Vitamin K1 (phylloquinone) and vitamin K2 (menaquinone) status in newborns during the first week of life

Since 1961 the Committee on Nutrition of the American Academy of Pediatrics has recommended that prophylactic vitamin K be administered parenterally to all newborn infants, although the exact requirement for vitamin K in the newborn infant is unknown. There is little information about the vitamin K1 (phylloquinone, present in green vegetables) and vitamin K2 (menaquinones, synthesized by intestinal flora) status of newborn infants. In this study during the first week of life vitamin K status was assessed by measuring serum concentrations of phylloquinone in 23 mother-infant pairs at the time of birth. Maternal phylloquinone concentration (1.7 +/- 1.0 ng/mL, mean +/- SD) was significantly higher (P less than .02) than cord serum concentration (1.1 +/- 0.6 ng/mL). All infants were then given a standard 1-mg injection of vitamin K1. Ten infants were fed formula (containing 58 ng/mL of vitamin K1) and 13 were exclusively breast-fed. On day 5 of life, serum concentrations of vitamin K1 did not differ between breast-fed (21.0 +/- 12.4 ng/mL) and formula-fed (27.5 +/- 9.7 ng/mL) infants, reflecting the large amounts of parenteral vitamin K1 at birth. During the first week of life, formula-fed infants had much higher fecal concentrations of vitamin K1 (due to large oral intake) and more significant quantities (greater than or equal to 200 pmol/g of dry weight) of fecal menaquinones (reflecting differences in bacterial flora) than did breast-fed infants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vitamin K status of lactating mothers and their infants

Vitamin K deficiency remains a world-wide problem in the newborn. Vitamin K traverses the placenta from mother to infant very poorly and is present only in very low concentrations in human milk. Thus, it is not surprising that the newborn infant has undetectable vitamin K serum levels with abnormal amounts of the coagulation proteins and undercarboxylated prothrombin. Hemorrhagic disease of the newborn, secondary to vitamin K deficiency, remains largely a disease of breastfed infants. Lactating mothers easily achieve the recommended dietary allowance for vitamin K (1 microg kg(-1) d(-1)) and the breast milk concentration is readily increased by increasing maternal vitamin K intake. Breastfed infants do not receive the recommended vitamin K intake via human milk. To prevent vitamin K deficiency in the newborn, intramuscular or oral vitamin K prophylaxis is necessary.     

Vitamin K status of lactating mothers and their infants

Vitamin K deficiency remains a world-wide problem in the newborn. Vitamin K traverses the placenta from mother to infant very poorly and is present only in very low concentrations in human milk. Thus, it is not surprising that the newborn infant has undetectable vitamin K serum levels with abnormal amounts of the coagulation proteins and undercarboxylated prothrombin. Hemorrhagic disease of the newborn, secondary to vitamin K deficiency, remains largely a disease of breastfed infants. Lactating mothers easily achieve the recommended dietary allowance for vitamin K (1 μg kg⁻¹ d⁻¹) and the breast milk concentration is readily increased by increasing maternal vitamin K intake. Breastfed infants do not receive the recommended vitamin K intake via human milk. To prevent vitamin K deficiency in the newborn, intramuscular or oral vitamin K prophylaxis is necessary.     

Plasma total homocysteine increases from day 20 to 40 in breastfed but not formula-fed low-birthweight infants

Homocysteine is an intermediate in the folate cycle and methionine metabolism. This study investigated whether formula-fed infants have different plasma total homocysteine to their breastfed counterparts, and during what period any difference developed. Plasma total homocysteine was determined in 53 formula-fed and 15 breastfed healthy low-birthweight babies (< or = 2500 g) around days 10, 20 and 40. Total homocysteine was also measured in human milk. Mean +/- SD plasma total homocysteine levels (micromol l(-1)) at days 10, 20 and 40 were 6.4 +/- 2.6, 6.7 +/- 2.4 and 9.1 +/- 2.4 (breastfed), and 7.5 +/- 3.2, 7.3 +/- 2.1 and 7.4 +/- 1.6 (formula-fed). Homocysteine of breastfed babies at day 40 was higher than that of breastfed babies at day 20 (p < 0.0001), and that of formula-fed counterparts at day 40 (p = 0.002). Homocysteine correlated negatively with formula (day 10) and breast milk (day 40) volume intakes. Median (range) homocysteine in 12 mature human milk samples was 0.30 (not detectable to 0.7) micromol l(-1). Conclusion: Increasing plasma total homocysteine in breastfed babies to higher levels compared with formula-fed babies may be caused by a gradually developing suboptimal B-vitamin status in lactating women.     

Molybdenum in the premature infant

The molybdenum (Mo) levels in the plasma and urine of 30 premature and 15 full-term infants have been compared with the Mo intakes and urine uric acid excretion (uric acid/creatinine ratio) produced by the Mo enzyme xanthine oxidase. The Mo intakes of full-term infants were 41 +/- 14 nmol/kg/day (mean +/- SEM). In the premature group breast milk supplied significantly less Mo (4.3 +/- 0.4 nmol/kg/day) than infant formulas (101 +/- 31 nmol/kg/day) or premature formula (255 +/- 13 nmol/kg/day). When fed breast milk, the preterm infants displayed similar or higher plasma and urine Mo and urine uric acid levels than formula-fed infants. For the whole preterm group a significant correlation was determined for urine Mo levels and Mo intakes as well as for plasma Mo and uric acid excretion. The bioavailability of breast milk Mo seems to be higher than formula Mo according to the Mo levels and to their statistical link with uric acid excretion which could be proposed as a functional index of Mo status. These parameters displayed similar values in breast milk-fed prematures and control full-term infants. The Mo needs of formula-fed premature newborns remain to be defined using complete balance trials.     

Vitamin K in preterm breastmilk with maternal supplementation

Six healthy lactating mothers who gave birth to preterm infants at a median post conceptional age of 29.5 (range 26-30) weeks were given 2.5 mg phylloquinone (vitamin K1) orally daily for 2 weeks beginning at a median postconceptional age of 31.5 (range 28–32) weeks. Phylloquinone was measured in the breastmilk daily for 14 d. Trough plasma phylloquinone concentrations were also determined on four occasions. Phylloquinone levels in the breastmilk increased from a baseline of 3 ± 2.3ngml^-1 to 22.6 ± 16.3 ng ml^-1 (mean ± SD) after the first dose ( p < 0:05); a gradual increase was noted until phylloquinone levels reached a plateau of 64.2 ± 31.4ng ml^-1 after the sixth daily dose.     

Selenium supply and glutathione peroxidase activity in breastfed Polish infants

Selenium (Se) concentration in human milk in Poland is below 10 ng ml^?1 and the Se intake by breastfed infants is about 6 μg day^?1. Supplementation of lactating mothers with selenium-enriched yeast increases rapidly and significantly the Se concentration and glutathione peroxidase activity in maternal blood components. Se concentration in milk is also significantly elevated. After 1 month the mean Se intakes by breastfed infants were greater than the recommended dietary allowance of 10 μg day^?1 for infants from birth to 6 months of age.     

Oral vitamin A, E and D supplementation of pre-term newborns either breast-fed or formula-fed: a 3-month longitudinal study

BACKGROUND: In contrast to the studies of vitamin A and E status in children, adolescents and adults, information on preterm infants is scarce. In the present investigation we examined the vitamin A, D and E status of pre-term infants at birth, and verified whether, at 1 and 3 months, breast or formula feeding affected the plasma concentration of those vitamins while being supplemented with Uvesterol ADEC. PATIENTS AND METHODS: In this prospective study, 2 groups of consecutively recruited preterm newborns fed either breast milk or formula received 3000 IU of vitamin A, 5 IU of vitamin E and 1000 IU of vitamin D daily. Vitamin A and E were measured by high performance liquid chromatography and spectrophotometry. 25-hydroxyvitamin D, a surrogate marker for vitamin D status, was measured by radioimmunoassay, and retinol binding-protein concentration was measured by immunonephelometry. RESULTS: At birth, formula-fed and breast-milk fed infants had similar plasma concentrations of vitamin A (0.75 +/- 0.20 and 0.64 +/- 0.21 micromol/L, ns), 25-hydroxyvitamin D (34.4 +/- 25.6 and 47.5 +/- 26.7 nmol/L, ns) and vitamin E (9.5 +/- 3.2 and 8.4 +/- 3.3 micromol/L, ns). Vitamins A and E, and retinol binding-protein concentrations steadily increased with time in both groups of infants without attaining, at 3 months, values considered normal in term infants and in young children. At 3 months of age, concentrations of 25-hydroxyvitamin D reached values comparable to those observed in term infants. CONCLUSION: Plasma concentrations of vitamins A and E and of retinol binding-protein steadily increased during the the study without reaching full repletion values. At the conclusion of the study, the type of nutrition did not affect plasma vitamin concentrations.     

Analysis of chromosome aberrations and sister chromatid exchanges in peripheral blood lymphocytes of newborns after vitamin K prophylaxis at birth.

In many countries vitamin K prophylaxis at birth is recommended to prevent bleeding in infants due to vitamin K deficiency. Because the incidence of clinical vitamin K deficiency is very low, such a vitamin K administration should be completely safe. However, an increase in sister chromatid exchanges in lymphocytes of fetal sheep 24 h after injection of vitamin K1 has been reported. Therefore, a study concerning genotoxicity of vitamin K1 in man was conducted. Sister chromatid exchanges and chromosome aberrations were analyzed in peripheral blood lymphocytes of six newborns 24 h after intramuscular administration of 1 mg vitamin K1 and in six control neonates. The mean number of sister chromatid exchanges per metaphase in the vitamin K group was 8.88 +/- 1.22 as compared with 9.05 +/- 1.14 in the control group (NS). The mean number of chromosome aberrations per 100 mitoses was 3.00 +/- 2.61 in the vitamin K group and 2.50 +/- 1.87 in the control group (NS). Vitamin K1 plasma concentrations ranged from 115 to 1150 ng/mL (255 to 2555 x 10(-9) M) in the supplemented group, a 5000-fold rise as compared with the control group (p less than 0.01). We did not find any evidence for genetic toxicity due to the administration of 1 mg vitamin K1 intramuscularly to the newborn child.     

Effects of exclusive formula or breast milk feeding on oxidative stress in healthy preterm infants.

BACKGROUND: Compared to formula, breast milk is considered to have superior antioxidant properties and consequently may reduce the occurrence of a number of diseases of prematurity associated with oxidative stress. AIMS: To test whether the antioxidant properties of breast milk in healthy premature infants are different to those of formula milk by comparing vitamin E levels in milk and determining the excretion of malondialdehyde (MDA) in urine. METHODS: Vitamin E was measured in the breast milk of 20 mothers who had given birth prematurely. Urinary MDA was measured in 10 exclusively breast milk fed and 10 exclusively formula fed healthy preterm infants receiving no vitamin supplements. MDA was measured after derivatisation with 2,4-dinitrophenylhydrazine and consecutive HPLC with UV detection. RESULTS: Urinary MDA concentrations were consistently very low (0.074+/-0.033 microM/mM Cr and 0.078+/-0.026 microM/mM Cr in breast and formula fed infants respectively) and not significantly different between healthy breast milk and formula fed infants. Both breast and formula milk contained satisfactory levels (0.3-3.0 mg/100 ml) of vitamin E. CONCLUSION: Antioxidant properties of both breast milk and formulae are sufficient to prevent significant lipid peroxidation in healthy premature infants.     

Vitamin D metabolism, mineral homeostasis, and bone mineralization in term infants fed human milk, cow milk-based formula, or soy-based formula

The purpose of this study was to evaluate mechanisms of mineral homeostasis and mineralization in term infants with recommended vitamin D intakes. Infants fed human milk (nine), cow milk-based formula (11), or soy-based formula (11) were studied at 2 weeks and at 2, 4, 6, 9, and 12 months of age. While receiving 400 IU of vitamin D, all infants maintained serum vitamin D concentrations higher or equal to normal adult concentrations, and serum 25-hydroxyvitamin D levels were maintained at or above normal adult levels. Serum 1,25-dihydroxyvitamin D concentrations were higher than those of adults in the formula-fed but not in the human milk-fed infants. Serum calcium and phosphorus values were similar in all groups; however, urine phosphorus excretion and urine calcium excretion were adjusted to intakes. Serum parathyroid hormone values were normal in all groups. Bone mineral content significantly increased with age similarly in all groups; however, an apparent plateau occurred at 6 months of age in all groups. Bone width steadily increased with age. Taken as a whole, these data suggest that the vitamin D-sufficient term infant fed human milk, cow milk-based formula, or the soy-based formula studied can regulate mineral metabolism within acceptable physiologic limits to attain similar levels of serum minerals and bone mineral content.     

Selenium and human lactation in Australia: milk and blood selenium levels in lactating women, and selenium intakes of their breast-fed infants

A series of 20 mother-infant pairs were studied in Brisbane, Australia, at 6-12 weeks postpartum. The mean selenium concentration in maternal blood was 101 (SD +/- 19) ng/g and in maternal serum 81(+/- 15) ng/g; serum values appeared low in comparison with those reported for lactating women from Japan and the USA, but similar to those from Finland and from a previous Australian study. Breast milk selenium concentrations (11.9 +/- 3.5 ng/g) were also low by international standards, but not as low as in New Zealand or Scandinavia. There was no correlation between selenium concentrations in milk and blood (or serum). The infants' 24-h breast-milk intakes were 856 +/- 172 g, and their 24-h selenium intakes 10.7 +/- 4.1 micrograms (compared to the Australian RDI of 10 micrograms).     

Vitamin K1 content of maternal milk: influence of the stage of lactation, lipid composition, and vitamin K1 supplements given to the mother

Using a sensitive electrochemical assay for vitamin K1 and standardized techniques for breast-milk collection, we studied the vitamin K1 content of human milk during the first 5 wk of lactation with respect to 1) individual and interindividual differences, 2) the relationship of vitamin K1 to other lipids, and 3) the influence of oral supplements of vitamin K1 on breast milk concentrations. Comparison of fore and hind milk from the mothers revealed higher vitamin K1 concentrations in hindmilks, suggesting that the lipid content influences the vitamin K1 concentration in maternal milk. Samples of maternal milk from nine mothers collected from day 1 to day 36 of lactation showed significantly higher vitamin K1 concentrations in colostral milk than in mature milk. For colostral milk there was a significant correlation of vitamin K1 to cholesterol (r = 0.62) but not to total lipid or phospholipid suggesting a role for cholesterol in the secretion of vitamin K1 into colostral milk. For mature milk correlation coefficients of vitamin K1 with all lipids were low (r = 0.29-0.37) suggesting that at later stages of lactation dietary fluctuations of vitamin K1 may be a more important determinant of the vitamin K1 content of breast milk than the lipid composition. To test the influence of diet, mothers were given oral supplements of vitamin K1.(ABSTRACT TRUNCATED AT 250 WORDS)     

sCD31/sPECAM-1 levels in breast milk and sera of mother-infant pairs in the early postpartum period

Immunomediators seem to have a central role in the immune system of both human milk and newborn infants. CD31/PECAM-1 is an adhesion molecule, member of Ig gene superfamily, mediating cell-cell adhesion in both homophilic and heterophilic ways. Levels of the soluble form of PECAM-1 (sPECAM-1) were evaluated on the 2nd and 5th day postpartum in breast milk and serum paired samples from 20 lactating women as well as in time-matched serum from their single, term, healthy neonates. Concentrations of sPECAM-1 in breast milk (median, range) on both the 2nd (2.05 ng/ml, 0.0-7.2) and 5th day postpartum (0.89 ng/ml, 0.0-3.6) were about 10 and 20 times lower than those (mean +/- SD) in controls (healthy adults) (19.83 +/- 5.17, p<7 x 10(-8)), showing a significant fall from the 2nd to the 5th day postpartum (p<0.0005). Maternal serum sPECAM-1 values (mean +/- SD) were significantly lower on the 2nd day postpartum (14.21 +/- 5.15 ng/ml) than those in controls (p<0.002), but reached control values on the 5th day postpartum after a significant rise (p<0.0075). Neonatal serum sPECAM-1 values with no significant difference between the 2nd (14.4 +/- 4.11 ng/ml) and 5th day of life (14.54 +/- 4.99 ng/ml) were significantly lower than those in controls (p<0.002). Values of sPECAM-1 in milk and sera of lactating mothers and their neonates on the 2nd day postpartum depended on the mode of delivery, being significantly lower after caesarean section (p<0.034, p<0.0075 and p<0.035, respectively). In conclusion, our findings in the early postpartum period demonstrate that: (a) sPECAM-1 is present in human milk in low and decreasing concentrations; (b) the shedding of sPECAM-1 is an established component of the neonatal immune system from birth, though in lower concentrations than in adults, possibly reflecting its immaturity; and (c) the mode of delivery has a significant effect on sPECAM-1 values in milk and sera of lactating mothers and their neonates; the lower values after caesarean section may reveal a deranged endothelial homeostasis.     

A modified vitamin regimen for vitamin B2, A, and E administration in very-low-birth-weight infants

INTRODUCTION: Very-low-birth-weight (VLBW; birth weight, <1,500 g) infants receive preterm infant formulas and parenteral multivitamin preparations that provide more riboflavin (vitamin B2) than does human milk and more than that recommended by the American Society of Clinical Nutrition. VLBW infants who are not breast-fed may have plasma riboflavin concentrations up to 50 times higher than those in cord blood. The authors examined a vitamin regimen designed to reduce daily riboflavin intake, with the hypothesis that this new regimen would result in lower plasma riboflavin concentrations while maintaining lipid-soluble vitamin levels. METHODS: Preterm infants with birth weight < or =1,000 g received either standard preterm infant nutrition providing 0.42 to 0.75 mg riboflavin/kg/day (standard group), or a modified regimen providing 0.19 to 0.35 mg/kg/day (modified group). The modified group parenteral vitamin infusion was premixed in Intralipid. Enteral feedings were selected to meet daily riboflavin administration guidelines. Plasma riboflavin, vitamin A, and vitamin E concentrations were measured weekly by high-performance liquid chromatography. Data were analyzed with the independent t test, chi, and analysis of variance. RESULTS: The 36 infants (17 standard group, 19 modified group) had birth weight and gestational age of 779 +/- 29 g and 25.5 +/- 0.3 weeks (mean +/- SEM) with no differences between groups. Modified group infants received 38% less riboflavin (0.281 +/- 0.009 mg/kg/day), 35% more vitamin A (318.3 +/- 11.4 microg/kg/day), and 14% more vitamin E (3.17 +/- 0.14 mg/kg/day) than standard group infants. Plasma riboflavin rose from baseline in both groups but was 37% lower in the modified group during the first postnatal month (133.3 +/- 9.9 ng/mL). Riboflavin intake and plasma riboflavin concentrations were directly correlated. Plasma vitamin A (0.222 +/- 0.022 microg/mL) and vitamin E (22.26 +/- 1.61 /mL) concentrations were greater in the modified group. CONCLUSIONS: The modified vitamin regimen resulted in reduced riboflavin intake and plasma riboflavin concentration, suggesting plasma riboflavin concentration is partially dose dependent during the first postnatal month in VLBW infants. Modified group plasma vitamin A and vitamin E concentrations were greater during the first month, possibly because the vitamins were premixed with parenteral lipid emulsion. Because of the complexity of this protocol, the authors suggest that a parenteral multivitamin product designed for VLBW infants which uses weight-based dosing should be developed.     

Whey predominant,whey modified infant formula with protein/energy ratio of 1.8 g/100 kcal: adequate and safe for term infants from birth to four months

BACKGROUND: Protein quality of breast milk is superior to that of formula proteins. To ensure that the protein intake is sufficient, starter formulas with conventional protein composition provide a protein/energy ratio of 2.2-2.5 g per 100 kcal to infants, which is much higher than that supplied with breast milk. Several studies have shown that formula-fed infants have higher plasma or serum urea concentrations than breast-fed infants do. We tested if feeding formulas with improved protein quality and a protein content corresponding to the minimum level that is consistent with international recommendations (1.8 g/100 kcal) allows patients to achieve normal growth and plasma urea concentrations. METHODS: Healthy term infants were enrolled into the study and were either breast-fed or randomly assigned to three formula-fed groups. Formula-fed infants received either a standard formula with a protein/energy ratio of 2.2 g/100 kcal, whereas the two other groups received formulas with a protein/energy ratio of 1.8g/100 kcal differing mainly by their source of protein. Subjects received breast milk or these formulas ad libitum as the sole source of energy from birth to four months of age in a controlled blind design (except for the breast-fed group). Anthropometric measurements (body weight and length) were obtained at birth, at 30, 60, 90, and 120 days. Energy and protein intakes were calculated from three-day dietary records. Blood was collected for biochemical measurements at 30, 60, and 120 days. RESULTS: No differences were found between the four feeding groups for weight- and length-gains or for body mass indices (BMI). No differences in energy intakes between the formula-fed groups could be found, whereas protein intakes were less in infants fed the 1.8 g/100 kcal formulas. Plasma urea levels of the infants fed the 1.8 g/100 kcal formulas were closer to those found in the breast-fed infants. CONCLUSION: Improvement of the amino acid profile permits a whey predominant starter formula with 1.8 g protein per 100 kcal to meet the needs of normal term infants during the first four months of life.     

The effect of Ramadan on maternal nutrition and composition of breast milk

BACKGROUND: There are many advantages of breast milk for infants. Many factors can affect the volume and composition of breast milk. One of them is the maternal diet. The objective of this study is to determine the effect of Ramadan fasting on maternal nutrition and breast milk composition. METHODS: A total of 21 breast-feeding mothers aged between 17 and 38 years who fasted during Ramadan month and volunteered to give milk samples were surveyed. The ages of the infants were between 2 and 5 months. The study was performed during Ramadan and 2 weeks after the end of Ramadan. RESULTS: The results showed that during Ramadan, zinc, magnesium and potassium levels in breast milk decreased significantly (P<0.05). The mother's weight increased approximately 1 kg after Ramadan. Changes in body mass index of the mother were not statistically significant. A significant decrease in vitamin A intake was observed after Ramadan (P < 0.05). During Ramadan, energy and most nutrient intakes except protein and vitamins A and C were found below daily recommended dietary allowances necessary for lactating women. CONCLUSIONS: Ramadan fasting had no significant effect on the macronutrient composition of the breast milk and consequently the growth of the infants. There were significant differences in some of the micronutrients such as zinc, magnesium and potassium. The nutritional status of lactating women was affected by Ramadan fasting. All of the nutrient intakes (except vitamins A, E and C) decreased during Ramadan. For these reasons, it would seem prudent to excuse lactating women from fasting during Ramadan.     

Antibacterial characteristics in the feces of breast-fed and formula-fed infants during the first year of life

BACKGROUND: Human milk is known to protect infants from a number of infectious diseases. Much less is known about the bioactivity of milk-derived factors in the intestine. In this study, potentially protective characteristics in the feces of breast-fed and formula-fed infants were compared. METHODS: The feces of 26 breast-fed and 18 formula-fed infants were collected during the first year of life. In each sample, the concentrations of total protein, immunoglobulin A, and sialic acid were measured. In addition, the effect of the fecal samples was measured on the adhesion of enteropathogenic Escherichia coli (EPEC) to Caco-2 cells and on transepithelial electrical resistance (TER) during an infection. RESULTS: In the first month, sialic acid and immunoglobulin A were found in the feces of breast-fed infants in substantially higher concentrations than in the feces of formula fed infants (sialic acid, 1197 +/- 370 microg/ mL versus 31 +/- 19 microg/ mL; immunoglobulin A, 0.11 +/- 7 mg/mL versus 0.3 +/- 1 mg/mL) and thereafter decreased to similar levels in half a year. Adhesion of EPEC to Caco-2 cells was inhibited between 65% and 85% by stools from both groups. The decrease of TER during EPEC infection was unaffected by fecal samples of any origin or age. CONCLUSION: Potentially protective factors are present in higher concentrations in the stools of breast-fed infants than in stools of formula-fed infants. Interestingly, feces from breast-fed and formula-fed infants inhibited bacterial adhesion to a similar level, but neither was able to preserve epithelial barrier function.     

Serial serum 25-hydroxyvitamin D and mineral homeostasis in very premature infants fed preterm human milk

Fourteen very low birthweight infants (mean +/- SD 1,070 +/- 180 g and 29.3 +/- 1.9 weeks gestation) fed their own mother's milk were clinically followed until 3-4 months of age with frequent measurements of serum calcium, phosphorus, magnesium, 25-hydroxyvitamin D (25-OHD), parathyroid hormone, alkaline phosphatase, and albumin, and urine calcium, phosphorus, and magnesium. These infants were matched for birthweight and gestation with 14 infants (1,075 +/- 152 g and 29.0 +/- 1.7 weeks) who had been similarly followed during concomitant studies of infants fed standard formula (Similac 20 cal/oz). Urine phosphorus was markedly lower in the breast milk-fed group from initiation of feedings, and serum phosphorus became significantly lower at and after 6 weeks of age. The fall in serum phosphorus was accompanied by a marked calciuria. Parathyroid hormone was suppressed in the breast milk-fed group, although serum calcium was not elevated and did not differ from formula-fed infants. A high incidence of moderate-severe hypomineralization on radiographs was seen in both breast milk- and formula-fed groups. Six of 14 breast-fed infants required phosphorus supplementation at 8-10 weeks of age because of significant hypophosphatemia, hypercalciuria, and hypomineralization. These infants differed from those not requiring phosphorus supplements by being smaller at birth but not of lower gestation, and having persistently low serum 25-OHD at and after 6 weeks of age.     

Dietary supplements for the lactating mother: influence on the trace element content of milk

Milk production is a complex process where nutritional factors interact with structural hormonal and behavioural influences. In recent years important advances have been made in understanding the role of the nutritional status of lactating women on the outcome of breastfeeding. Many questions remain unanswered about the exact requirement of trace elements for lactating mothers. The effect of dietary zinc, copper and iodine supplements on the milk concentration of these micronutrients was studied. The supplementation trial employed a specific balanced nutritional supplement prepared for the nursing mothers. The study was carried out on women living in Ferrara and its surrounding area. The population under study was healthy Italian mothers, of good socioeconomic status, and their normal infants. In total, 32 women were enrolled in the study and 22 completed it. The infants (9F, 13M) were full-term, healthy singletons and were put to breast within 12 h of birth. All women who finished the study completed a 3 d dietary record. Nutrient analysis revealed the following mean daily dietary trace element intake in the lactating mothers: zinc = 12 mg, copper = 1.4 mg and iodine = 145 microg. The zinc and copper dietary intake was in agreement with the daily intake proposed for nursing Italian mothers, while the daily intake of iodine was below the recommended intake of 200 microg. The breastfeeding mothers were placed in 2 groups, with 7 primiparas and 4 multiparas per group: lactating women eating a traditional Italian diet without vitamin and mineral supplements, and lactating women enrolled in the nutrification programme and given a nutritional supplement to their traditional diet. The supplement (PerMamma Abbott) provided 20mg zinc sulfate, 2mg copper sulfate and 116 microg potassium iodide. These quantities cover about 60-90% of the recommended intake for nursing Italian mothers. Samples of 10 ml of milk were collected at 3, 30, 90d postpartum. Zinc milk concentrations declined significantly over the study period for all lactating subjects, without differences in the rate of decline between the women who started supplementation during lactation and those who did not. Copper did not change during the first month of lactation, then declined at day 90 in supplemented and unsupplemented women, without significant differences between the two groups. An early sharp decline in milk iodine occurred in all lactating subjects, independently of iodine supplementation. After the first month of lactation breast milk iodide levels remained stable in all subjects under study. No significant differences between the two study groups were observed. The lack of correlation between the iodide level in breast milk and maternal dietary intake of iodine is not in agreement with previously published reports. The present results indicate that in healthy, well-nourished lactating Italian women, whose diet is adequate, the levels of zinc, copper and iodine in milk are not influenced by short-term supplementary intakes and that the milk levels of the trace elements studied are maintained over different levels of intake. Further research and examination by longitudinal studies are needed to establish the exact relationship between the amount of iodine furnished to the nursing mother and the iodine content of human milk. The role of compensatory homeostatic mechanisms which act during lactation needs further consideration and closer scrutiny.