Homocysteine, folic acid and vitamin B12 in relation to pre- and postnatal health aspects.

Studies linking hyperhomocysteinemia (HHCY) and B-vitamin deficiency to some health aspects in children have been accumulating. Low B-vitamin status inearly life, even as early as the time of conception, may endanger the potential for new life and may negatively influence the health of the offspring. Early abortion, pregnancy complications and poor pregnancy outcomes have been linked to elevated concentrations of total plasma homocysteine (tHcy) and low folate or vitamin B12. Maternal vitamin status predicts that of fetuses and neonates. Lactating women are likely to experience low micronutrient status, which might affect breast-milk composition and hence the nutritional status of their breast-fed infants. Elevated concentrations of methylmalonic acid (MMA) is common in infants (age <6 months), which may indicate a transient inadequate vitamin B12 status. Deficiency of B-vitamins might confer deleterious effects on the physical and mental health of the child, such as impaired growth, gross motor function, poor school performance and other adaptive skills. The importance of maintaining adequate B-vitamin status during periods of progressive growth and development should be emphasized because symptoms related to folate and vitamin B12 deficiency are difficult to detect. Serum levels of tHcy and MMA should be estimated in several target groups of children, pregnant and lactating women and those planning for pregnancy. Concentrations of tHcy and MMA are useful indicators of B-vitamin status in the pediatric laboratory. Using these functional markers may facilitate detecting sub-optimal B-vitamin status in children.