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The Welfare Food Scheme has recently been reviewed, and, although changes are being made, free vitamin supplements for children <4 years old will remain an important part of the new "Healthy Start" scheme. Establishing precise daily requirements for vitamins is not easy, and there is considerable individual variation; however, achieving the reference nutrient intake (RNI) should be possible with a healthy balanced diet for all except vitamins K and D, which require additional physiological or metabolic processes. For vitamin K, there is a well-established neonatal supplementation programme, and clinical deficiency is extremely rare. For vitamin D, however, supplementation is inconsistent, and both clinical and subclinical deficiencies are not uncommon in young children in the UK, particularly infants of Asian and Afro-Caribbean ethnic origin, and those who have prolonged exclusive breast feeding and delayed weaning. Most vitamin supplements contain vitamins A, C and D, with or without some of the B group of vitamins. There is clinical and dietary evidence to support vitamin D supplementation and some evidence from dietary surveys that vitamin A intakes may be low; however, there is no evidence to support supplementation of diets of UK children with water-soluble vitamins. Future strategy should aim at education of the public and health professionals regarding dietary intake and physiological aspects of vitamin sufficiency, as well as increasing awareness and availability of supplements, particularly of vitamin D, for those at increased risk of deficiency.

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The pharmacokinetics of once-a-day netilmicin (4.5 mg/kg) was studied in 16 neonates, divided for analysis into three groups according to gestational age: group 1 >36 weeks (n=7); group II between 34-36 weeks (n=4); and group III <34 weeks (n=5). The serum netilmicin (mean +/- SD) 4h and 24h after the first dose were 4.7 +/- 0.8 and 0.8 +/- 0.5 mg/L; 4.9 +/- 0.8 and 1.9 +/-0.2 mg/L; 4.9 +/- 0.5 and 1.7 +/- 0.5 mg/L in groups I, II and III respectively. After the second dose, concentrations at 2, 4, 8, 16 and 24 h were 7.2 +/- 1.0, 5.0 +/- 0.8, 3.0 +/- 0.6, 1.7 +/- 0.4 and 0.9 +/- 0.2 mg/L (group I); 8.6 +/- 0.2, 6.1 +/- 0.5, 4.2 +/- 0.7, 2.6 +/- 0.1 and 1.4 +/- 0.4 mg (group II); 9.0 +/- 1.2, 6.3 +/- 0.9, 4.1 +/- 0.7, 2.6 +/- 0.5 and 1.7 +/- 0.3 mg/L (group III). There was a large degree of inter-patient variability in serum concentrations and serum half-life (t1/2), volume of distribution (VD), area-under-the-curve (AUC), relative serum clearance (Clp) such that these parameters could not be correlated to age or weight. Absolute serum clearance (L/h) was correlated with gestational age (r = 0.672, P <0.01). There was no statistically significant evidence of accumulation between the first and second doses for any patient group. One baby from each group II and group III had concentration >2 mg/L 24h after the first dose and one baby from group III had concentration >2 mg/L 24h after the second dose. There are no established correlations between serum netilmicin concentrations and efficacy or toxicity in neonates and keeping 24 h trough concentration below 2 mg/L with a once-a-day dose of 4.5 mg/L would have to be validated in terms of its clinical efficacy and potential toxicity in a neonatal population.

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In a comparative study in term, preterm and low-birthweight infants, the mean activity and standard error of the mean for copper/zinc superoxide dismutase (Cu/Zn SOD) in cord erythrocytes from five term small for gestational age infants was 0.94 +/- 0.10 SOD units (mg protein)-1. This value was significantly lower than the activity (2.34 +/- 0.24) in nine term, appropriate for gestational age (AGA) babies (p < 0.005). In 15 preterm (AGA) infants, the activity at birth (1.05 +/- 0.07 SOD units (mg protein)-1) was also significantly lower (p < 0.001) relative to term AGA babies. An increased level of activity (1.59 +/- 0.09) was detected in the red cells of eight preterm AGA infants on their expected date of delivery compared with (0.87 +/- 0.06) at birth (p < 0.001). However, the activity (1.59 +/- 0.09) was still lower than that detected in term AGA babies (2.34 +/- 0.24; p < 0.02). Similar findings were obtained when enzymatic activity was expressed in units per millilitre of packed erythrocytes. The low activity of Cu/Zn SOD in preterm and low-birthweight babies may render them susceptible to diseases associated with membrane lipid peroxidation.

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Electroretinograms (ERGs) and visual evoked potentials (VEPs) to flash stimulation were recorded from 51 infants (gestational age 26 to 42 weeks; post-conceptional age (PCA) 31 to 47 weeks) to give cross-sectional data on the maturation of these responses. Sequential recordings were taken from a separate group of 24 preterm infants (gestational age 28 to 33 weeks) to give longitudinal data. There was a significant decrease in ERG a-wave latency and increase in a-b amplitude with increasing PCA in both groups. For the VEPs there was a significant decrease in latency of the early negative component (N1) and the major positive component (P2). Comparison between recordings made on preterm infants with those from term infants at an equivalent PCA suggested faster maturation of VEPs in the extra-uterine environment, but no difference in maturation of the ERG.

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Long chain polyunsaturated fatty acid composition of plasma choline phosphoglycerides has been measured at birth in 22 preterm infants. Positive correlations were found between both n-6 and n-3 fatty acids and measurements of growth and maturation. 20:4(n-6) and the sum of 20:3(n-6) + 20:4(n-6) correlated most strongly with weight and head circumference, while 22:6(n-3) showed strongest correlation with length of gestation. These findings are of relevance to understanding the role of nutrition in fetal growth and in establishing the group of infants most at risk of postnatal deficiency of essential fatty acids.

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Long-chain polyunsaturated fatty acid (LCPUFA) composition of choline phosphoglycerides was measured in the plasma of 22 preterm infants at birth and at expected date of delivery (EDD). In a subgroup of 10 infants, data were also collected at regular intervals between birth and EDD. Levels at birth showed a positive correlation between arachidonic acid (AA) and birth weight, p less than 0.01, and between docosahexaenoic acid (DHA) and gestational age, p less than 0.01. Percentage compositions of both AA and DHA fell rapidly between preterm birth and expected date of delivery, at a time when they would remain high in utero. For AA, the mean value fell from 16.52 to 7.18%, and for DHA from 4.49 to 2.63%. Levels of DHA fell less in babies fed breast milk than in those fed formula milk, p less than 0.05, and levels of AA fell less in those requiring a large number of blood transfusions, p less than 0.05. The level of DHA fell more in those infants with intrauterine growth retardation, p less than 0.05. Although these nutrients share common metabolic pathways for their synthesis, they appear to be affected by different factors in both the fetus and the preterm infant. Low levels at this time may adversely affect brain and retinal development.

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Hypothalamic-pituitary function was studied in four children with Optic Nerve Hypoplasia (ONH). All were found to be growth hormone deficient when provoked with glucagon or insulin induced hypoglycaemia (ITT), but did respond to bolus injection of GHRH. This indicates a primary hypothalamic defect. Virtual absence of pituitary tissue on high resolution CT scan explained the poor response of one child. One child has shown an excellent response to treatment with subcutaneous GHRH, which is physiologically the most appropriate treatment for this condition.

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