Impact of Vitamin B-12 Deficiency During Lactation on Maternal and Infant Health
Vitamin B-12 is a “cobalamin”, a term that describes structures with a corrin ring which has a central cobalt atom, phosphate, a base, and ribose. One of several groups can be attached to the cobalt: cyanide, forming vitamin B-12; 5’deoxyadenosine, forming 5’ deoxyadenosylcobalamin; or a methyl group, forming methylcobalamin. Methylcobalamin is a cofactor for the conversion of homocysteine to methionine, and adenosylcobalamin is required for the conversion of methyl malonyl CoA to succinyl CoA. These cofactor functions explain why in vitamin B-12 deficiency there is elevated methylmalonic acid (MMA) in urine and serum, and plasma homocysteine (Hcy).
KeywordsAnemia Folate Homocysteine Gastritis Thiamin
Unable to display preview. Download preview PDF.
- 1.Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin,Vitamin B-6,Folate,Vitamin B-12, Pantothenic Acid, Biotin and Choline (National Academy Press, Washington D.C., 1998).Google Scholar
- 2.L.H. Allen. Vitamin B-12 metabolism and status during pregnancy, lactation and infancy, in: Nutrient Regulation during Pregnancy, Lactation and Infant Growth, edited by L.Allen, J.King and B. Lonnerdal, pp. 173–186, (Plenum Press, New York, 1994).Google Scholar
- 3.A.L. Luhby, J.M. Cooperman, A.M. Donnenfeld, J.M. Herrero, D.N. Teller, and J.B. Wenig. Observations on transfer of vitamin B-12 from other to fetus and newborn, Am. J. Dis. Child. 96:532–533.Google Scholar
- 4.Y. Adkins and B. Lonnerdal. High affinity binding of the transcobalamin II-cobalamin complex and expression of haptocorrin by human mammary epithelial cells, Biochim. Biophys. Acta (submitted).Google Scholar
- 5.Y. Adkins. The Role of Haptocorrin in Vitamin B-12 Nutrition in Infancy, PhD Thesis, Department of Nutrition, University of California, Davis, 2000.Google Scholar
- 8.A.K. Black, L.H. Allen, G.H. Pelto, M.P. de Mata, and A. Chavez. Iron, vitamin B-12 and folate status in Mexico: associated factors in men and women and during pregnancy and lactation, Am. J. Clin. Nutr. 124:1179–1188, 1994.Google Scholar
- 11.S.M. Graham, O.M. Arvela, and G.A. Wise. Long-term neurologic consequences of nutritional vitamin B-12 deficiency in infants, J. Pediatr. 121:710–714.Google Scholar
- 13.P.C. Dagnelie, W.A. F.J.V.R.A. Vergote, J. Burema, M.A. van’t Hof, J.D. van Klaveren, and J.G.A.J. Hautvast. Nutritional status of infants aged 4 to 18 months on macrobiotic diets and matched omnivorous control infants: A population-based mixed-longitudinal study, Eur. J. Clin. Nutr. 43:325–338, 1989.PubMedGoogle Scholar