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Editor,—Before recommending periconceptional folic acid-containing multivitamin supplementation universally for the prevention of neural tube defects one would also want to be sure that it was doing no harm. A UK study showed the over-representation of worries and anxiety among children at age 7–10 years born to mothers with periconceptional multivitamin supplementation.1 In our previous study based on a short term postnatal follow up of 3356 infants (mean age 11 months) born to mothers supplemented with multivitamin or placebo-like trace element2 in the periconceptional period, the results of the tests of mental and behavioural development were similar in the two groups. However, atopic dermatitis was found more often in the multivitamin group. We now summarise the results of long term follow up to the ages of 2 and 6 years with respect to the occurrence of atopic dermatitis (and other allergies) and anxiety.
The children were born to mothers who had been supplemented with multivitamin (including 0.8 mg of folic acid) or trace elements in the Hungarian randomised, double blind, controlled trial.3Altogether 200 case and 200 control children were randomly selected with equal sex distribution for each age group (2 and 6 years) and they were examined by a double blind method. Of the 800 invited children, 625 (78%) took part in the study, 336 (84%) in the 2 year and 289 (72%) in the 6 year age groups. Parents of 120 children did not want to participate, 44 families had a new unknown address, three children died after the short term follow up study, four had severe congenital abnormalities, and four were unable to cooperate at the psychometric behavioural examinations. The occurrence of atopic dermatitis based on a medically documented case history did not differ significantly between the two nutritional groups at 2 years (32/176 (18.2%) in the multivitamin and 19/160 (11.9%) in the trace element group) and at 6 years (12/147 (8.2%) v 11/142 (7.7%)). The occurrence of other allergies including bronchial asthma, obstructive bronchitis, pseudocroup and food allergies were similar in the two nutritional groups at 2 years (21.0% in the multivitamin and 29.4% in the trace element) and at 6 years (30.6% v 33.8%).
At 2 years of age, developmental quotient was measured by the Brunet-Lezine method, while at 6 years intelligence quotient was measured by the Budapest Binet and Raven tests. In addition, the Goodenough man drawing test was used. There was no significant difference in the mental development of children between the multivitamin and trace element groups. Anxiety was measured by the child version of thematic aperception test4 in 6 year old children. Five levels of anxiety were examined but ‘extremely low’ did not occur, while ‘extremely high’ was found only in two children of the trace element group. The proportion of children scoring ‘above average’ levels of anxiety was not higher in the multivitamin group and we were thus unable to confirm the previous UK finding.
In conclusion, no adverse effect was observed in children whose mothers had received periconceptional multivitamin supplementation.