Hyperhomocysteinemia and B-vitamin deficiencies in infants and children
Ueland, P.M.; Monsen, A.L.B.ør.
Clinical Chemistry and Laboratory Medicine 41(11): 1418-1426
2003
ISSN/ISBN: 1434-6621 PMID: 14656020 DOI: 10.1515/cclm.2003.218Document Number: 238942
Measurement of total homocysteine (tHcy) in healthy and diseased children has documented the utility of this marker in pediatric research and diagnostics. This article focuses on novel data obtained in infants, children and adolescents, with emphasis on cobalamin status in infants. In children, determinants of plasma tHcy are similar to those established in adults, and include age, gender, nutrition, B-vitamin status, and some drugs interfering with B-vitamin function. In infants (age < 1 year), tHcy is moderately elevated and related to serum cobalamin, whereas in older children and throughout childhood, plasma tHcy is low (about 60% of adult levels), and folate status becomes a strong tHcy determinant. As in adults, hyperhomocysteinemia in childhood is a risk factor for stroke, and folate-responsive hyperhomocysteinemia has been detected in children with renal failure. tHcy seems to be a sensitive indicator of folate deficiency in children on a poor diet, in HIV-infected children, and in children treated with anti-folate drugs. In children at increased risk of cobalamin deficiency, which includes children born to vegetarian mothers or children in developing countries on a poor diet, tHcy and methylmalonic acid are responsive indicators of a deficiency state. In newborns and infants born to mothers with an adequate nutrition, there are consistent observations of low cobalamin, elevated tHcy and methylmalonic acid, and reduction of both metabolites by cobalamin supplementation. These data have raised the question whether cobalamin deficiency may be widespread and undetected in babies born to non-vegetarian women on a Westernized diet.