Human Milk-derived Fortifier Research Articles

Human milk derived fortifiers are associated with glucose, phosphorus, and calcium derangements.

In 2017, our Level IV NICU switched from providing bovine-derived (BOV-fort) to human milk-derived fortifiers (HM-fort) and donor human milk (DHM) to premature infants born ≤ 30 weeks or ≤1250 g. Following this change, providers anecdotally observed increased hypoglycemia, hypercalcemia, and hyperphosphatemia. This study investigated potential laboratory differences between infants fed Bovine vs. Human milk derived fortifier. Lab measurements from 402 infants (232 BOV-fort, 170 HM-fort) born between 2015 and 2019 were compared between groups. The proportion of infants ever having a blood glucose ≤ 45 mg/dL (p < 0.0001) was higher in the HM-fort group. The proportion of infants ever experiencing a phosphorus > 8.0 mg/dL were higher in the HM-fort group (p < 0.0001). The proportion of infants ever experiencing calcium > 11.4 mg/dL was higher in the HM-Fort group (p = 0.019). Provision of HM-Fort and DHM to extremely premature infants is associated with metabolic derangements.

Human milk-derived versus bovine milk-derived fortifier use in very low birth weight infants: growth and vitamin D status.

Human milk-derived fortifier (HMDF) coupled with human milk feeding in extremely premature infants reduces the adverse outcome risks of early exposure to bovine milk ingredients but may not provide enough nutrients for adequate catch-up growth compared with bovine milk-derived fortifier (BMDF). This study aims to compare HMDF and BMDF effects on growth parameters and serum 25-hydroxy vitamin D (25OHD) levels in preterm very low birth weight (VLBW) infants during the first 8 weeks of life. We present a retrospective chart review of inpatient VLBW infants with birth weight <1,500 g and gestational age <32 completed weeks who received either their mother's milk or donor breast human milk fortified with HMDF or BMDF for the first 8 weeks. Weight, head circumference, length gain, and 25OHD level were calculated at 4 and 8 weeks of age. A total of 139 VLBW infants (91 HMDF + 48 BMDF) received fortified human milk without any supplemental premature formula from birth to 4 weeks of age, of whom 44 (37 HMDF + 7 BMDF) continued until 8 weeks of age. There was no statistically significant difference in the growth parameters between the two groups at 4 and 8 weeks of age. Serum 25OHD level in the HMDF group was significantly higher compared with that in the BMDF group at 4 weeks of age despite receiving lower vitamin D supplementation. Similar gain in growth parameters in HMDF and BMDF groups at 4 and 8 weeks of age was observed, suggesting that HMDF provides adequate nutrients for growth in VLBW infants. A higher 25OHD level in HMDF may suggest better absorption.

Economic and Clinical Impact of Using Human Milk-Derived Fortifier in Very Low Birth Weight Infants.

Background: Implementation of exclusive human milk (EHM) feeding defined as mother's own milk or donor human milk fortified with human milk-derived fortifiers can place an economic burden on institutions. Methods: Retrospective study of very low birth weight (VLBW) infants before and after the implementation of EHM feedings. Neonatal demographics and clinical outcomes including necrotizing enterocolitis, severe retinopathy of prematurity, bronchopulmonary dysplasia, late-onset sepsis, days on parenteral nutrition (PN), and length-of-stay were collected. The net cost to the institution was estimated using published data. Results: Sixty-four infants in the pre-EHM period and 57 infants in the post-EHM period were enrolled. Net product acquisition cost in 2020 and 2021 was $884,823. The EHM feeding guideline led to a reduction in the mean length of stay and mean days of PN use by 6.3 and 6.8 days per infant, respectively. This led to a cost saving of $1,813,444 ($31,815 per infant). No significant difference in incidence of short-term morbidities was observed. Combining the cost avoidance from clinical outcomes, the estimated financial impact over 2 years excluding insurance reimbursement was an estimated $ 913,840 ($16,032 per infant). Conclusion: Implementation of EHM-based feeding in VLBW infants is a cost-effective option for neonatal intensive care units that can result in reduced length of stay and days on PN without adversely impacting short-term morbidities.

Human milk cream alters intestinal microbiome of preterm infants: a prospective cohort study.

In very low birth weight (VLBW) infants, human milk cream added to standard human milk fortification is used to improve growth. This study aimed to evaluate the impact of cream supplement on the intestinal microbiome of VLBW infants. Whole genome shotgun sequencing was performed on stool (n = 57) collected from a cohort of 23 infants weighing 500-1250 grams (control = 12, cream = 11). Both groups received an exclusive human milk diet (mother's own milk, donor human milk, and donor human milk-derived fortifier) with the cream group receiving an additional 2 kcal/oz cream at 100 mL/kg/day of fortified feeds and then 4 kcal/oz if poor growth. While there were no significant differences in alpha diversity, infants receiving cream significantly differed from infants in the control group in beta diversity. Cream group samples had significantly higher prevalence of Proteobacteria and significantly lower Firmicutes compared to control group. Klebsiella species dominated the microbiota of cream-exposed infants, along with bacterial pathways involved in lipid metabolism and metabolism of cofactors and amino acids. Cream supplementation significantly altered composition of the intestinal microbiome of VLBW infants to favor increased prevalence of Proteobacteria and functional gene content associated with these bacteria. We report changes to the intestinal microbiome associated with administration of human milk cream; a novel supplement used to improve growth rates of preterm very low birth weight infants. Since little is known about the impact of cream on intestinal microbiota composition of very low birth weight infants, our study provides valuable insight on the effects of diet on the microbiome of this population. Dietary supplements administered to preterm infants in neonatal intensive care units have the potential to influence the intestinal microbiome composition which may affect overall health status of the infant.

Transient Hypoglycemia and Biochemical Differences in Infants Less Than 1,250 G at Birth Fed Human Milk with Human Milk-Derived Fortifier versus Cow Milk-Derived Fortifier.

Fortification of human milk (HM) with either human milk-derived fortifier (HMDF) or cow milk-derived fortifier (CMDF) is important in preterm infants. The objective is to compare the incidence of hypoglycemia, and biochemical values in infants less than 1,250 g at birth fed HMDF versus CMDF. It is a retrospective cohort study on infants less than 1,250 g at birth who were fed with HMDF or CMDF. Hypoglycemia was defined as blood glucose (BG) level equal to or less than 60 mg/dL within 72 hours of full enteral feeds when off total parenteral nutrition and intravenous fluids. Ninety infants were enrolled (HMDF = 61, CMDF = 29). HMDF group had a higher rate of hypoglycemia (46 vs. 24%; p = 0.048) after achievement of full enteral feeding. The median minimum BG was lower (61 vs. 71; p ≤ 0.01), while blood urea nitrogen (12 vs. 6; p ≤ 0.01) and albumin (3.1 vs. 2.7; p ≤ 0.01) were higher in HMDF group compared with CMDF. At full enteral feedings in infants less than 1,250 g at birth, an HMDF diet may predispose to hypoglycemia needing intervention. Close monitoring of BG levels once off parenteral nutrition is recommended. · Exclusive human milk (EHM) feeding results in better nutritional indices.. · EHM feeding at higher calorie/ounce improves growth.. · Blood glucose needs to be monitored when off TPN during EHM feeding..

Exclusive Human Milk Diet for Extremely Premature Infants: A Novel Fortification Strategy That Enhances the Bioactive Properties of Fresh, Frozen, and Pasteurized Milk Specimens

Background: Human milk (HM) fortification has been recommended for the nutritional optimization of very low-birthweight infants. This study analyzed the bioactive components of HM and evaluated fortification choices that could accentuate or attenuate the concentration of such components, with special reference to human milk-derived fortifier (HMDF) offered to extremely premature infants as an exclusive human milk diet. Materials and Methods: An observational feasibility study analyzed the biochemical and immunochemical characteristics of mothers' own milk (MOM), both fresh and frozen, and pasteurized banked donor human milk (DHM), each supplemented with either HMDF or cow's milk-derived fortifier (CMDF). Gestation-specific specimens were analyzed for macronutrients, pH, total solids, antioxidant activity (AA), α-lactalbumin, lactoferrin, lysozyme, and α- and β-caseins. Data were analyzed for variance applying general linear model and Tukey's test for pairwise comparison. Results: DHM exhibited significantly lower (p < 0.05) lactoferrin and α-lactalbumin concentrations than fresh and frozen MOM. HMDF reinstated lactoferrin and α-lactalbumin and exhibited higher protein, fat, and total solids (p < 0.05) in comparison to unfortified and CMDF-supplemented specimens. HMDF had the highest (p < 0.05) AA, suggesting the potential capability of HMDF to enhance oxidative scavenging. Conclusion: DHM, compared with MOM, has reduced bioactive properties, and CMDF conferred the least additional bioactive components. Reinstatement and further enhancement of bioactivity, which has been attenuated through pasteurization of DHM, is demonstrated through HMDF supplementation. Freshly expressed MOM fortified with HMDF and given early, enterally, and exclusively (3E) appears an optimal nutritional choice for extremely premature infants.

Human Milk-Derived Fortifier as Rescue Therapy in Very Preterm Infants Intolerant to Cow's Milk-Derived Fortifier.

This was a retrospective, descriptive study where human milk-derived fortifier (HMDF) was used to rescue infants intolerant to cow's milk-derived fortifier (CMDF). Rescue therapy was used for newborns with feed intolerance, systemic symptoms, or thrombocytosis. In a total of 412 very preterm infants (gestational age ≤ 32 wk) admitted to NICU during the study period, 14 infants met the rescue protocol inclusion criteria. The mean gestational age of these 14 infants was 29.2 ± 1.2 wk and birth weight was 1161 ± 201g. All the infants who received rescue protocol by changing over to HMDF tolerated feeds well and showed a positive growth trend. Four infants had thrombocytosis, out of which 2 infants had elevated platelet count even with HMDF. Premature infants with intolerance to CMDF were effectively managed using HMDF as a rescue protocol. Infants tolerated HMDF well and showed positive growth trends till the discharge.

Safety of Cow's Milk-Derived Fortifiers used with an All Human Milk Base Diet in Very Low Birthweight Preterm Infants: Part II

Recently we published a meta-analyses of morbidity seen with the use of cow’s milk derived fortifier (CMDF) rather than human milk derived fortifier (HMDF) in very low birthweight (VLBW) infants. Here, we further analyse these data to estimate the annual population risk of CMDF-related major morbidity in the United States and Canada. The outcome used was a mortality/morbidity index which was positive if the infants had one or more of death, necrotising enterocolitis, sepsis retinopathy of prematurity or broncho- pulmonary dysplasia. Using the risk difference (RD) between the CMDF and HMDF groups we estimated, provisionally, that 4150 additional VLBW infants in the United States and Canada each year, or an additional infant approximately every 2 hours, may be expected to develop a positive mortality/morbidity index in relation to being fed CMDF – over and above the number of infants with a positive index if fed HMDF. We provide an in-depth discussion of the limitations of our estimate. This analysis provides preliminary evidence of the magnitude of population risk of major neonatal morbidity with use of CMDF versus HMDF in VLBW infants in current practice.

Exclusive human milk diet reduces incidence of severe intraventricular hemorrhage in extremely low birth weight infants

Compare the incidence of severe (grade III/IV) intraventricular hemorrhage (IVH) and/or periventricular leukomalacia (PVL) between two groups of ELBW infants based on diet until 34 weeks corrected gestational age (CGA): (1) Exclusive human milk (EHM)-mother's own and/or pasteurized donor human milk, human milk-derived fortifier, and oral care with colostrum/human milk vs. (2) non-EHM-bovine formula or mother's own milk with bovine-derived fortifier. Retrospective observational study of two groups of ELBW infants based on diet until 34 weeks CGA. There were n = 306 infants, 127 EHM and 179 non-EHM. Demographics and morbidities were similar except higher antenatal steroids and NEC in EHM group. The rate of severe IVH/PVL was lower in EHM compared to non-EHM group (7 vs. 18%, p < 0.006). EHM diet had an independent neuroprotective effect and was associated with decreased incidence of severe IVH/PVL, supporting the need of EHM in ELBW infants.

Effect of 100% human milk-derived fortifier on growth of premature infants with birth weight of 1000–1500 g

Background: Preterm birth has the highest risk of perinatal morbidity and mortality. Nutrition plays a key role in the growth and development of a preterm infant. Fortification of expressed breast milk is followed to provide an optimal nutrition and a faster catch up growth. The new 100% human milk-derived fortifier (HMDF) can help in providing a safe nutritional option for a premature infant. Objective: The objective of the study was to assess the feed tolerance and impact of a new 100% HMDF on growth outcomes of preterm infants. Materials and Methods: In a single-center study, exclusively human milk-fed preterm infants (1000–1500 g birth weight) were chosen to receive human milk fortified with a new 100% HMDF. The fortifier was initiated when the enteral feed volume reached 100 ml/kg/day and was administered until discharge. The primary outcome of the study was to assess feed tolerance and the secondary endpoints included growth parameters. Results: The cohort study comprised 13 infants with a mean gestational age of 31.64±2.2 weeks and birth weight of 1314.62±110.1 g. During the study period, feed interruptions were nil and none of the infants showed any adverse events of clinical significance. Growth outcomes recorded at the end of the study period showed a mean weight gain of 25.97±7.7 g/day, mean length gain of 0.32±0.23 cm/week, and mean head circumference gain of 0.39±0.20 cm/week. The mean weight growth velocity of the infants was 18.37±5.1 g/kg/day. Conclusion: Preterm infants who received a new 100% HMDF demonstrated feed tolerance and weight gain without any clinically significant record of adverse events. The findings indicate that the new HMDF is a safe option for providing an exclusive human milk-based diet. However, a study with a larger study population may be required to reinforce the findings of this study.

Human milk-derived fortifier versus bovine milk-derived fortifier for prevention of mortality and morbidity in preterm neonates.

Preterm infants who are fed breast milk in comparison to infant formula have decreased morbidity such as necrotizing enterocolitis. Multi-nutrient fortifiers used to increase the nutritional content of the breast milk are commonly derived from bovine milk. Human milk-derived multi-nutrient fortifier is now available, but it is not clear if it improves outcomes in preterm infants fed with breast milk. To determine whether the fortification of breast milk feeds with human milk-derived fortifier in preterm infants reduces mortality, morbidity, and promotes growth and development compared to bovine milk-derived fortifier. We searched the following databases for relevant trials in September 2018. Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 9), electronic journal reference databases including MEDLINE (1980 to 20 September 2018), PREMEDLINE, Embase (1974 to 20 September 2018), CINAHL (1982 to 20 September 2018), biological abstracts in the database BIOSIS and conference abstracts from 'Proceedings First' (from 1992 to 2011). We also included the following clinical trials registries for ongoing or recently completed trials: ClinicalTrials.gov (ClinicalTrials.gov), the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP; www.whoint/ictrp/search/en/) and the ISRCTN Registry (www.isrctn.com/), and abstracts of conferences: proceedings of Pediatric Academic Societies (American Pediatric Society, Society for Pediatric Research and European Society for Paediatric Research) from 1990 in the 'Pediatric Research' journal and 'Abstracts online' (2000 to 2017). We included randomized and quasi-randomized controlled trials that compared preterm infants fed breast milk fortified with human milk-derived fortifier versus those fed with breast milk fortified with bovine milk-derived fortifier. The data were collected using the standard methods of Cochrane Neonatal. Two authors evaluated trial quality of the studies and extracted data. We reported dichotomous data using risk ratios (RRs), risk differences (RDs), number needed to treat (NNT) where applicable, and continuous data using mean differences (MDs). We assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. One randomized trial with 127 infants met the eligibility criteria and had low risk of bias. Human milk-based fortifier did not decrease the risk of necrotizing enterocolitis in exclusively breast milk-fed preterm infants (RR 0.95, 95% CI 0.2 to 4.54; 1 study, 125 infants, low certainty of evidence). Human milk-derived fortifiers did not improve growth, decrease feeding intolerance, late-onset sepsis, or death. There is insufficient evidence evaluating human milk-derived fortifier with bovine milk-derived fortifier in exclusively breast milk-fed preterm infants. Low-certainty evidence from one study suggests that in exclusively breast milk-fed preterm infants human milk-derived fortifiers in comparison with bovine milk-derived fortifier may not change the risk of necrotizing enterocolitis, mortality, feeding intolerance, infection, or improve growth. Well-designed randomized controlled trials are needed to evaluate short-term and long-term outcomes.

Necrotizing Enterocolitis Reduction Using an Exclusive Human-Milk Diet and Probiotic Supplementation in Infants With 1000-1499 Gram Birth Weight.

Necrotizing enterocolitis (NEC) is a major complication confronting clinicians caring for premature infants. This investigation compares clinical outcomes before and after quality improvement-program interventions in a population of premature infants at intermediate risk for NEC. This study is a retrospective single-center chart review of infants admitted with a birth weight of 1000-1499 g, excluding major congenital anomalies, over a 6-year period, beginning with implementation of a donor breast-milk program when mother's own milk was not available. Infants were separated into 2 epochs, before (July 2012-December 2013) and after (April 2014-June 2018) introduction of human milk-derived fortifier (Prolacta) and a daily probiotic (FloraBABY) supplement. Comparing 140 preintervention infants with 265 postintervention infants, NEC was significantly lower in the postintervention group: 5.2% vs 1.1% (P=0.046). Somatic growth was similar in both epochs. Quality-improvement initiatives utilizing an exclusive human-milk diet and daily probiotic supplementation were associated with a decreased incidence of NEC in infants with a birth weight of 1000-1499 g. Implementation of the NEC reduction bundle did not affect infant growth.

The Effects of Fortification and Refrigerated Storage on Bioactive Proteins in Holder-pasteurized Donor Human Milk.

The aim of the study was to assess the total protein, lysozyme, and immunoglobulin A (IgA) content of unfortified and fortified Holder-pasteurized donor human milk (HPDHM) during 96 hours of refrigerated storage. HPDHM was prepared in a hospital feeding room and subjected to treatment with 3 different fortifiers: an acidic, bovine-based (F-ACID), a neutral, bovine-based, and a human milk-derived (F-HUM) fortifier. Unfortified HPDHM served as the control (CONTROL). Samples were stored at 4°C, and every 24 hours, a 1-mL aliquot was removed for analysis. At baseline, there was a significant difference in protein (mean, standard deviation) concentration (g/dL) between control (1.3, 0.1) and all other treatments (F-ACID = 2.0, 0.2; neutral, bovine-derived fortifier = 2.2, 0.1; F-HUM = 2.5, 0.1; P < 0.001). Lysozyme and IgA were significantly lower in the F-ACID group (P < 0.001). Lysozyme and IgA were significantly higher in the F-HUM group (P < 0.001). There was no significant effect of storage time (P > 0.9) for all dependent variables. The type of fortifier has a more significant impact on bioactive components in fortified HPDHM than does storage time. Our findings of lack of negative impact of refrigeration storage time on the protein and bioactive components of donor milk strengthen the recent recommendations to extend storage time to 48 hours.

Human milk-derived fortifier versus bovine milk-derived fortifier for prevention of mortality and morbidity in preterm neonates

Human milk-derived fortifier versus bovine milk-derived fortifier for prevention of mortality and morbidity in preterm neonates

Serum phosphorus levels in premature infants receiving a donor human milk derived fortifier.

An elevated serum phosphorus (P) has been anecdotally described in premature infants receiving human milk fortified with donor human milk-derived fortifier (HMDF). No studies have prospectively investigated serum P in premature infants receiving this fortification strategy. In this single center prospective observational cohort study, extremely premature infants ≤1250 grams (g) birth weight (BW) were fed an exclusive human milk-based diet receiving HMDF and serum P levels were obtained. We evaluated 93 infants with a mean gestational age of 27.5 ± 2.0 weeks (Mean ± SD) and BW of 904 ± 178 g. Seventeen infants (18.3%) had at least one high serum P level with a mean serum P of 9.2 ± 1.1 mg/dL occurring at 19 ± 11 days of life. For all infants, the highest serum P was inversely correlated to the day of life of the infant (p < 0.001, R2 = 0.175) and positively correlated with energy density of HMDF (p = 0.035). Serum P was not significantly related to gender, BW, gestational age, or days to full feeds. We conclude that the incidence of hyperphosphatemia was mild and transient in this population. The risk decreased with infant age and was unrelated to gender, BW, or ethnicity.

Effectiveness of Human Milk-Based Fortifiers for Preventing Necrotizing Enterocolitis in Preterm Infants: Case Not Proven

Breastfeeding MedicineVol. 8, No. 4 Letters to the EditorEffectiveness of Human Milk-Based Fortifiers for Preventing Necrotizing Enterocolitis in Preterm Infants: Case Not ProvenNicholas D. Embleton, Caroline King, Chris Jarvis, Helen Mactier, Freya Pearson, and Gopi MenonNicholas D. EmbletonSearch for more papers by this author, Caroline KingSearch for more papers by this author, Chris JarvisSearch for more papers by this author, Helen MactierSearch for more papers by this author, Freya PearsonSearch for more papers by this author, and Gopi MenonSearch for more papers by this authorPublished Online:25 Jul 2013https://doi.org/10.1089/bfm.2013.0049AboutSectionsView articleView Full TextPDF/EPUB ToolsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View article"Effectiveness of Human Milk-Based Fortifiers for Preventing Necrotizing Enterocolitis in Preterm Infants: Case Not Proven." , 8(4), p. 421FiguresReferencesRelatedDetailsCited ByOptimising growth in very preterm infants: reviewing the evidence28 February 2022 | Archives of Disease in Childhood - Fetal and Neonatal Edition, Vol. 40EFFECT OF 100% HUMAN MILK-DERIVED FORTIFIER ON GROWTH OF PREMATURE INFANTS WITH BIRTH WEIGHT OF 1000–1500 G25 January 2020 | Indian Journal of Child Health, Vol. 07, No. 01Fortification of Human Milk for Preterm Infants: Update and Recommendations of the European Milk Bank Association (EMBA) Working Group on Human Milk Fortification22 March 2019 | Frontiers in Pediatrics, Vol. 7Individualized Fortification Influences the Osmolality of Human Milk31 October 2018 | Frontiers in Pediatrics, Vol. 6Donor Human Milk and Fortifier Use in United States Level 2, 3, and 4 Neonatal Care HospitalsJournal of Pediatric Gastroenterology & Nutrition, Vol. 66, No. 4Human Milk—Treatment and Quality of Banked Human MilkClinics in Perinatology, Vol. 44, No. 1Donor Human Milk: No Longer A Place For Formula in the Neonatal Intensive Care Unit?11 October 2014 | Current Pediatrics Reports, Vol. 2, No. 4Fortification of Human Milk in Very Low Birth Weight Infants (VLBW <1500 g Birth Weight)Clinics in Perinatology, Vol. 41, No. 2A Mixed-Methods Observational Study of Human Milk Sharing Communities on Facebook11 April 2014 | Breastfeeding Medicine, Vol. 9, No. 3Research-Based Insights into Increasing the Global Supply and Affordability of Donor Milk11 April 2014 | Breastfeeding Medicine, Vol. 9, No. 3 Volume 8Issue 4Aug 2013 InformationCopyright 2013, Mary Ann Liebert, Inc.To cite this article:Nicholas D. Embleton, Caroline King, Chris Jarvis, Helen Mactier, Freya Pearson, and Gopi Menon.Effectiveness of Human Milk-Based Fortifiers for Preventing Necrotizing Enterocolitis in Preterm Infants: Case Not Proven.Breastfeeding Medicine.Aug 2013.421-421.http://doi.org/10.1089/bfm.2013.0049Published in Volume: 8 Issue 4: July 25, 2013Online Ahead of Print:June 7, 2013PDF download

Human Milk Banking–Facts and Issues to Resolve

The number of human milk banks is increasing worldwide. Although the beneficial effects of feeding premature infants with their mother’s milk are well documented, less is known about the effects of feeding these infants with pasteurized donor milk. We propose a randomized trial comparing the effects of a 100% human milk-based diet (human milk supplemented with a human milk-derived fortifier) and a diet (partially) based on bovine milk. In theory, human milk has a beneficial effect on various aspects of human physiology, most of which become apparent after infancy. We therefore propose an extensive follow-up program that takes this aspect into consideration. Other issues concerning the practice of human milk banks need to be addressed as well as optimization of the feeding strategies for preterm infants.

Mineral balance studies in very low birth weight infants fed human milk

Mineral homeostasis often is disrupted in the very low birth weight (VLBW) infant fed either human milk or commercial formula that contains insufficient quantities of available calcium (Ca) and phosphorus (P). Alterations in mineral homeostasis include abnormal patterns of serum (Ca and P concentrations and alkaline phosphatase activity) and urine (Ca and P) biochemical markers, low net Ca and P retentions in comparison with intrauterine estimates of mineral accretion, and decreased bone mineral content. A two-phase study was conducted in our laboratory to test for these alterations in mineral homeostasis. In phase 1, VLBW infants fed a preparation of fortified human milk (either human milk-derived fortifier I or II or cow milk-derived fortifier) or cow milk-based formula specially designed for VLBW infants were evaluated during their hospitalization. In phase 2, after hospitalization, these infants were evaluated during the first 6 months of life when fed either their mother's milk or routine formula exclusively. The bioavailability of Ca and P from the tested preparations varied widely. Although the fortification of human milk resulted in both an improved biochemical pattern and net retention of Ca and P, optimal intrauterine mineral accretion was not achieved in any group tested. Longitudinal assessments of bone mineralization, by single photon absorptiometry, demonstrated that human milk-fed former VLBW infants had reduced bone mineral content. These investigations suggest that former VLBW infants fed human milk exclusively may be at risk for Ca and P deficiencies.