12 and folic acid on adiposity. Bes Diy Derg 2016: 44(1): 47-54.
(18). Dali-Youcef N, Andres E. An update on cobalamin deficiency in adults. QJM 2009; 102(1): 17-28.
(19). Allen LH. How common is vitamin B12 deficiency. Am J Clin Nutr 2009; 89:693-6.
(20). Fidancı İ, Eren ŞÜ, Arslan İ, et al. Aile hekimliği poliklinik hastalarının son 3 yıl retrospektif değerlendirilmesi. Konuralp Tıp Dergisi 2016; 8(3): 151-7.
(21). Dharmarajan TS, Norkus EP. Approaches to vitamin B12 deficiency; early treatment may prevent devastating complications. Postgraduate Med 2001; 110: 99-105.
(22). Oh RC, Brown DL. Vitamin B12 deficiency. Am Fam Physician 2003; 67(5): 993-4.
(23). Avcı Z, Turul T, Aysun S. Involuntry movements and magnetic resonance imaging findings in infantile cobalamin. Pediatrics 2003; 112(3): 684.
(24). Avşar AFY, Taş EE, Akçay GY. B12 Vitamini ve infertilite. Ankara Medical Journal 2013; 13(2): 82-4.
(25). Zhang T, Xin R, Gu X, et al. Maternal serum vitamin B12, folate and homocysteine and the risk of neural tube defects in the offspring in a high-risk area of China. Public Health Nutrition 2008; 12(5): 680-6.
(26). Pinhas-Hamiel O, Doron-Panush N, Reichman B, et al. Obese children and adolescents, a risk group for low vitamin B12 Concentration Arch Pediatr Adolesc Med 2006; 160: 933-6.
(27). Karatela RA, Sainani GS. Plasma homocysteine in obese, overweight and normal weight hypertensives and normotensives. 2009; 61(2) :156-9.
(28). Sönmez CI, Baltacı D, Deler MH. Aşırı kilolu ve obez olgularda vitamin B12 ve vitamin D seviyelerinin değerlendirilmesi. J Fam Med 2015; 4(1): 8.
(29). Sezgin Y, Becel S. Comparison of serum lipid parameters and serum vitamin B12 levels. J Clin Anal Med 2019; 10(2): 198-201.
(30). Sezgin Y, Becel S. Evaluation of Lipid Parameters in Patients Receiving Vitamin B12 Therapy. İstanbul Med J 2019; 20(3): 214-7.
(31). Sezgin Y, Kılıç MA, Günvar T, et al. Mouth and eye dryness after use of sildenafil: A case report. Euras J Fam Med 2015; 4(2): 94-6.
(32). Sezgin Y, Kartal M, Güldal AD. A comparison of serum alpha-1-antitrypsin and vitamin B12 levels in patients with vitamin B12 deficiency. Clin Anal Med 2018; 9(3): 192-4.
(33). Pagan K, Hau J, Goldenberg RL,Cliver SP, Tamura T. Effect of smoking on serum consentrations of total homocysteine and B vitamins in mid-pregnancy. Clinica Chimica Acta 2001; 306: 103-9.
(34). Pivathilake HJ, Macaluso M, Hine RJ, et al. Local and systemic effects of cigarette smoking on folate and vitamin B12. Am J Clin Nutr 1994; 60: 559-66.
(35). Mcgarry JM, Andrews J. Smoking in pregnancy and vitamin B12 metabolism. British Medical Journal 1972; 2: 74-7.
(36). Linnell,JC, Smith ADM, Smith CL, et al. Effects of smoking on metabolism and excretion of vitamin B12. British Medical Journal 1968; 2: 215-6.
(37). Carmel R. How I treat cobalamin (vitamin B12) deficiency. Blood 2008; 112(6): 2214-21.
Vitamin B12 Yetersizliğine Yaklaşım
Year 2019,
Volume: 11 Issue: 3, 482 - 488, 23.10.2019
Hayvansal gıdalarda bulunan vitamin B12; insan vücudunda iki enzim sisteminde kofaktör olarak görev alır. Vitamin B12 fizyolojik etkilerinin çoğunluğunu homosistein metiyonin döngüsüne sağladığı katkı yoluyla gösterir. Vitamin B12 yetmezliği çoğunlukla emilim mekanizmaları ile ilişkili bozukluklardan kaynaklanır ve öncelikle nörolojik ve hematolojik hastalıklar olmak üzere pek çok hastalıkla ilişkilendirilir. Ölçüm belirsizliğinin geniş olması nedeniyle serum vitamin B12 seviyesinin tespit edilmesinin yanında homosistein seviyesine de bakılması gereklidir. Son olarak vitamin B12 yetersizliğinde paranteral tedavi yaklaşımı daha doğru bir yöntem olarak kabul görmektedir.
(4). Soysal T. Anemiler, DÜ Cerrahpaşa Tıp Fak. Sürekli Tıp Eğitimi Etkinlikleri, Anemiler Sempozyumu, 2001; 33-47.
(5). Johnson BS. Antianemic and Hematopoietic Stimulating Drugs. Pharmacology and Therapeutics for Dentistry. 7th Edition. Mosby, 2017:;358–70.
(6). Obeid R, Fedosov SN, Nexo E. Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention or treatment of cobalamin deficiency. Mol Nutr Food Res 2015; 59: 1364-72.
(7). Dikmen M. Molecular biology of methylenetetrahydrofolate reductase (MTHFR) enzyme and its association with diseases. The Medical Journal of Kocatepe 2004; 5: 9-16.
(8). Green R. Vitamin B12 deficiency from the perspective of a practicing hematologist. Blood 2017; 129: 2603-11.
(9). Takemoto C, Spremulli LL, Benkowski LA, et al. Unconventional decoding of the AUA codon as methionine by mitochondrial tRNAMet with the anticodon f5CAU as revealed with a mitochondrial in vitro translation system. Nucleic Acids Res 2009; 37(5): 1616-27.
(10). Yin J, Li T, Yin Y. Methionine and antioxidant potential. Journal of Antioxidant Activity 2016; 1(2): 17-22.
(12). Mansoor MA, Bergmark C, Svardal AM. Redox status and protein binding of plasma homocysteine and other aminothiols in patients with early-onset peripheral vascular disease. Arterioscler Thromb Vasc Biol 1995; 15: 232-40.
(13). Stamler JS, Osborne JA, Jaraki O. Adverse vascular effects of homocysteine are modulated by endothelium-derived relaxing factor and related oxides of nitrogen. J Clin Invest 1993; 91:308-18.
(14). Nappo F, De Rosa N, Marfella R. Impairment of endothelial functions by acute hyperhomocysteinemia and reversal by antioxidant vitamins. JAMA 1999; 281: 2113-8.
(15). Lentz SR, Sadler JE. Inhibition of thrombomodulin surface expression and protein C activation by the thrombogenic agent homocysteine. J Clin Invest 1991; 88: 1906-14.
(16). Rodwell VW, Bender DA, Botham KM, et al. Micronutrients: Vitamins & Minerals, Harper’s Illustrated Biochemistry, 30th Edition. The McGraw-Hill Companies, 2015; 546-63.
(17). Ede G, Ayaz A. The Effect of Vitamin B12 and folic acid on adiposity. Bes Diy Derg 2016: 44(1): 47-54.
(18). Dali-Youcef N, Andres E. An update on cobalamin deficiency in adults. QJM 2009; 102(1): 17-28.
(19). Allen LH. How common is vitamin B12 deficiency. Am J Clin Nutr 2009; 89:693-6.
(20). Fidancı İ, Eren ŞÜ, Arslan İ, et al. Aile hekimliği poliklinik hastalarının son 3 yıl retrospektif değerlendirilmesi. Konuralp Tıp Dergisi 2016; 8(3): 151-7.
(21). Dharmarajan TS, Norkus EP. Approaches to vitamin B12 deficiency; early treatment may prevent devastating complications. Postgraduate Med 2001; 110: 99-105.
(22). Oh RC, Brown DL. Vitamin B12 deficiency. Am Fam Physician 2003; 67(5): 993-4.
(23). Avcı Z, Turul T, Aysun S. Involuntry movements and magnetic resonance imaging findings in infantile cobalamin. Pediatrics 2003; 112(3): 684.
(24). Avşar AFY, Taş EE, Akçay GY. B12 Vitamini ve infertilite. Ankara Medical Journal 2013; 13(2): 82-4.
(25). Zhang T, Xin R, Gu X, et al. Maternal serum vitamin B12, folate and homocysteine and the risk of neural tube defects in the offspring in a high-risk area of China. Public Health Nutrition 2008; 12(5): 680-6.
(26). Pinhas-Hamiel O, Doron-Panush N, Reichman B, et al. Obese children and adolescents, a risk group for low vitamin B12 Concentration Arch Pediatr Adolesc Med 2006; 160: 933-6.
(27). Karatela RA, Sainani GS. Plasma homocysteine in obese, overweight and normal weight hypertensives and normotensives. 2009; 61(2) :156-9.
(28). Sönmez CI, Baltacı D, Deler MH. Aşırı kilolu ve obez olgularda vitamin B12 ve vitamin D seviyelerinin değerlendirilmesi. J Fam Med 2015; 4(1): 8.
(29). Sezgin Y, Becel S. Comparison of serum lipid parameters and serum vitamin B12 levels. J Clin Anal Med 2019; 10(2): 198-201.
(30). Sezgin Y, Becel S. Evaluation of Lipid Parameters in Patients Receiving Vitamin B12 Therapy. İstanbul Med J 2019; 20(3): 214-7.
(31). Sezgin Y, Kılıç MA, Günvar T, et al. Mouth and eye dryness after use of sildenafil: A case report. Euras J Fam Med 2015; 4(2): 94-6.
(32). Sezgin Y, Kartal M, Güldal AD. A comparison of serum alpha-1-antitrypsin and vitamin B12 levels in patients with vitamin B12 deficiency. Clin Anal Med 2018; 9(3): 192-4.
(33). Pagan K, Hau J, Goldenberg RL,Cliver SP, Tamura T. Effect of smoking on serum consentrations of total homocysteine and B vitamins in mid-pregnancy. Clinica Chimica Acta 2001; 306: 103-9.
(34). Pivathilake HJ, Macaluso M, Hine RJ, et al. Local and systemic effects of cigarette smoking on folate and vitamin B12. Am J Clin Nutr 1994; 60: 559-66.
(35). Mcgarry JM, Andrews J. Smoking in pregnancy and vitamin B12 metabolism. British Medical Journal 1972; 2: 74-7.
(36). Linnell,JC, Smith ADM, Smith CL, et al. Effects of smoking on metabolism and excretion of vitamin B12. British Medical Journal 1968; 2: 215-6.
(37). Carmel R. How I treat cobalamin (vitamin B12) deficiency. Blood 2008; 112(6): 2214-21.