Growth patterns of breast fed and formula fed infants in the first 12 months of life: an Italian study

AIM—To compare the growth patterns of breast fed and formula fed Italian infants in the first 12 months of life using World Health Organisation (WHO) reference data.
METHODS—The growth patterns of 73 breast fed infants (36 male, 37 female) and 65 formula fed infants (35 male, 30 female) were compared. Solid foods were introduced with the same weaning schedules from the 5th month in both groups. The weight for age (WA), length for age (LA), and weight for length (WL) z scores (National Center for Health Statistics-WHO data) were calculated at birth, 1, 2,3, 4, 6, 9, and 12months.
RESULTS—Breast fed infants had the highest z scores (WA, WL) at birth. Breast fed groups had significantly higher growth indices at 1 month (WA, LA), 2 months (WA) and 3 months (WA, LA) of age. Compared to breast fed groups, formula fed infants showed significantly higher WA z score changes in the 1-2, 2-3, 3-4, and 4-6 month intervals. LA z score changes were higher for breast fed infants at 0-1 month and for the formula fed infants at 4-6 months. In the 6-12 month interval growth indices progressively increased for the formula fed infants and declined for infants breast fed for longer (12 months). The 0-12 month changes in WA, LA, and WL z scores were positive for formula fed infants and negative for the 12 month breast fed group. Nevertheless, the 12 month breast fed group showed an absolute WA z score just below 0 (mean (SEM) −0.04 (0.26)) at 12months.
CONCLUSION—The growth pattern of breast fed and formula fed Italian infants differs in the first 12 months of life. This questions the validity of current reference values for monitoring the growth of breast fed infants. Growth indices in breast fed groups, high at birth and closer than expected to the reference at 12 months, may reflect differences in genetic factors, intrauterine conditions, or both.

     

Growth of infants with IgE-mediated cow''s milk allergy fed different formulas in the complementary feeding period

Observational studies have shown that allergic infants, irrespective of the type of diet, show various degrees of growth depression in the first year of life. We investigated whether the type of milk in the complementary feeding period (6-12 months of age) is associated with differences in the increase of standardized growth indices (weight-for-age, WA; length-for-age, LA; and weight-for-length, WL, z-scores) in infants with cow's milk allergy (CMA). Infants with immunoglobulin E-mediated CMA breastfed at least 4 months and progressively weaned in the 5- to 6-month period were randomly assigned to three special formulas, a soy formula (n = 32), a casein hydrolysate (n = 31), and a rice hydrolysate (n = 30). A fourth, non-randomized group was made up by allergic infants still breastfed up to 12 months (n = 32). Groups were compared for WA, LA, and WL z-scores at 6, 9 and 12 months of age. All groups showed low WA and LA z-scores at 6 months of age. Infants fed hydrolyzed products showed a trend toward higher WA z-score increments in the 6- to 12-month period. The use of casein- and rice-based hydrolyzed formulas resulted in higher changes in WA compared with soy formula. Further research should be aimed at optimizing the dietary needs and feeding regimens for infants with CMA.     

Anthropometric indicators of human immunodeficiency virus infection in infants with early and late symptoms in the first months of life

Standardised growth indices (Z-scores of weight-for-age, WA, length-for-age, LA, weight-for-length, WL, according to the reference data of the World Health Organization) have been compared for the first 4 months of life among 119 infants born to mothers affected by the type-1 human immunodeficiency virus (HIV). Infants were subdivided according to their HIV serostatus and the clinical expression of the disease. Uninfected status (n = 92), late (≥6 months, n = 18) and early (≤3 months, n = 9) onset of symptoms among the HIV infected defined three groups. Infants with early symptoms showed the lowest median WA and LA Z-scores at all times and the LA difference with their uninfected counterparts was already significant at birth. Infants with late symptoms showed early differences in WL and then in WA also compared with the uninfected ones. A<−0.40 LA Z-score at birth gave a 5.9 relative risk (RR) to be an infant with early symptoms (95% CI = 1.2−27.4) while a negative WL Z-score at 2 months of age gave a 4.2 RR for the HIV seropositivity (95% CI = 2.1−8.3). Conclusion Linear growth is the first parameter to be negatively affected among human immunodeficiency virus seropositive infants with early symptoms. In infants with late symptoms the lack of rapid WA and WL increase found among uninfected patients may be viewed as an early anthropometric indicator of HIV status. Received: 12 January 1998 / Accepted: 2 February 1998     

Adequacy of expressed breast milk for early gwoth of preterm infants.

Poor weight gain observed in preterm infants who were fed expressed breast milk compared with those fed a cows'' milk formular prompted a detailed study of early postnatal growth in preterm infants fed these two milks. 68 infants were divided into two categories by gestational age at birth (i) 28-32 weeks (n=28), (ii) 33-36 weeks (n=40). They were randomly allocated to a feed of expressed breast milk or a milk formula (Ostermilk 1). Rates of weight gain, linear growth, and head circumference growth were evaluated over two periods: birth-1 month, 1-2 months. The younger group who were fed breast milk showed slower overall growth rates over the first month than those fed formula. In the second month, and for the older infants over both of the 2-monthly periods, growth rates were similar in the two feeding regimens. It is concluded that expressed breast milk is inadequate for the growth of very immature preterm infants during early postnatal life.     

Growth After Neonatal Arterial Switch Operation for D-Transposition of the Great Arteries

The objective of this study was to evaluate growth in infants with d-transposition of the great arteries (d-TGA) who underwent switch operation (anatomical correction) in the early neonatal period. Growth data (at birth and 1, 3, 6, 12, and 24 months of age) were retrieved in 23 infants with d-TGA who survived the operation without major complications. Measures were transformed into z scores and compared with normative data for age. Following surgery, infants showed low z scores for weight, height, and head circumference. Weight and height showed a trend to reach normal ranges between 6 and 12 months of age, and the z scores were positive at 24 months. z scores for head circumference were still negative at 24 months of age. No dietary interventions were implemented during this period, and the infants were fed their own mothers' milk or, before discharge, high-calorie, preterm formula. Following anatomical correction for d-TGA in the early neonatal period, infant growth shows a characteristic pattern, with parameters normalized by 12 months of age in most cases. Head growth shows a different pattern, although gross motor development seems unaffected.     

Selenium status of New Zealand infants fed either a selenium supplemented or a standard formula

Objective: New Zealand soils are deficient in the essential micronutrient, selenium. New Zealand infants have low selenium levels at birth and experience a further decline if fed cows milk based formula. This study examined the selenium status of infants fed with a new commercially available selenium supplemented formula.
Methodology Forty-four newborn infants, whose mothers wished to formula feed, were randomized in an open controlled trial to be fed a commercially available selenium supplemented cows milk formula (containing 17 μg Se/L) or an unsupplemented formula (containing 4.6 μg Se/L). Cord, 1 and 3 month blood samples were obtained for selenium status (plasma and red cell selenium and glutathione peroxidase) and thyroid function.
Results Mean plasma selenium and glutathione peroxidase values were significantly higher in supplemented than unsupplemented infants at 1 month (unpaired t -tests; P <0.0001 and P = 0.001 respectively) and 3 months ( P <0.0001 and P = 0.0005). Analysis within treatment groups between time points (paired t -tests) showed that selenium supplementation prevented the fall in plasma selenium from birth to 1 month seen in unsupplemented infants and was associated with a rise in levels between 1 and 3 months ( P = 0.002).
Conclusions Supplementing cows milk formula with selenium to replicate the levels found in breast milk is nutritionally sound. Feeding from a few days of age with a formula containing 17 μg Se/L in infants with low selenium status at birth is sufficient to cause a rise to 80% of adult levels at 3 months of age.     

The growth of breast fed and artificially fed infants from birth to twelve months

Growth data collected from 394 healthy infants were analysed in relation to feeding practices. Infants were grouped on the basis of sex, if breast fed or artificially fed, and duration of breast feeding. From birth to 3 months, weight gains were similar for boys (2.5 kg) and also for girls (2.3 kg) irrespective of feeding method. From 3 to 6 months weight gains were greater in infants who were artificially fed from birth (2.0 kg both sexes) or breast fed for only a short time (1.9 kg) than for those exclusively breast fed for 6 months (1.6 kg) or longer (1.7 kg). Weight gains continued to be greater in artificially fed infants after 6 months. Over 12 months, artificially fed boys gained 410 g and girls 750 g more than those who were breast fed from birth. These differences occurred even though the artificial feedings that prevailed to 6 months and longer were low-solute ('humanized') formulas.     

Angiotensin converting enzyme activity in infancy is related to birth weight

AIMS: (a) To measure infant angiotensin converting enzyme (ACE) activity in healthy term infants at birth and during the first three months of life. (b) To determine the relation between serum ACE activity and infant feeding practice during this period. (c) To investigate the relation between serum ACE activity and birth weight and other potential contributing factors including acid-base status at birth, gestation, and maternal ACE genotype. METHODS: Prospective study of term infants, with clinical and feeding data collected from parents and medical records, and serum ACE measured in the infant at birth and 1 and 3 months of age, and in the mother at the time of birth and one to three months after birth. RESULTS: At birth and 1 and 3 months of age, infant serum ACE activity was twice that of maternal ACE activity. Infant ACE activity at birth and 1 and 3 months did not significantly differ between breast and formula fed infants. There was a highly significant negative correlation between infant ACE activity at 3 months and birth weight (r = -0.52; p < 0.001). This persisted after the conversion of birth weights to z scores (r = -0.34; p = 0.03). ACE activity at 3 months was also related to placental weight (r = -0.30; p = 0.02) and maternal age (r = -0.30; p = 0.05). The strong correlation between serum ACE activity and birth weight z score persisted after adjustment for maternal age and placental weight (r = -0.34; p = 0.03). CONCLUSION: As ACE is increasingly identified as a risk factor for cardiovascular disease, serum ACE activity in infancy may contribute to the link between low birth weight and later cardiovascular events.     

Selenium in German infants fed breast milk or different formulas

At birth and at 4 months of age, selenium (Se) values of 129 term infants on three different diets were determined: 50 infants were breast fed (HM), 44 received formula based on cow's milk (F) and 35 were fed "hypoallergenic formula" (PHF) (partially hydrolysed whey protein). The Se status of a group of twins (n = 12) fed "hypoallergenic formula" was compared with the respective group of singletons. All infants had low plasma Se values during early infancy. The plasma Se of breast-fed infants remained stable (plasma Se 438 ng/ml at birth and at 4 months), whereas plasma glutathione peroxidase (GSH-Px) decreased (birth: 10729 U/l; 4 months: 6211 U/l). The formula-fed infants showed a reduction in plasma Se levels from birth to 4 months (3810 ng/ml and 299 ng/ml, respectively). The decrease was even more pronounced in infants fed the "hypoallergenic formula". This group presented the lowest Se values (plasma Se 399 ng/ml at birth; 206 ng/ml at 4 months). Renal excretion of Se was found to be lower in the formula-fed infants (F and PHF) compared with the HM group. There was a significant correlation between plasma and urinary Se (r = 0.62, p = 0.0001). Urinary Se ($uMg Se/g creatinine) appeared to be a good indicator of Se intake. Measurements of urine Se might be used as a screening method for the estimation of the Se supply. Weight and length increases in all infants were within the normal range. There were no differences between the different feeding groups. Glutathione peroxidase activity, human milk, infant formula, infant nutrition, screening method, selenium, selenium excretion, trace elements, twins
F Jochum, Department of Paediatrics, Heinrich-Heine-University, D-40225 Dusseldorf, Moorenstrafie 5a, Geb 23.12.02, Germany     

Growth in the first two years of uninfected children born to HIV-1 seropositive mothers

OBJECTIVE—To assess the growth curves of uninfected infants born to type 1 human immunodeficiency virus (HIV-1) seropositive mothers by means of standardised anthropometric indices.
METHODS—The z scores (National Center for Health Statistics-World Health Organisation data) of weight for age, length for age, and weight for length of 92 uninfected full term infants born to HIV positive mothers were compared with those of 65 bottle fed full term infants born to healthy mothers at 0, 1, 2, 3, 4, 6, 9, 12,18, and (in a subgroup) 24 months of age. Confounders were also recorded.
RESULTS—The study population had a lower length for age z score at birth (95% confidence intervals (CI): 0.02, −0.58) and higher weight for length z scores at 1 (95% CI: 0.21, 0.63), 2 (95% CI: 0.25,0.66), and 3 (95% CI: 0.0, 0.48) months compared with the reference group. After a temporary recovery, the length for age z score difference increased progressively from the 4th month onwards and was significant at 18 (95% CI: −0.31, −1.05) and 24 (95% CI: −0.02, −0.91) months. The difference between the length for age z scores at birth was associated with maternal covariates, but the between group difference at 18 months was apparent even after adjustment for covariates.
CONCLUSION—Uninfected infants born to HIV positive mothers have a rapid weight gain immediately after birth. A decrease in length progression during the second year might be a result of the social risk connected with the family environment and an unfavourable programming related to the maternal HIV status.

     

Comparison of evoked arousability in breast and formula fed infants.

BACKGROUND: Currently, there is no consistent evidence that breast feeding reduces the risk for sudden infant death syndrome (SIDS). Arousal from sleep is believed to be an important survival mechanism that may be impaired in victims of SIDS. Previously it has been shown that arousability is impaired by the major risk factors for SIDS such as prone sleeping and maternal smoking. AIMS: To establish whether arousability was altered by method of feeding, and whether breast fed infants would have lower arousal thresholds. METHODS: Forty three healthy term infants were studied using daytime polysomnography on three occasions: 2-4 weeks post-term, 2-3 months post-term, and 5-6 months post-term. Multiple measurements of arousal threshold (cm H(2)O) in response to nasal air jet stimulation applied alternately to the nares were made in both active sleep (AS) and quiet sleep (QS) while infants slept supine. Arousal thresholds and sleep period lengths were compared between formula fed and breast fed infants at each age. RESULTS: Arousal thresholds were not different between breast fed and formula fed infants in QS. However, in AS breast fed infants were significantly more arousable than formula fed infants at 2-3 months of age. There was no difference between groups of infants when sleep period length was compared at any study. CONCLUSIONS: Breast fed infants are more easily aroused from AS at 2-3 months of age than formula fed infants. This age coincides with the peak incidence of SIDS.     

Sialic acid content of infant saliva: comparison of breast fed with formula fed infants

Sialic acid is found in especially high concentrations in brain gangliosides, and supplementary sialic acid is associated with increased learning behaviour in animals. It was hypothesised that breast fed infants may have higher concentrations of sialic acid in body fluids and tissues because human milk is a rich source of sialylated oligosaccharides, while formulas contain very little. The aim therefore was to compare the sialic acid content of saliva collected from full term infants who were either solely breast fed or formula fed until weaning at 3-5 months of age. Thirty three infants, 18 breast fed and 15 formula fed, were studied at a mean (SD) age of 5 (2) months. The breast fed infants, when compared with formula fed infants, were found to have almost two times more free sialic acid in saliva (mean (SE) 16.0 (2.7) v 8.2 (2.1) mg/l, p < 0.036) and nearly 50% more total sialic acid (47.3 (3.9) v 32.2 (4.4) mg/l, p < 0.014). The findings provide a preliminary indication that an exogenous source of sialic acids derived from human milk may contribute to higher concentrations of sialic acid in body fluids. There are important implications for the formulation of human milk substitutes.     

Growth of newborn, term infants fed soy formulas for 1 year.

Few studies have measured long-term growth in infants fed soy protein-based formulas. The effect of nucleotide (NT) supplementation of soy protein-based infant formulas on growth is unknown. Growth was therefore evaluated in healthy term infants fed a soy protein-based formula (SOY; n = 73), SOY with added NT (72 mg added NT/L) at human milk (HM) levels (SOYN, n = 73), or mixed feeding (MF, n = 67) in a randomized, masked, parallel 1-year feeding study. The MF group (a nonrandomized reference group) was fed HM exclusively from birth to 2 months of age followed by HM and/or a standard milk-based formula (Similac with Iron with no supplemental NTs) to 1 year of age. Results indicated that growth (weight, length, and head circumference) was normal and comparable among the three groups. All three groups had similar plasma albumin (at 2 months of age) and hemoglobin levels (at 12 months of age). Thus, this study demonstrated similar growth in the first year of life among infants fed MF feeding or soy formula with or without supplemental NTs.     

Plasma amino acid and protein concentrations in infants fed human milk or a whey protein hydrolysate formula during the first month of life

The aim of the study was to compare growth parameters, biochemical indices of protein metabolism and plasma amino acid concentrations in infants fed either human milk ( n = 12) or a whey protein hydrolysate formula ( n = 13) during the first month of life. Growth and gain in skin fold thickness were similar in both groups whereas serum protein concentration was significantly decreased (57.4 ± 3.9 versus 61.2 ± 2.9 g/l) in the infants fed the whey hydrolysate formula. The discrepancies between the plasma amino acid pattern of the whey hydrolysate formula group and that of the human milk group lessened during the first month. Nevertheless, at a mean age of 33 days the plasma threonine concentration remained twice as high and the plasma tyrosine, phenylalanine and proline concentrations were Significantly lower in the whey hydrolysate formula group than in the human milk group. Thus, compared with breast-fed infants, growth and most of the biological indices of protein metabolism were satisfactory in infants fed during the first month of life on a whey protein hydrolysate formula. Nevertheless, the decrease in total plasma protein concentration needs to be confirmed in a larger cohort of infants. In addition, further research is necessary to investigate the possible ways of reducing the hyperthreoninemia and preventing other plasma amino acid disturbances since it would be desirable to obtain plasma amino acid levels similar to those of breast-fed infants.     

Preterm infants fed nutrient‐enriched formula until 6 months show improved growth and development

Background: The purpose of the present study was to determine the effect of feeding nutrient‐enriched preterm formula to preterm infants until 6 months' corrected age (CA) on growth and development in the first 18 months of life. Methods: Very low‐birthweight preterm infants were fed preterm formula until term (40 weeks CA). Infants were then assigned to one of three groups and were fed term formula until 6 months' CA (group 1, n= 29); preterm formula to 3 months' CA and then term formula to 6 months' CA (group 2, n= 30); or preterm formula until 6 months' CA (group 3, n= 31). Anthropometry was performed at term, 3, 6, 9, 12, 15, and at s18 months' CA. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 months' CA. Results: Although body weight, length, head circumference and z score for CA at term in group 3 were significantly lower than those of groups 1 and 2, growth rates of these parameters were significantly higher in group 3 up to 18 months CA', as compared to groups 1 and 2. The mental developmental index and psychomotor developmental index of the Bayley test were not significantly different between the three groups. Conclusions: Very low‐birthweight preterm infants fed nutrient‐enriched preterm formula until 6 months' CA demonstrated significantly improved growth rates for bodyweight, length and head circumference, and comparable mental and psychomotor development throughout the first 18 months of life.     

Comparison of evoked arousability in breast and formula fed infants

Background: Currently, there is no consistent evidence that breast feeding reduces the risk for sudden infant death syndrome (SIDS). Arousal from sleep is believed to be an important survival mechanism that may be impaired in victims of SIDS. Previously it has been shown that arousability is impaired by the major risk factors for SIDS such as prone sleeping and maternal smoking. Aims: To establish whether arousability was altered by method of feeding, and whether breast fed infants would have lower arousal thresholds. Methods: Forty three healthy term infants were studied using daytime polysomnography on three occasions: 2–4 weeks post-term, 2–3 months post-term, and 5–6 months post-term. Multiple measurements of arousal threshold (cm H₂O) in response to nasal air jet stimulation applied alternately to the nares were made in both active sleep (AS) and quiet sleep (QS) while infants slept supine. Arousal thresholds and sleep period lengths were compared between formula fed and breast fed infants at each age. Results: Arousal thresholds were not different between breast fed and formula fed infants in QS. However, in AS breast fed infants were significantly more arousable than formula fed infants at 2–3 months of age. There was no difference between groups of infants when sleep period length was compared at any study. Conclusions: Breast fed infants are more easily aroused from AS at 2–3 months of age than formula fed infants. This age coincides with the peak incidence of SIDS.     

The Centers for Disease Control and Prevention 2000 growth charts and the growth of breastfed infants

AIM: To evaluate the performance of the 2000 Centers for Disease Control and Prevention (CDC) growth charts in comparison with the National Center for Health Statistics/World Health Organization (NCHS/WHO) reference as a tool for assessing growth in healthy breastfed infants. METHODS: Weight and length measurements were obtained from a pooled longitudinal sample of 226 healthy breastfed infants. Weight-for-age (WA), length-for-age (LA) and weight-for-length (WL) z-scores based on the CDC and NCHS/WHO references were computed for each child. Age-specific mean z-scores and proportions below and above specific cut-off points were calculated. RESULTS: Breastfed infants grow more rapidly in the first 2 mo of life and less rapidly from 3 to 12 mo in relation to the CDC WA curves. Similarly, breastfed infants experience greater linear growth than the CDC median until age 4 mo. Thereafter, the mean LA z-score declines until month 9. Apart from a 1-mo difference in the time when linear growth begins to falter, the pattern of growth is remarkably similar when compared with the two references. The growth trajectories indicate that infants in the CDC reference are heavier and shorter than the NCHS/WHO reference population. Combining the two measurements as WL reveals that higher weight overrides lower length in the CDC versus the NCHS population, thus the estimated prevalence of wasting is higher by the CDC reference. CONCLUSION: As was the case when compared with the NCHS/WHO reference, there are notable differences in the growth trajectory of breastfed infants examined against the CDC reference. A reference based on healthy breastfed infants is required if the growth patterns of infants following international feeding recommendations are to be correctly assessed.     

Growth and development of premature infants fed predominantly human milk, predominantly premature infant formula, or a combination of human milk and premature formula

BACKGROUND: In a recent meta-analysis, human milk feeding of low birth-weight (LBW) infants was associated with a 5.2 point improvement in IQ tests. However, in the studies in this meta-analysis, feeding regimens were used (unfortified human milk, term formula) that no longer represent recommended practice. OBJECTIVE: To compare the growth, in-hospital feeding tolerance, morbidity, and development (cognitive, motor, visual, and language) of LBW infants fed different amounts of human milk until term chronologic age (CA) with those of LBW infants fed nutrient-enriched formulas from first enteral feeding. METHODS: The data in this study were collected in a previous randomized controlled trial assessing the benefit of supplementing nutrient-enriched formulas for LBW infants with arachidonic acid and docosahexaenoic acid. Infants (n = 463, birth weight, 750-1,800 g) were enrolled from nurseries located in Chile, the United Kingdom, and the United States. If human milk was fed before hospital discharge, it was fortified (3,050-3,300 kJ/L, 22-24 kcal/oz). As infants were weaned from human milk, they were fed nutrient-enriched formula with or without arachidonic and docosahexaenoic acids (3,300 kJ/L before term, 3,050 kJ/L thereafter) until 12 months CA. Formula fed infants were given nutrient-enriched formula with or without added arachidonic and docosahexaenoic acids (3,300 kJ/L to term, 3,050 kJ/L thereafter) until 12 months CA. For the purposes of this evaluation, infants were categorized into four mutually exclusive feeding groups: 1) predominantly human milk fed until term CA (PHM-T, n = 43); 2) >/= 50% energy from human milk before hospital discharge (>/= 50% HM, n = 98); 3) < 50% of energy from human milk before hospital discharge (< 50% HM, n = 203); or 4) predominantly formula fed until term CA (PFF-T, n = 119). RESULTS: PFF-T infants weighed approximately 500 g more at term CA than did PHM-T infants. This absolute difference persisted until 6 months CA. PFF-T infants were also longer (1.0-1.5 cm) and had larger head circumferences (0.3-1.1 cm) than both PHM-T and >/= 50% HM infants at term CA. There was a positive association between duration of human milk feeding and the Bayley Mental Index at 12 months CA (P = 0.032 full and P = 0.073 reduced, statistical models) after controlling for the confounding variables of home environment and maternal intelligence. Infants with chronic lung disease fed >/= 50% HM until term CA (n = 22) had a mean Bayley Motor Index about 11 points higher at 12 months CA compared with infants PFF-T (n = 24, P = 0.033 full model). CONCLUSION: Our data suggest that, despite a slower early growth rate, human milk fed LBW infants have development at least comparable to that of infants fed nutrient-enriched formula. Exploratory analysis suggests that some subgroups of human milk fed LBW infants may have enhanced development, although this needs to be confirmed in future studies.     

Dietary copper intake in artificially fed infants.

Plasma concentrations of copper and zinc and leucocyte concentrations of zinc were measured in mothers during later pregnancy, at delivery, and 8-10 weeks after birth, and plasma concentrations of copper and zinc were measured in their infants at delivery and 8-10 weeks after birth. The 145 infants were either breast fed or fed one of two milk formulas supplying copper at different concentrations. None of the infants achieved the minimum copper intakes recommended by the World Health Organisation (WHO). At 2 months of age there were no major differences in growth or health detected in infants fed the different copper intakes. Infant birth weight correlated well with the ratio of maternal venous plasma zinc:maternal leucocyte zinc at delivery. Maternal venous plasma copper and zinc concentrations at birth correlated with umbilical venous plasma copper and zinc concentrations. Infants fed the higher copper content formulas had a low mean plasma zinc concentration without a significant increase in the mean plasma copper concentration. The present WHO recommendations regarding minimum copper intakes for infants fed formulas cannot be achieved with currently available formulas and are probably wrong.     

Vitamin K1 and K2 status and faecal flora in breast fed and formula fed 1-month-old infants

Faecal vitamin K₁ (VK₁, phylloquinone) and vitamin K₂ (menaquinone, MK) concentrations were measured in 12 breast fed and 9 formula fed 1-month-old infants. Faecal concentrations of VK₁ and MK-5 to-9 were significantly higher in the formula fed than in the breast fed infants. There was also a tendency for higher total faecal MK (4–10) concentrations in the formula fed [geometric mean (95% confidence intervals); 8995.0 (3872.6, 20893.0) pmol/g of dry faeces] than in the breast fed infants [2937.7 (1285.3, 6714.3),P=0.051]. The numbers of streptococci andEscherichia coli were 100 and 10 times higher, respectively, in the faeces of the formula fed than in those of the breast fed infants. Faecal concentrations of MK-6,-7 and-8, and MK-8 were correlated with the numbers of streptococci andE. coli in the faeces, respectively. Serum VK₁ and MK concentrations were measured in 9 out of 12 breast fed and eight out of nine formula fed infants. The serum VK₁ concentration was much higher in the formula fed infants [average (95% CI); 2.20 (1.48, 2.92) pmol/ml] than in the breast fed ones [0.30 (–0.10, 0.70),P=0.000], but MKs were not detected in the sera of most of the formula fed infants.