Exclusively breastmilk-fed preterm infants are at high risk of developing subclinical vitamin K deficiency despite intramuscular prophylaxis at birth.

BACKGROUND: There is near-global consensus that all newborns be given parenteral vitamin K1 (VK1 ) at birth as prophylaxis against VK deficiency bleeding (VKDB). Breastmilk has a low VK content and cases of late VKDB are reported in exclusively breastmilk-fed preterm infants despite VK prophylaxis at birth. OBJECTIVES: To assess the prevalence of functional VK insufficiency in preterm infants based on elevated under-γ-carboxylated (Glu) species of Gla proteins, factor II (PIVKA-II), and osteocalcin (GluOC), synthesized by liver and bone, respectively. PATIENTS/METHODS: Prospective, multicenter, observational study in preterm infants born <33 weeks' gestation. Blood samples and dietary history were collected before hospital discharge, and after discharge at 2-3 months' corrected age. Outcome measures were serum VK1 , PIVKA-II, and %GluOC (GluOC as a percentage of the sum of GluOC plus GlaOC) compared between exclusively breastmilk-fed and formula/mixed-fed infants after discharge. RESULTS: After discharge, breastmilk-fed babies had significantly lower serum VK1 (0.15 vs. 1.81 µg/L), higher PIVKA-II (0.10 vs. 0.02 AU/ml) and higher %GluOC (63.6% vs. 8.1%) than those receiving a formula/mixed-feed diet. Pre-discharge (based on elevated PIVKA-II), only one (2%) of 45 breastmilk-fed infants was VK insufficient. After discharge, eight (67%) of 12 exclusively breastmilk-fed babies were VK insufficient versus only one (4%) of 25 formula/mixed-fed babies. CONCLUSIONS: Preterm infants who remain exclusively or predominantly human breastmilk-fed after neonatal unit discharge are at high risk of developing subclinical VK deficiency in early infancy. Routine postdischarge VK1 supplementation of breastfed infants to provide intakes comparable to those from formula milks should prevent this deficiency.

Switching from Warfarin to rivaroxaban induces sufficiency of vitamin K and reduction of arterial stiffness in patients with atrial fibrillation.

Use of chronic vitamin K antagonist (VKA) induces a long-term deficiency of vitamin K, which may cause arterial stiffness and bone-related disease. Switching from VKA to rivaroxaban could induce rapid sufficiency of vitamin K and improvement of arterial stiffness. The K2 SUMMIT-3 study is a multicenter, open-label, prospective, and randomized design. Patients with atrial fibrillation who have been taking VKA for more than 6 months but less than 10 years were randomly assigned to two groups; those switching from VKA to rivaroxaban and those continuing with VKA medication. The primary endpoint was the percentage difference of brachial-ankle pulse wave velocity (baPWV) in 3 months. A total of 77 patients were randomly assigned to receive rivaroxaban (n = 38) or VKA (n = 39). The average age was 74 ± 9 years. The duration for which VKA was prescribed prior to randomization was 90 ± 87 months.Abnormally high levels of Des-gamma carboxyprothrombin (PIVKA-II) or uncarboxylated osteocalcin (ucOC) indicating vitamin K insufficiency were observed in 100% or 82% of the patients at baseline but it reduced to 2% (p < 0.0001) or 55% (p = 0.01) at 3 months in the rivaroxaban group. To the contrary, theses data had no changes in the VKA group. The percentage difference in baPWV was - 1.4 ± 10.0% vs. 3.5 ± 14.7% in the rivaroxaban and the VKA groups, respectively. (p = 0.02). Switching from VKA to rivaroxaban resulted in rapid sufficiency of vitamin K and reduction of arterial stiffness in 3 months.

Vitamin K2 Needs an RDI Separate from Vitamin K1.

Vitamin K and its essential role in coagulation (vitamin K [Koagulation]) have been well established and accepted the world over. Many countries have a Recommended Daily Intake (RDI) for vitamin K based on early research, and its necessary role in the activation of vitamin K-dependent coagulation proteins is known. In the past few decades, the role of vitamin K-dependent proteins in processes beyond coagulation has been discovered. Various isoforms of vitamin K have been identified, and vitamin K2 specifically has been highlighted for its long half-life and extrahepatic activity, whereas the dietary form vitamin K1 has a shorter half-life. In this review, we highlight the specific activity of vitamin K2 based upon proposed frameworks necessary for a bioactive substance to be recommended for an RDI. Vitamin K2 meets all these criteria and should be considered for a specific dietary recommendation intake.

Multicenter Randomized Controlled Trial of Vitamin K Antagonist Replacement by Rivaroxaban with or without Vitamin K2 in Hemodialysis Patients with Atrial Fibrillation: the Valkyrie Study.

BACKGROUND: Vitamin K antagonists (VKAs), although commonly used to reduce thromboembolic risk in atrial fibrillation, have been incriminated as probable cause of accelerated vascular calcification (VC) in patients on hemodialysis. Functional vitamin K deficiency may further contribute to their susceptibility for VC. We investigated the effect of vitamin K status on VC progression in 132 patients on hemodialysis with atrial fibrillation treated with VKAs or qualifying for anticoagulation. METHODS: Patients were randomized to VKAs with target INR 2-3, rivaroxaban 10 mg daily, or rivaroxaban 10 mg daily plus vitamin K2 2000 µg thrice weekly during 18 months. Systemic dp-ucMGP levels were quantified to assess vascular vitamin K status. Cardiac and thoracic aorta calcium scores and pulse wave velocity were measured to evaluate VC progression. RESULTS: Baseline dp-ucMGP was severely elevated in all groups. Initiation or continuation of VKAs further increased dp-ucMGP, whereas levels decreased in the rivaroxaban group and to a larger extent in the rivaroxaban+vitamin K2 group, but remained nevertheless elevated. Changes in coronary artery, thoracic aorta, and cardiac valve calcium scores and pulse wave velocity were not significantly different among the treatment arms. All cause death, stroke, and cardiovascular event rates were similar between the groups. Bleeding outcomes were not significantly different, except for a lower number of life-threatening and major bleeding episodes in the rivaroxaban arms versus the VKA arm. CONCLUSIONS: Withdrawal of VKAs and high-dose vitamin K2 improve vitamin K status in patients on hemodialysis, but have no significant favorable effect on VC progression. Severe bleeding complications may be lower with rivaroxaban than with VKAs.

Prophylactic Vitamin K Administration in Neonates on Prolonged Antibiotic Therapy: A Randomized Controlled Trial.

OBJECTIVE: To compare the prevalence of vitamin K deficiency after intramuscular vitamin K or no treatment in neonates with sepsis on prolonged (>7 days) antibiotic therapy. STUDY DESIGN: Open label randomized controlled trial. SETTING: Level 3 Neonatal Intensive Care Unit (NICU). PARTICIPANTS: Neonates with first episode of sepsis on antibiotics for ≥7 days were included. Neonates with clinical bleeding, vitamin K prior to start of antibiotic therapy (except the birth dose), cholestasis or prenatally diagnosed bleeding disorder were excluded. INTERVENTIONS: Randomized to receive 1 mg vitamin K (n=41) or no vitamin K (n=39) on the 7th day of antibiotic therapy. MAIN OUTCOME MEASURES: Vitamin K deficiency defined as Protein Induced by Vitamin K Absence (PIVKA-II) >>2 ng/mL after 7 ± 2 days of enrolment. RESULTS: The prevalence of vitamin K deficiency was 100% (n=80) at enrolment and it remained 100% even after 7 ± 2 days of enrolment in both the groups. CONCLUSIONS: Neonates receiving prolonged antibiotics have universal biochemical vitamin K deficiency despite vitamin K administration on 7th day of antibiotic therapy.

[CURRENT APPROACHES TO PREVENTION OF BLEEDINGS, ASSOCIATED WITH VITAMIN K DEFICIENCY IN NEWBORNS AND INFANTS].

In the article intended for neonatologists, general practitioners and family doctors, the main causes of hemostatic disorders that lead to the development of hemorrhagic syndrome in newborns and infants are given. The emphasis is on the different forms of neonatal hemorrhagic disease (HD), which is based on the deficiency of vitamin K1, and therefore the bleeding that is observed in children who are breastfed in the first half of life is mostly associated, namely, with vitamin K deficiency. Risk factors of HD depending from the time of the beginning, of the action of one or another factor. The main clinical manifestations of both early and late forms of HD are described, it is shown which of them are mistakenly diagnosed that lead to the appointment of the wrong treatment. The assessment of the need for prevention of late form of bleeding associated with vitamin K deficiency is carried out by determining the concentration in the blood of a functional coagulation marker - PIVKA II. Modern methods of prevention of late bleeding associated with vitamin K1 deficiency, based on nosological units - chronic cholestasis, cystic fibrosis, are presented. The current recommendations on the use of vitamin K1 in newborns and infants of the American Academy of Pediatrics, the scientific community of Canada, Netherlands, Switzerland, Germany, France, the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), the World Health Organization, which are clearly followed by the effects of local peculiarities are described and interpreted. on approaches to the prevention of bleeding associated with vitamin K1 deficiency, which affects the choice of a single dose, the duration of the prophylactic course and the route of administration of vitamin in K1 (phytomenadion). The role of parents in the prevention of vitamin K deficiency is emphasized.

The Strategy to Prevent and Regress the Vascular Calcification in Dialysis Patients.

The high prevalence of arterial calcification in end-stage renal disease (ESRD) is far beyond the explanation by common cardiovascular risk factors such as aging, diabetes, hypertension, and dyslipidemia. The finding relies on the fact that vascular and valvular calcifications are predictors of cardiovascular diseases and mortality in persons with chronic renal failure. In addition to traditional cardiovascular risk factors such as diabetes mellitus and blood pressure control, other ESRD-related risks such as phosphate retention, excess calcium, and prolonged dialysis time also contribute to the development of vascular calcification. The strategies are to reverse "calcium paradox" and lower vascular calcification by decreasing procalcific factors including minimization of inflammation (through adequate dialysis and by avoiding malnutrition, intravenous labile iron, and positive calcium and phosphate balance), correction of high and low bone turnover, and restoration of anticalcification factor balance such as correction of vitamin D and K deficiency; parathyroid intervention is reserved for severe hyperparathyroidism. The role of bone antiresorption therapy such as bisphosphonates and denosumab in vascular calcification in high-bone-turnover disease remains unclear. The limited data on sodium thiosulfate are promising. However, if calcification is to be targeted, ensure that bone health is not compromised by the treatments.

Total and Differential Phylloquinone (Vitamin K1) Intakes of Preterm Infants from All Sources during the Neonatal Period.

All newborns require phylloquinone after birth to prevent vitamin K deficiency bleeding. Babies born prematurely may be at particular risk of deficiency without adequate supplementation during infancy. The main sources of phylloquinone in preterm babies during the neonatal period are the prophylactic dose of phylloquinone given at birth, and that derived from parenteral and/or enteral feeding. This observational study formed part of a prospective, multicentre, randomised, controlled trial that examined the vitamin K status of preterm infants after random allocation to one of three phylloquinone prophylactic regimens at birth (0.5 or 0.2 mg intramuscularly or 0.2 mg intravenously). In this nutritional sub-study we quantified the proportional and total phylloquinone intakes of preterm infants within the neonatal period from all sources. Almost all infants had average daily phylloquinone intakes that were in excess of the currently recommended amounts. In infants who did not receive parenteral nutrition, the bolus dose of phylloquinone given at birth was the major source of phylloquinone intake, whereas in infants who received parenteral nutrition, the intake from the parenteral preparation exceeded that from the bolus dose by a ratio of approximately 3:1. Our study supports the concern of others that preterm infants who receive current parenteral nutrition formulations may be receiving excessive vitamin K.

High intra- and inter-individual variability of plasma vitamin K concentrations in patients with atrial fibrillation under warfarin therapy.

BACKGROUND/OBJECTIVES: Vitamin K intake is considered as a controllable contributor to warfarin sensitivity. It is restricted in warfarin-treated patients. However, little study has assessed the vitamin K status in warfarin-treated patients. We directly measured plasma vitamin K in warfarin-treated patients and evaluated its effect on anticoagulation. SUBJECTS/METHODS: A total of 302 plasma vitamin K concentrations were assessed using high-performance liquid chromatography for 203 outpatients with atrial fibrillation under warfarin treatment. Clinical and laboratory information including warfarin dosage, plasma warfarin concentrations, prothrombin time international normalized ratio (PT INR) and CYP2C9/VKORC1 genotypes was reviewed retrospectively. The anticoagulation stability (intra-individual variability, frequency of PT INR tests and complications) was investigated in 163 patients with long-term warfarin therapy. Plasma vitamin K was measured in 40 healthy subjects and in 40 patients before and after initial warfarin treatment. RESULTS: Vitamin K concentrations were significantly decreased after the initiation of warfarin treatment (before treatment: 1.72 ng/ml; after treatment: 0.59 ng/ml, P<0.05). There was a large inter-individual variability in vitamin K levels (0.2-4.2 ng/ml) in warfarin-treated patients. PT INR was more frequently checked in patients with low plasma vitamin K levels than in those with high vitamin K levels (9.5 times/year vs 7.5 times/year, P=0.029). Two patients with gross hematuria showed very low vitamin K levels (<0.4 ng/ml). CONCLUSIONS: We found high inter- and intra-individual variability in vitamin K concentration in warfarin-treated patients. Low vitamin K concentration in warfarin-treated patients suggested excessive dietary restriction. Plasma vitamin K measurement would be helpful for dietary control and anticoagulation stability.

Role of prophylactic vitamin K in preventing antibiotic induced hypoprothrombinemia.

OBJECTIVE: To determine prophylactic role of single dose of vitamin K in prevention of antibiotic induced hypoprothrombinemia. METHODS: This prospective comparative study included critically ill children in age group 2 mo to 12 y, admitted to a tertiary care hospital in India, likely to receive prolonged antibiotic therapy. One hundred twenty children, 60 in each group (A & B) were enrolled in the study. Patient allocation was done on alternate basis. Group A children received prophylactic vitamin K while group B did not. Baseline coagulation studies and other investigations were done in all children. Coagulation studies were repeated on day 10 and day 14 of antibiotic therapy and in between if required clinically. Children who developed deranged INR were given therapeutic vitamin K. If deranged INR returns to normal at 12 h of vitamin K administration then it indirectly confirms vitamin K deficiency. Analysis was done by fisher's t test and chi square test. RESULTS: In children on prolonged antibiotic therapy, vitamin K deficiency was a common problem (15%). It was common in male sex, severe grade of protein energy malnutrition (PEM), N-methylthiotetrazole (NMTT) group containing antibiotics use and duration of antibiotic more than 10 d. It was same in children whether they received or did not receive prophylactic vitamin K on day 1 of antibiotic therapy (95% CI; p value 0.79). CONCLUSIONS: Vitamin K deficiency is common problem in patients on prolonged antibiotic therapy. There is no role of single dose of prophylactic vitamin K in preventing antibiotic induced hypoprothrombinemia.

Vitamin K1 monitoring in pregnancies after bariatric surgery: a prospective cohort study.

BACKGROUND: Neonatal intracranial bleedings and birth defects have been reported, possibly related to maternal vitamin K1 deficiency during pregnancy after bariatric surgery. The objective of this study was to investigate the effects of screening and supplementation on K1 serum levels in pregnant women with bariatric surgery, and to compare K1 levels and prothrombin time (PT %) in the first trimester with pregnant women without bariatric surgery. METHODS: A prospective cohort study including 49 pregnant women with bariatric surgery. Nutritional deficiencies were prospectively screened. In case of observed low K1 serum levels, supplementation was provided. K1 serum levels and PT (%) during the first trimester were compared with a nonsurgical control group of 27 women. RESULTS: During the first trimester, most women had low K1 serum levels (<0.8 nmol/l). Mean vitamin K1 levels were significantly lower in the surgical group compared to the nonsurgical control group (.44 versus .64 nmol/l; P = .016). PT (%) remained in the normal range, The surgery group showed a higher mean PT compared to the controls (111.3 versus 98.9%; P<.001) Mean K1 serum levels in the study group were higher during the third than during the first trimester (P = .014). PT (%) was significantly higher during the second and third than during the first trimester (P = .004). Most of the coagulation factors, including II, V, VII, IX, and X, remained within normal ranges. CONCLUSION: Low circulating K1 appears to be common in pregnant women with and without bariatric surgery. Supplementation during pregnancy can restore vitamin K1 in women with bariatric surgery, potentially protecting the fetus and newborn against intracranial hemorrhage.

Rise in late onset vitamin K deficiency bleeding in young infants because of omission or refusal of prophylaxis at birth.

BACKGROUND: Newborns are at risk for vitamin K deficiency and subsequent bleeding unless supplemented at birth. Vitamin K deficiency bleeding is an acquired coagulopathy in newborn infants because of accumulation of inactive vitamin K-dependent coagulation factors, which leads to an increased bleeding tendency. Supplementation of vitamin K at birth has been recommended in the United States since 1961 and successfully reduced the risk of major bleeding. Refusal or omission of vitamin K prophylaxis is increasing and puts newborn infants at risk for life-threatening bleeding. PATIENTS: Over an eight month period, we encountered seven infants with confirmed vitamin K deficiency; five of these patients developed vitamin K deficiency bleeding. RESULTS: The mean age of the seven infants with vitamin K deficiency was 10.3 weeks (range, 7-20 weeks); manifestations ranged from overt bleeding to vomiting, poor feeding, and lethargy. None of the infants had received vitamin K at birth, and all were found to have profound derangement of coagulation parameters, which corrected rapidly with administration of vitamin K in IV or intramuscular form. Four of the seven infants had intracranial hemorrhage; two of these infants required urgent neurosurgical intervention. CONCLUSION: Supplementation of vitamin K at birth for all newborns prevents major hemorrhagic complications, such as intracranial bleeding, due to vitamin K deficiency. Parental refusal of vitamin K is increasingly common. It is critical that health care providers and the public be made aware of the varied presentation of this preventable acquired coagulopathy.

Vitamin K and bone health in older adults.

Vitamin K is one of several nutrients that have been linked with bone health. In particular, there is an emerging literature regarding the questionable efficacy of vitamin K supplementation in reducing age-related bone loss. This review aims to summarize the role of vitamin K in bone health in older adults and discuss the clinical implications from a select few human studies. The evidence for vitamin K supplementation in older adults is mixed. Although the observational studies have shown linkages between vitamin K intake and lower risk of fractures in this population, the current evidence from randomized controlled trials is not strongly supportive of vitamin K supplementation in older adults for the intent of improving bone health.