Intestinal absorption of mixed micellar phylloquinone (vitamin K1) is unreliable in infants with conjugated hyperbilirubinaemia: implications for oral prophylaxis of vitamin K deficiency bleeding

Lipid Nanoparticles: An Effective Tool to Improve the Bioavailability of Nutraceuticals

Nano-range bioactive colloidal carrier systems are envisaged to overcome the challenges associated with treatments of numerous diseases. Lipid nanoparticles (LNPs), one of the extensively investigated drug delivery systems, not only improve pharmacokinetic parameters, transportation, and chemical stability of encapsulated compounds but also provide efficient targeting and reduce the risk of toxicity. Over the last decades, nature-derived polyphenols, vitamins, antioxidants, dietary supplements, and herbs have received more attention due to their remarkable biological and pharmacological health and medical benefits. However, their poor aqueous solubility, compromised stability, insufficient absorption, and accelerated elimination impede research in the nutraceutical sector. Owing to the possibilities offered by various LNPs, their ability to accommodate both hydrophilic and hydrophobic molecules and the availability of various preparation methods suitable for sensitive molecules, loading natural fragile molecules into LNPs offers a promising solution. The primary objective of this work is to explore the synergy between nature and nanotechnology, encompassing a wide range of research aimed at encapsulating natural therapeutic molecules within LNPs.

Take the Shot: A Review of Vitamin K Deficiency

Vitamin K is essential for the process of coagulation. In its absence, severe and sometimes fatal bleeding events can occur, especially in newborns. Vitamin K prophylaxis at birth has been shown to prevent morbidity and mortality associated with vitamin K deficiency bleeding (VKDB) and is recommended by multiple organizations including the American Academy of Pediatrics and the World Health Organization. Pediatricians should feel comfortable explaining the risks and benefits of vitamin K prophylaxis to families and should be equipped to recognize signs of VKDB, especially given increasing rates of parental refusal. This article aims to improve understanding of VKDB, including prevention, early recognition, and treatment. [Pediatr Ann. 2023;52(2):e42-e45.].

Belgian Consensus Recommendations to Prevent Vitamin K Deficiency Bleeding in the Term and Preterm Infant

Neonatal vitamin K prophylaxis is essential to prevent vitamin K deficiency bleeding (VKDB) with a clear benefit compared to placebo. Various routes (intramuscular (IM), oral, intravenous (IV)) and dosing regimens were explored. A literature review was conducted to compare vitamin K regimens on VKDB incidence. Simultaneously, information on practices was collected from Belgian pediatric and neonatal departments. Based on the review and these practices, a consensus was developed and voted on by all co-authors and heads of pediatric departments. Today, practices vary. In line with literature, the advised prophylactic regimen is 1 or 2 mg IM vitamin K once at birth. In the case of parental refusal, healthcare providers should inform parents of the slightly inferior alternative (2 mg oral vitamin K at birth, followed by 1 or 2 mg oral weekly for 3 months when breastfed). We recommend 1 mg IM in preterm <32 weeks, and the same alternative in the case of parental refusal. When IM is perceived impossible in preterm <32 weeks, 0.5 mg IV once is recommended, with a single additional IM 1 mg dose when IV lipids are discontinued. This recommendation is a step towards harmonizing vitamin K prophylaxis in all newborns.

Trends of INR and Fecal Excretion of Vitamin K During Cholestasis Reversal: Implications in the Treatment of Neonates With Intestinal Failure-Associated Liver Disease

BACKGROUND

Vitamin K is a fat-soluble compound that plays important roles in coagulation. In children with intestinal failure-associated liver disease (IFALD), the disrupted enterohepatic circulation can lead to intestinal loss of vitamin K. Fish oil-based lipid emulsion (FOLE) has proven effective in treating IFALD. As biliary excretion is restored during cholestasis reversal, the accelerated vitamin K loss can pose a risk for deficiency.

METHODS

Ten neonates with IFALD and receiving FOLE monotherapy were prospectively enrolled in the study from 2016 to 2018. In addition to weekly measurements of international normalized ratio (INR) and direct bilirubin (DB), ostomy output was collected for determination of fecal concentrations of phylloquinone (PK). Trends of DB, INR, and fecal PK concentrations were summarized with locally estimated scatterplot smoothing.

RESULTS

The median time (interquartile range) from FOLE initiation to cholestasis reversal was 59 (19-78) days. During cholestasis reversal, INR remained relatively unchanged, whereas the mean (95% confidence interval) daily fecal excretion of PK increased from 25.1 (5.0-158.5) ng at the time of FOLE initiation to 158.5 (31.6-1000.0) ng at complete reversal. Examination of individual trends in fecal PK excretion and INR revealed little correlation between the 2 measurements (r = -0.10; P = 0.50).

CONCLUSION

Children with IFALD are at risk for vitamin K deficiency during cholestasis reversal. Close monitoring and quantified supplementation of vitamin K may be warranted during this period. However, this should not be guided by INR alone, as it is a poor indicator of vitamin K status.

Thrombin Generation in Preterm Newborns With Intestinal Failure-Associated Liver Disease

Background and Aim: Intestinal failure-associated liver disease (IFALD) affects one-fifth of neonates receiving parenteral nutrition (PN) for more than 2 weeks. We aimed to define the effect of IFALD on hemostasis of preterm infants. Methods: This is an ancillary analysis of a prospective study aimed at defining coagulation in preterm infants. We included neonates exposed to PN (at least 14 days), in full-enteral feeding. We compared thrombin generation in the presence of thrombomodulin, defined as endogenous thrombin potential-ETP, PT, aPTT between infants with IFALD vs. those without (controls), at birth, and after 30 days. IFALD was defined as conjugated bilirubin ≥1 mg/dl. Results: We enrolled 92 preterm infants (32 IFALD; 60 controls). Cholestatic patients had a lower birthweight, longer exposure to PN, and longer hospitalization. Infants with IFALD showed longer median PT (12.8-vs.-12 sec; p = 0.02) and aPTT (39.2-vs.-36.5 sec; p = 0.04) than controls, with no difference in ETP. Conclusions: Despite prolonged PTs and aPTTs infants with IFALD had similar ETP than those without.

Influence of PEGylation of Vitamin-K-Loaded Mixed Micelles on the Uptake by and Transport through Caco-2 Cells

The aim of the study is to investigate the uptake by and transport through Caco-2 cells of two mixed micelle formulations (based on egg phosphatidylcholine and glycocholic acid) of vitamin K, i.e., with and without DSPE-PEG2000. The uptake of vitamin K and fluorescently labeled mixed micelles with and without PEG coating showed similar kinetics and their uptake ratio remained constant over time. Together with the fact that an inhibitor of scavenger receptor B1 (BLT-1) decreased cellular uptake of vitamin K by ∼80% compared to the uptake in the absence of this inhibitor, we conclude that both types of micelles loaded with vitamin K can be taken up intactly by Caco-2 cells via this scavenger receptor. The amount of vitamin K in chylomicrons fraction from Caco-2 cell monolayers further indicates that mixed micelles (with or without PEGylation) are likely packed into chylomicrons after internalization by Caco-2 cells. Uptake of vitamin K from PEGylated mixed micelles increased four- to five-fold at simulated gastrointestinal conditions. In conclusion, PEGylated mixed micelles are stable upon exposure to simulated gastric conditions, and as a result, they do show overall a higher cellular uptake efficiency of vitamin K as compared to mixed micelles without PEG coating.

Coagulopathy in Zellweger spectrum disorders: a role for vitamin K

INTRODUCTION

Zellweger spectrum disorders (ZSDs) are caused by an impairment of peroxisome biogenesis, resulting in multiple metabolic abnormalities. This leads to a range of symptoms, including hepatic dysfunction and coagulopathy. This study evaluated the incidence and severity of coagulopathy and the effect of vitamin K supplementation orally and IV in ZSD.

METHODS

Data were retrospectively retrieved from the medical records of 30 ZSD patients to study coagulopathy and the effect of vitamin K orally on proteins induced by vitamin K absence (PIVKA-II) levels. Five patients from the cohort with a prolonged prothrombin time, low factor VII, and elevated PIVKA-II levels received 10 mg of vitamin K IV. Laboratory results, including thrombin generation, at baseline and 72 h after vitamin K administration were examined.

RESULTS

In the retrospective cohort, four patients (13.3%) experienced intracranial bleedings and 14 (46.7%) reported minor bleeding. No thrombotic events occurred. PIVKA-II levels decreased 38% after start of vitamin K therapy orally. In the five patients with a coagulopathy, despite treatment with oral administration of vitamin K, vitamin K IV caused an additional decrease (23%) of PIVKA-II levels and increased thrombin generation.

CONCLUSION

Bleeding complications frequently occur in ZSD patients due to liver disease and vitamin K deficiency. Vitamin K deficiency is partly corrected by vitamin K supplementation orally, and vitamin K administered IV additionally improves vitamin K status, as shown by further decrease of PIVKA-II and improved thrombin generation.

Intraventricular Hemorrhage Due to Coagulopathy After Vitamin K Administration in a Preterm Infant With Maternal Crohn Disease

Intraventricular hemorrhage (IVH) is a devastating morbidity in preterm infants and can result in poor neurodevelopmental outcomes. Intraventricular hemorrhage usually occurs within 72 hours after birth; post-acute-phase IVH (>1 week after birth) is uncommon. Development of the hemostatic system in fetuses and neonates is an age-dependent evolving process, and the neonatal hemostatic system is characterized by low levels of vitamin K-dependent factors, with further reduction caused by prematurity. Importantly, a severe coagulation deficiency can be a major contributing factor of IVH. Active maternal Crohn disease (CD) during pregnancy causes malnutrition via enteral malabsorption; this may include vitamin K deficiency, resulting in fetal vitamin K deficiency. We herein describe a preterm infant who was born to a mother with CD and developed post-acute-phase IVH due to coagulopathy despite vitamin K administration.

Nutritional Needs and Support for Children with Chronic Liver Disease

Malnutrition has become a dangerously common problem in children with chronic liver disease, negatively impacting neurocognitive development and growth. Furthermore, many children with chronic liver disease will eventually require liver transplantation. Thus, this association between malnourishment and chronic liver disease in children becomes increasingly alarming as malnutrition is a predictor of poorer outcomes in liver transplantation and is often associated with increased morbidity and mortality. Malnutrition requires aggressive and appropriate management to correct nutritional deficiencies. A comprehensive review of the literature has found that infants with chronic liver disease (CLD) are particularly susceptible to malnutrition given their low reserves. Children with CLD would benefit from early intervention by a multi-disciplinary team, to try to achieve nutritional rehabilitation as well as to optimize outcomes for liver transplant. This review explains the multifactorial nature of malnutrition in children with chronic liver disease, defines the nutritional needs of these children, and discusses ways to optimize their nutritional.

Prevention of Vitamin K Deficiency Bleeding in Newborn Infants: A Position Paper by the ESPGHAN Committee on Nutrition

Vitamin K deficiency bleeding (VKDB) due to physiologically low vitamin K plasma concentrations is a serious risk for newborn and young infants and can be largely prevented by adequate vitamin K supplementation. The aim of this position paper is to define the condition, describe the prevalence, discuss current prophylaxis practices and outcomes, and to provide recommendations for the prevention of VKDB in healthy term newborns and infants. All newborn infants should receive vitamin K prophylaxis and the date, dose, and mode of administration should be documented. Parental refusal of vitamin K prophylaxis after adequate information is provided should be recorded especially because of the risk of late VKDB. Healthy newborn infants should either receive 1 mg of vitamin K1 by intramuscular injection at birth; or 3 × 2 mg vitamin K1 orally at birth, at 4 to 6 days and at 4 to 6 weeks; or 2 mg vitamin K1 orally at birth, and a weekly dose of 1 mg orally for 3 months. Intramuscular application is the preferred route for efficiency and reliability of administration. The success of an oral policy depends on compliance with the protocol and this may vary between populations and healthcare settings. If the infant vomits or regurgitates the formulation within 1 hour of administration, repeating the oral dose may be appropriate. The oral route is not appropriate for preterm infants and for newborns who have cholestasis or impaired intestinal absorption or are too unwell to take oral vitamin K1, or those whose mothers have taken medications that interfere with vitamin K metabolism. Parents who receive prenatal education about the importance of vitamin K prophylaxis may be more likely to comply with local procedures.

Intracranial haemorrhage is linked to late onset vitamin K deficiency in infants aged 2-24 weeks

AIM

Late vitamin K deficiency bleeding (VKDB) can be serious and manifest as early onset intracranial haemorrhage (ICH). This study aimed to determine the frequency of ICH in relation to vitamin K deficiency and the outcome in infants aged two to 24 weeks.

METHOD

A hospital-based study was conducted in two main tertiary hospitals in Cairo, Egypt, from May 2011 to May 2012 with 40 patients with ICH and 50 age-matched controls without ICH.

RESULTS

Forty patients with ICH were recruited, 19 were excluded for clinical reasons and the remaining 21 had a significantly low vitamin K level. Exclusive breast feeding (81% of patients), diarrhoea lasting more than 1 week (38.1%) and antibiotic consumption within a week before the development of ICH (57.1%) were more common in the patients than in the control group (p value>0.05, <0.01 and <0.01, respectively).

CONCLUSION

A high frequency of ICH due to late VKDB was reported in Egyptian infants aged two to 24 weeks, with poorer outcomes than international studies. A national survey is required to evaluate the timing and protective value of a second booster vitamin K dose to reduce ICH, especially in high-risk patients in this age group.

Late haemorrhagic disease of the newborn

BACKGROUND

Late haemorrhagic disease of the newborn (HDN) can occur owing to a lack of vitamin K prophylaxis, as a manifestation of an underlying disorder or idiopatically from the 8th day to 12 weeks after birth.

METHODS

Eight infants admitted to Kocaeli University Hospital with nine episodes of late HDN between January 2002 and April 2005 were evaluated retrospectively from hospital records.

RESULTS

The median age at presentation was 46 (26-111) days. All the infants were born at full-term to healthy mothers and were exclusively breast-fed. All had an uneventful perinatal history, except one who had meconium aspiration. Four patients had received no vitamin K prophylaxis and another three had uncertain histories. At presentation, six had intracranial bleeding and the remainder had bleeding either from the venepuncture site or the gastro-intestinal tract. The presenting signs and symptoms were irritability, vomiting, bulging or full fontanelle, convulsions and diminished or absent neonatal reflexes. Galactosaemia was detected in a 2-month-old infant with prolonged jaundice. There was no surgery-related mortality or complications but one survived for only 2 days on ventilatory support following surgery. Only one of the six survivors had severe neurological sequelae.

CONCLUSIONS

Late HDN frequently presents with intracranial haemorrhage, leading to high morbidity and mortality. HDN can be the manifestation of an underlying metabolic disorder. Vitamin K prophylaxis of the newborn should be routine in developing countries.

VKORC1-dependent pharmacokinetics of intravenous and oral phylloquinone (vitamin K1) mixed micelles formulation

Objective

The pharmacokinetics of phylloquinone (vitamin K1) were evaluated in healthy human adult volunteers (15 male and 15 female) following oral and intravenous administration of a mixed micelles formulation (Konakion® MM 2 mg) in an open label study design. The subjects were allocated to one of three genotype-specific groups (n = 10 in each group) in terms of VKORC1 promoter polymorphism c.-1639 G > A to explore the relationship between genotype and pharmacokinetic parameters.

Methods

Blood samples were collected for up to 24 h after administration. Phylloquinone serum levels were determined by reversed phase HPLC with fluorometric detection after post-column zinc reduction. Pharmacokinetic evaluation was performed using non-compartmental analysis.

Results

Pharmacokinetic analysis of serum phylloquinone concentration versus time profiles revealed significant differences in the main pharmacokinetic parameters between groups. Upon oral administration, VKORC1 AG carriers showed 41 % higher mean bioavailability (p = 0.01) compared with homozygous AA individuals. Furthermore, AG subjects exhibited 30 % (p = 0.042) and 36 % (p = 0.021) higher mean AUC compared with GG and AA respectively. Terminal half-life was 32 % and 27 % longer for AG carriers in comparison to GG (p = 0.004) and AA (p = 0.015) genotypes respectively.

Conclusion

Pharmacokinetic differences indicated significant inter-individual variance of vitamin K fate in the human body. The influence of the VKORC1 promoter polymorphism c.-1639 G > A on the pharmacokinetic properties of phylloquinone could be demonstrated in humans. To gain deeper insight in other potential genetic determinants of systemic vitamin K exposure, further correlation of the phenotype–genotype relationship of different players in vitamin K turnover has to be gained.

Intracranial hemorrhages and late hemorrhagic disease associated cholestatic liver disease

Deficiency of vitamin K predisposes to early, classic or late hemorrhagic disease of the newborn (HDN); of which late HDN may be associated with serious and life-threatening intracranial hemorrhage. Late HDN is characterized intracranial bleeding in infants aged 1 week to 6 months due to severe vitamin K deficiency. Late HDN is still an important cause of mortality and morbidity in developing countries where vitamin K prophylaxis is not routinely practiced. Children with cholestatic liver disease are at risk for developing secondary vitamin K deficiency because of fat malabsorbtion and inadequate dietary intake. In this study, we described 11 infants with cholestatic liver disease with different etiologies exhibiting intracranial hemorrhage (ICH). Six patients underwent surgical evacuation of ICH, following the administration of vitamin K and/or fresh frozen plasma. The possibility of cholestatic liver disease should be considered in the treatment of ICH due to vitamin K deficiency.

Mechanisms underlying the biphasic effect of vitamin K1 (phylloquinone) on arterial blood pressure

Phylloquinone (vitamin K1, VK1) is widely used therapeutically and intravenous administration of this quinone can induce hypotension. We aimed to investigate the mechanisms underlying the effects induced by VK1 on arterial blood pressure. With this purpose a catheter was inserted into the abdominal aorta of male Wistar rats for blood pressure and heart rate recording. Bolus intravenous injection of VK1 (0.5–20 mgkg−1) produced a transient increase in blood pressure followed by a fall. Both the pressor and depressor response induced by VK1 were dose-dependent. On the other hand, intravenous injection of VK1 did not alter heart rate. The nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (L-NAME, 10 and 20 mgkg−1) reduced both the increase and decrease in blood pressure induced by VK1 (5 mgkg−1). On the other hand, indometacin (10 mgkg−1), a non-selective cyclooxygenase inhibitor, did not alter the increase in mean arterial pressure (MAP) induced by VK1. However, VK1-induced fall in MAP was significantly attenuated by indometacin. We concluded that VK1 induces a dose-dependent effect on blood pressure that consists of an acute increase followed by a more sustained decrease in MAP. The hypotension induced by VK1 involves the activation of the nitric oxide (NO) pathway and the release of vasodilator prostanoid(s).

Optimizing nutritional management in children with chronic liver disease

Malnutrition is common in infants and children with chronic liver disease (CLD) and may easily be underestimated by clinical appearance alone. The cause of malnutrition in CLD is multifactorial, although insufficient dietary intake is probably the most important factor and is correctable. Fat malabsorption occurs in cholestatic disorders, and one must also consider any accompanying fat-soluble vitamin and essential fatty acid deficiencies. The clinician should proactively evaluate, treat, and re-evaluate response to treatment of nutritional deficiencies. Because a better nutritional state is associated with better survival before and after liver transplantation, aggressive nutritional management is an important part of the care of these children.

Prevalence of subclinical vitamin K deficiency in cholestatic liver disease

BACKGROUND AND OBJECTIVE

Prothrombin time (PT), a surrogate marker of vitamin K deficiency, may underestimate the prevalence of vitamin K deficiency in cholestatic liver disease. This study investigated the frequency of vitamin K deficiency in children and adults with cholestatic liver disease by determining plasma protein induced in vitamin K absence II (PIVKA-II), and assessed the relation between plasma PIVKA-II levels and markers of cholestasis, measured PT, international normalized ratio (INR), serum undercarboxylated osteocalcin (ucOC), serum vitamins A and E, and serum 25-hydroxyvitamin D levels.

PATIENTS AND METHODS

Blood was collected from patients with cholestatic liver disease for liver biochemistries, PT, INR, bile acids, 25-hydroxyvitamin D, vitamin A, vitamin E, ucOC, and PIVKA-II.

RESULTS

Thirty-one patients were enrolled (age range 0.5-54 years, median age 5.7 years, 17 females). Nine patients (29%) had increased INRs, whereas 21 (68%) had elevated plasma PIVKA-II levels. All patients with increased INRs had increased plasma PIVKA-II. Fifteen of 21 patients with increased plasma PIVKA-II were receiving supplemental vitamin K therapy (range 7.8-700 mug/kg/day). Plasma PIVKA-II levels were positively correlated with serum conjugated bilirubin, bile acids, aspartate aminotransferase, alanine aminotransferase, PT, INR, and serum ucOC (P <or= 0.02) and negatively correlated with serum 25-hydroxyvitamin D levels (P = 0.01). Twenty-two patients (71%) had vitamin D deficiency, 9 patients (29%) had vitamin A deficiency, and 2 patients (6%) had vitamin E deficiency.

CONCLUSIONS

Despite vitamin K supplementation, elevation of plasma PIVKA-II suggesting ongoing vitamin K deficiency is common in cholestatic liver disease. Better strategies for vitamin K supplementation and dosing guidelines are needed.

Vitamin K, an update for the paediatrician

INTRODUCTION

This review summarizes current knowledge on vitamin K for the paediatrician. Vitamin K is a fat-soluble vitamin, present in plants as phylloquinone and produced by bacteria as menaquinone. It is acting as a co-factor for gamma-glutamyl carboxylase. This enzyme is responsible for post-translational modification of some glutamate side chains to gamma-carboxyglutamate. The majority of gamma-carboxylated proteins function in blood coagulation; others play a role in calcium homeostasis.

DATA

Newborn babies are at particular risk of vitamin K deficiency, as placental transfer is limited and human milk is a poor source. Vitamin K prophylaxis at birth effectively prevents vitamin K deficiency bleeding (VKDB), formerly known as "haemorrhagic disease of the newborn". Recent epidemiological studies provide data on the effectiveness of different administration routes and dosing schemes. Infants of mothers taking drugs that inhibit vitamin K are at risk of early VKDB and should receive 1 mg intramuscular (i.m.) as soon as possible after birth. Classic VKDB is prevented by intramuscular as well as by oral administration of 1 mg vitamin K. In exclusively breast-fed infants, single i.m. administration at birth is also effectively preventing (rare) late VKDB but single oral administration is not. If given orally, prophylaxis should be continued by either weekly administration of 1 mg till 12 weeks or repeating 2 mg at weeks 1 and 4. Daily administration of 25 microg offers insufficient protection. The only infants not fully protected in this way are those with yet unrecognised liver disease.

CONCLUSIONS

Further work is needed before firm recommendations can be made regarding dose in preterm infants and in patients with fat malabsorption/cholestasis or regarding the role of vitamin K in the prevention of osteoporosis.

Vitamin K deficiency bleeding (VKDB) in early infancy

Vitamin K deficiency bleeding (VKDB) is a rare and potentially life-threatening bleeding disorder of early infancy. Vitamin K stores are low at birth; thereafter breast-fed infants are at risk because of low concentrations in human milk. Classical VKDB occurs in the first week of life, is related to delayed or inadequate feeding and is readily prevented by small doses of vitamin K at birth. Late VKDB peaks at 3-8 weeks, typically presents with intracranial haemorrhage often due to undiagnosed cholestasis with resultant malabsorption of vitamin K. Diagnosis can be difficult but PIVKA-II measurements can provide confirmation even several days post-treatment. Without vitamin K prophylaxis, the incidence of late VKDB in Europe is 4-7 cases per 10(5) births; it is higher in SE Asia where in rural, low-income areas some 0.1% of affected infants may suffer intracranial bleeding. Late VKDB is largely preventable with parenteral vitamin K providing the best protection. The efficacy of oral prophylaxis is related to the dose and frequency of administration. Most multi-dose oral regimens provide protection for all except a small reservoir of infants with undetected hepatobiliary disease. Targeted surveillance of high-risk groups (e.g. biliary atresia) offers a novel approach to assess efficacy of prophylaxis.

Prevention of vitamin K deficiency bleeding in breastfed infants: lessons from the Dutch and Danish biliary atresia registries

OBJECTIVE

Newborns routinely receive vitamin K to prevent vitamin K deficiency bleeding. The efficacy of oral vitamin K administration may be compromised in infants with unrecognized cholestasis. We aimed to compare the risk of vitamin K deficiency bleeding under different prophylactic regimens in infants with biliary atresia.

PATIENTS AND METHODS

From Dutch and Danish national biliary atresia registries, we retrieved infants who were either breastfed and received 1 mg of oral vitamin K at birth followed by 25 microg of daily oral vitamin K prophylaxis (Netherlands, 1991-2003), 2 mg of oral vitamin K at birth followed by 1 mg of weekly oral prophylaxis (Denmark, 1994 to May 2000), or 2 mg of intramuscular prophylaxis at birth (Denmark, June 2000-2005) or were fed by formula. We determined the absolute and relative risk of severe vitamin K deficiency and vitamin K deficiency bleeding on diagnosis in breastfed infants on each prophylactic regimen and in formula-fed infants.

RESULTS

Vitamin K deficiency bleeding was noted in 25 of 30 of breastfed infants on 25 microg of daily oral prophylaxis, in 1 of 13 on 1 mg of weekly oral prophylaxis, in 1 of 10 receiving 2 mg of intramuscular prophylaxis at birth, and in 1 of 98 formula-fed infants (P < .001). The relative risk of a bleeding in breastfed compared with formula-fed infants was 77.5 for 25 microg of daily oral prophylaxis, 7.2 for 1 mg of weekly oral prophylaxis, and 9.3 for 2 mg of intramuscular prophylaxis at birth.

CONCLUSIONS

A daily dose of 25 microg of vitamin K fails to prevent bleedings in apparently healthy infants with unrecognized cholestasis because of biliary atresia. One milligram of weekly oral prophylaxis offers significantly higher protection to these infants and is of similar efficacy as 2 mg of intramuscular prophylaxis at birth. Our data underline the fact that event analysis in specific populations at risk can help to evaluate and improve nationwide prophylactic regimens.

Incidence of late vitamin K deficiency bleeding in newborns in the Netherlands in 2005: evaluation of the current guideline

Vitamin K prophylaxis is recommended to prevent the hazard of haemorrhage caused by vitamin K deficiency in newborns. The present Dutch guideline recommends 1 mg of vitamin K(1) orally at birth, followed by a daily dose of 25 microg of vitamin K(1) from 1 to 13 weeks of age for breastfed infants. Since the introduction of this prophylaxis, the incidence of vitamin K deficiency bleeding (VKDB) has decreased; however, late VKDB is still reported. From 1 January to 31 December 2005, a nationwide active surveillance was performed by the Netherlands Paediatric Surveillance Unit (NSCK) to study the current incidence and aetiology of late VKDB in infants. Six cases could be validated as late VKDB: all were breastfed, one fatal idiopathic intracranial haemorrhage at the age of 5 weeks and five bleedings secondary to an underlying cholestatic liver disease between the age of 3 and 7 weeks. The total incidence of late VKDB and idiopathic late VKDB was calculated to be 3.2 (95% CI: 1.2-6.9) and 0.5 (95% CI: 0-2.9) per 100,000 live births, respectively. With the current Dutch guideline, idiopathic late VKDB is rare but late VKDB secondary to cholestasis still occurs in breastfed infants. Doubling the daily dose of vitamin K(1) to 50 microg, as is comparable to formula-feeding, may possibly prevent VKDB in this group. Further research, however, is needed to prove this hypothesis.

Vitamin K deficiency bleeding: the readiness is all

Perspective on the papers by Busfield et al and McNinch et al (see pages 754 and 759 )

Prevalence of vitamin K deficiency in children with mild to moderate chronic liver disease

OBJECTIVES

Children with chronic liver disease are at risk for vitamin K deficiency because of fat malabsorption and inadequate dietary intake. The objective of this study was to determine the prevalence of vitamin K deficiency in children with mild to moderate chronic cholestatic and noncholestatic liver disease.

METHODS

Vitamin K status was examined in 43 children (0.25-15.9 years) with mild to moderate chronic cholestatic liver disease, 29 children (0.9-16.9 years) with chronic mild to moderate noncholestatic liver disease, and in 44 healthy children (1-18 years). Vitamin K status was assessed by the plasma PIVKA-II (protein induced in vitamin K absence) assay (enzyme-linked immunosorbent assay). Plasma PIVKA-II values greater than 3 ng/mL are indicative of vitamin K deficiency.

RESULTS

The mean plasma PIVKA-II (+/-SD) in cholestatic, noncholestatic, and healthy children was 61.9 +/-144, 1.2 +/- 3, and 2.1 +/- ng/mL, respectively (P < 0.002). Fifty-four percent of the children supplemented with vitamin K had plasma PIVKA-II greater than 3 ng/mL. Plasma conjugated bilirubin, total bile acids, and severity of liver disease were positively correlated with plasma PIVKA-II levels (P < 0.05).

CONCLUSIONS

Vitamin K deficiency is prevalent in children with mild to moderate chronic cholestatic liver disease, even with vitamin K supplementation. Elevated PIVKA-II levels occurred in children with a normal prothrombin, indicating that more sensitive markers of vitamin K status should be used in children with chronic liver disease. Vitamin K deficiency was related to degree of cholestasis and severity of liver disease in children. Children without cholestasis did not exhibit vitamin K deficiency.

Vitamin K prophylaxis: leaving the old route for the new one?

Oral or parenteral administration of vitamin K is the accepted practice for prevention of early vitamin K deficiency bleeding (VKDB) in the newborn. However, vitamin K prophylaxis in the newborn continues to be a worldwide health concern, particularly in breastfed infants. This paper reviews the current status of the use of vitamin K for the prevention of early and late VKDB.

Pharmacokinetics and efficacy of oral versus intravenous mixed-micellar phylloquinone (vitamin K1) in severe acute liver disease

BACKGROUND/AIMS

In patients with severe acute liver dysfunction, i.v. phylloquinone (vitamin K1) may be given to exclude vitamin K deficiency, rather than impaired hepatic synthesis of coagulation factors alone, as the cause of the coagulopathy. However, there have been no studies of the pharmacokinetics or efficacy of i.v. or oral K1 in such patients.

METHODS

49 adults with severe acute liver disease were randomised double-blind to a single 10 mg dose of i.v. or oral mixed-micellar K(1), or placebo. Serum levels of phylloquinone and undercarboxylated prothrombin (PIVKA-II) were assessed before and after treatment.

RESULTS

At admission, 13 patients (27%) had either low serum K1 levels or elevated PIVKA-II concentrations, indicative of subclinical vitamin K deficiency. In the 16 patients who received i.v. K1, there was one (6%) treatment failure (K1 rise <10 ng/ml above baseline), compared with 12 of the 15 (80%) who received oral K1 (P<0.0001). One patient in the placebo group developed overt vitamin K deficiency.

CONCLUSIONS

A minority of patients with severe acute liver dysfunction have subclinical vitamin K deficiency at the time of presentation, which is corrected by a single dose of i.v. K1. The intestinal absorption of mixed-micellar K1 is unreliable in adults with severe acute liver dysfunction.

Canadian Paediatric Surveillance Program confirms low incidence of hemorrhagic disease of the newborn in Canada

OBJECTIVES

To determine the incidence of hemorrhagic disease of the newborn (HDNB) in Canada and its relationship to the administration of vitamin K(1) (hereafter referred to as vitamin K) following birth.

METHODS

The Canadian Paediatric Surveillance Program sent monthly surveys to over 2100 Canadian paediatricians requesting identification of infants with defined criteria for HDNB. Reports were confirmed with subsequent case-specific data, including coagulation test results.

RESULTS

Of the 26 reports (10 in 1997, eight in 1998, four in 1999, four in 2000), two were from before the start of the study, three were duplicate reports, four cases erroneously identified hemolytic disease of the newborn, three had coagulation studies which were normal or not done, and seven had other disorders with bleeding. Of the six confirmed cases of infants with HDNB (one classic, five late), all had intracranial bleeding and five suffered neurological sequelae. The estimated incidence of HDNB in Canada (including infants who had oral vitamin K prophylaxis or did not receive vitamin K) is approximately 0.45/100,000.

CONCLUSION

This study confirmed the relatively low incidence of HDNB in Canada and validated the Canadian Paediatric Society's recommendation that all newborns should be given intramuscular vitamin K shortly following birth. To alleviate confusion with haemolytic disease of the newborn, Britain and Australia modified the title of their subsequent HDNB study to vitamin K deficiency bleeding.

Prevention of vitamin K deficiency bleeding with oral mixed micellar phylloquinone: results of a 6-year surveillance in Switzerland

In 1995, a new form of vitamin K prophylaxis with two oral doses of 2 mg mixed micellar phylloquinone (Konakion MM) on the 1st and 4th day of life was introduced in Switzerland. It was hoped that this new galenic preparation of phylloquinone would protect infants with insufficient or absent bile acid excretion from late vitamin K deficiency bleeding (VKDB). Subsequently, the occurrence of VKDB was monitored prospectively between July 1, 1995 and June 30, 2001 with the help of the Swiss Paediatric Surveillance Unit (SPSU). Over a period of 6 years (475,000 deliveries), there were no cases of early (<24 h of age), one case of classical (2-7 days of life), and 18 cases of late (1-12 weeks) VKDB fulfilling standard case definitions. In 13/18 patients with late VKDB there was pre-existing liver disease and in 4/18 patients, parents had refused prophylaxis. The incidence of late VKDB for infants with completed Konakion MM prophylaxis was 2.31/100,000 (95% CI: 1.16-4.14) and for the entire population 3.79/100,000 (95% CI: 2.24-5.98). There was only one case of late VKDB after complete prophylaxis in an infant without underlying liver disease.

CONCLUSION

two oral doses of 2 mg of a mixed micellar vitamin K preparation failed to abolish VKDB. The recommendations for vitamin K prophylaxis in Switzerland have therefore been changed to include a third dose at 4 weeks of age. Starting on January 1, 2004, the incidence of vitamin K deficiency bleeding will again be monitored prospectively by the Swiss Paediatric Surveillance Unit.

Vitamin K--what, why, and when

Policies for giving babies vitamin K prophylactically at birth have been dictated, over the last 60 years, more by what manufacturers decided on commercial grounds to put on the market, than by any informed understanding of what babies actually need, or how it can most easily be given. By a pure fluke a 1 mg IM dose, designed to prevent early vitamin deficiency bleeding ("haemorrhagic disease of the newborn") has been found to protect against late deficiency bleeding-a condition unrecognised at the time this policy took hold. Alternative strategies for oral prophylaxis are now opening up (see pp 109 and 113), but these are also, at the moment, dictated more by what the manufacturers choose to provide than by what would make for ease of delivery either in poor countries, or in the developed world.