Vitamin K

Protein C deficiency in microvascular head and neck reconstruction

OBJECTIVE

To determine the incidence of perioperative protein C deficiency in patients undergoing free flap reconstruction of cancer-related defects in the head and neck.

STUDY DESIGN

Prospective case series.

INTERVENTION

Ten patients underwent microvascular reconstruction after surgical therapy of carcinomas of the oral cavity or oropharynx. Coagulation studies were determined in all patients 72 hours after surgery.

SETTING

Academic tertiary care medical center

RESULTS

Protein C deficiency was detected in 70% of patients. One free flap failure was attributed to protein C deficiency.

CONCLUSIONS

Vitamin K-dependent clotting factors are frequently deficient during the postoperative period after major head and neck surgery, which may result in a state of hypercoagulability. Protein C deficiency should be considered as a possible cause of free flap thrombosis in patients who undergo microvascular head and neck reconstruction.

Gender differences in hepatic phylloquinone and menaquinones in the vitamin K-deficient and -supplemented rat

Gender differences in relation to vitamin K were investigated in the rat. Hepatic phylloquinone and menaquinone (MK-1 to MK-10) concentrations, gamma-carboxyglutamic acid (Gla) excretion, plasma phylloquinone and percent prothrombin were measured in male and female rats on a chow diet (24.5 ng phylloquinone and 8.8 microgram menadione), and on phylloquinone-deficient and -supplemented purified diets (0.38 and 1400 ng phylloquinone/g, respectively). Mean hepatic phylloquinone concentrations varied with dietary intake and ranged from 6.8+/-9.0 pmol/g in the deficient male, to 171. 1+/-56.9 pmol/g in the supplemented female. Menaquinones accounted for a large proportion of total vitamin K in the liver of males and females with MK-4, MK-6, and MK-10 present in highest concentrations. On the chow and supplemented diets, females had significantly higher MK-4, MK-6, and MK-10 concentrations in their livers (P<0.05). On the phylloquinone-deficient diet (-K1), hepatic phylloquinone, MK-4, and to a lesser extent MK-6 (but not MK-10) were significantly reduced (P<0.05). In the phylloquinone-supplemented male and female groups, which did not receive menadione during the experimental period, MK-4 increased above that in the chow groups suggesting synthesis of MK-4 from phylloquinone which was statistically significant in the female (P<0.01). A significant gender difference (P<0.05) was also observed for urinary Gla excretion with less Gla excreted by the females indicating that females may require less dietary phylloquinone than males of the same body weight.

Vitamin K intake and hip fractures in women: a prospective study

BACKGROUND

Vitamin K mediates the gamma-carboxylation of glutamyl residues on several bone proteins, notably osteocalcin. High serum concentrations of undercarboxylated osteocalcin and low serum concentrations of vitamin K are associated with lower bone mineral density and increased risk of hip fracture. However, data are limited on the effects of dietary vitamin K.

OBJECTIVE

We investigated the hypothesis that high intakes of vitamin K are associated with a lower risk of hip fracture in women.

DESIGN

We conducted a prospective analysis within the Nurses' Health Study cohort. Diet was assessed in 72327 women aged 38-63 y with a food-frequency questionnaire in 1984 (baseline). During the subsequent 10 y of follow-up, 270 hip fractures resulting from low or moderate trauma were reported.

RESULTS

Women in quintiles 2-5 of vitamin K intake had a significantly lower age-adjusted relative risk (RR: 0.70; 95% CI: 0.53, 0.93) of hip fracture than women in the lowest quintile (< 109 microg/d). Risk did not decrease between quintiles 2 and 5 and risk estimates were not altered when other risk factors for osteoporosis, including calcium and vitamin D intakes, were added to the models. Risk of hip fracture was also inversely associated with lettuce consumption (RR: 0.55; 95% CI: 0.40, 0.78) for one or more servings per day compared with one or fewer servings per week), the food that contributed the most to dietary vitamin K intakes.

CONCLUSIONS

Low intakes of vitamin K may increase the risk of hip fracture in women. The data support the suggestion for a reassessment of the vitamin K requirements that are based on bone health and blood coagulation.

The effect of diet on blood vitamin K status and urinary mineral excretion assessed by a food questionnaire

To assess Vitamin K (VK) status by food questionnaire, healthy young males (32) and females (9) were given a food list of 50 VK rich foods (identified in the 4th edition standard tables of food composition in Japan). After checking the food names and approximate amount eaten for 7 days, early morning blood and urine samples were collected. Prothrombin and hepaplastin was tested and plasma protein induced by VK absence factor II (PIVKA-II), osteocalcin, and calcium, phosphorous and magnesium in plasma and urine were determined. Participants who have a habit of eating natto, a traditional Japanese food very rich in Vitamin K, VK were excluded, and lowest and highest VK consumers were compared (males; lowest 7 vs. highest 7, females; 3 vs. 3). Plasma PIVKA-II levels, and urinary calcium and magnesium excretion of the lowest was significantly higher, but urinary phosphorus was lower, than that of the highest in females. In the natto eaters, daily mean VK intakes and hepaplastin test results of natto eaters were significantly higher, but urinary calcium excretions were lower than that of non natto eaters in males. These results suggest that Daily VK intake estimated from a questionnaire, is well related to real VK status, and also that natto is a good dietary source of vitamin K.

Effect of vitamin K1 on glucose-6-phosphate dehydrogenase deficient neonatal erythrocytes in vitro

AIM

To determine whether vitamin K1, which is routinely administered to neonates, could act as an exogenous oxidising agent and be partly responsible for haemolysis in glucose-6-phosphat-dehydrogenase (G-6-PD).

METHODS

G-6-PD deficient (n = 7) and control (n = 10) umbilical cord blood red blood cells were incubated in vitro with a vitamin K1 preparation (Konakion). Two concentrations of Vitamin K1 were used, both higher than that of expected serum concentrations, following routine injection of 1 mg vitamin K1. Concentrations of reduced glutathione (GSH) and methaemoglobin, indicators of oxidative red blood cell damage, were determined before and after incubation, and the mean percentage change from baseline calculated.

RESULTS

Values (mean (SD)) for GSH, at baseline, and after incubation with vitamin K1 at concentrations of 44 and 444 microM, respectively, and percentage change from baseline (mean (SD)) were 1.97 + 0.31 mumol/g haemoglobin, 1.89 +/- 0.44 mumol/g (-4.3 +/- 13.1%), and 1.69 +/- 0.41 mumol/g (-14.5 +/- 9.3%) for the G-6-PD deficient red blood cells, and 2.27 +/- 0.31 mumol/g haemoglobin, 2.09 +/- 0.56 mumol/g (-7.2 +/- 23.2%), and 2.12 +/- 0.38 mumol/g (-6.0 + 14.1%) for the control cells. For methaemoglobin (percentage of total haemoglobin), the corresponding values were 2.01 +/- 0.53%, 1.93 +/- 0.37% (-0.6 +/- 17.4%) and 2.06 +/- 0.43% (5.7 +/- 14.2%) for the G-6-PD deficient red blood cells, and 1.56 +/- 0.74%, 1.70 +/- 0.78% (12.7 +/- 21.9%), and 1.78 +/- 0.71% (20.6 +/- 26.8%) for the control red blood cells. None of the corresponding percentage changes from baseline was significantly different when G-6-PD deficient and control red blood cells were compared.

CONCLUSIONS

These findings suggest that G-6-PD deficient red blood cells are not at increased risk of oxidative damage from vitamin K1.

Management of acute liver failure

Acute liver failure represents one of the most challenging conditions in gastroenterology. In most cases, there is no effective therapy making supportive intensive care the most important management tool. These patients frequently develop multi-organ failure, placing them at risk of systemic infections, cerebral edema, hemodynamic instability, coagulopathy and various renal and metabolic complications. Successful management of the patient with acute liver failure requires an understanding of the pathophysiology and management of these complications. An overview of acute liver failure and its most common complications is presented.

Menatetrenone ameliorates osteopenia in disuse-affected limbs of vitamin D- and K-deficient stroke patients

Significant reduction in bone mineral density (BMD) occurs in stroke patients on the hemiplegic and contralateral sides, correlating with the degree of paralysis and vitamin D and K deficiency due to malnutrition, and increasing the risk of hip fracture. We evaluated the efficacy of vitamin K2 (menatetrenone: menaquinone-4; MK-4) in maintaining BMD by comparing serum biochemical indices of bone metabolism between treated and untreated patients. In a random and prospective study, of 108 hemiplegic patients following stroke, 54 received 45 mg menatetrenone daily (MK-4 group, n = 54) for 12 months, and the remaining 54 (untreatment group) did not. Nine patients excluded from the study. The BMD in the second metacarpals and serum indices of bone metabolism were determined. BMD on the hemiplegic side increased by 4.3% in the MK-4 group and decreased by 4.7% in the untreated group (p < 0.0001), while BMD on the intact side decreased by 0.9% in the MK-4 group and by 2.7% in the untreated group (p < 0.0001). At baseline, patients of both groups showed vitamin D and K1 deficiencies, high serum levels of ionized calcium, pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), and low levels of parathyroid hormones (PTH) and bone Gla proteins (BGP), indicating that immobilization-induced hypercalcemia inhibits renal synthesis of 1, 25-dihydroxyvitamin D (1, 25-[OH]2D) and compensatory PTH secretion. Both vitamins K1 and K2 increased by 97.6% and 666.9%, respectively, in the MK-4 group. Correspondingly, a significant increase in BGP and decreases in both ICTP and calcium were observed in the MK-4 group, in association with a simultaneous increase in both PTH and 1, 25-[OH]2D. One patient in the untreated group suffered from a hip fracture, compared with none in the MK-4 group. The treatment with MK-4 can increase the BMD of disused and vitamin D- and K-deficient hemiplegic bone by increasing the vitamin K concentration, and it also can decrease calcium levels through inhibition of bone resorption, resulting in an increase in 1, 25-[OH]2D concentration.

Dietary intake and adequacy of vitamin K

The current daily recommended dietary allowance for vitamin K is 1 microg/kg. Reliable measurements of vitamin K content in foods are now available, and data from 11 studies of vitamin K intake indicate that the mean intake of young adults is approximately 80 microg phylloquinone/d and that older adults consume approximately 150 microg/d. The vitamin K concentration in most foods is very low (<10 microg/100 g), and the majority of the vitamin is obtained from a few leafy green vegetables and four vegetable oils (soybean, cottonseed, canola and olive) that contain high amounts. Limited data indicate that absorption of phylloquinone from a food matrix is poor. Hydrogenated oils also contain appreciable amounts of 2', 3'-dihydrophylloquinone of unknown physiological importance. Menaquinones absorbed from the diet or the gut appear to provide only a minor portion of the human daily requirement. Measures of the extent to which plasma prothrombin or serum osteocalcin lack essential gamma-carboxyglutamic acid residues formed by vitamin K action, or the urinary excretion of this amino acid, provide more sensitive measures of vitamin K status than measures of plasma phylloquinone or insensitive clotting assays.

Lipids and lipid-activated vitamins in chronic cholestatic diseases

Primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune cholangiopathy are cholestatic liver diseases of unknown cause. Destruction of small to medium bile ducts (in primary biliary cirrhosis and autoimmune cholangiopathy) and large bile ducts (in primary sclerosing cholangitis) leads to progressive cholestasis, liver failure and end-stage liver disease. A variety of abnormalities in lipid metabolism have been described in primary biliary cirrhosis, and range from alterations in serum lipid levels and lipoprotein subsets to deranged metabolism of cholesterol. Progressive cholestasis and, consequently, decreased small intestinal bile acid concentrations in these cholestatic liver disease can also lead to impaired absorption of fats and fat-soluble vitamins, resulting in steatorrhea and deficiencies in vitamins A, D, E, and K. This article focuses on abnormalities in lipid metabolism in primary biliary cirrhosis and primary sclerosing cholangitis, and on lipid-activated vitamin deficiencies in these disorders.

Fat-soluble vitamins in patients with acute renal failure

OBJECTIVE

Systematic investigations on the status of fat-soluble vitamins in patients with acute renal failure (ARF) are lacking and hence no recommendations for vitamin supply can be defined for these subjects. Thus we compared the status of fat-soluble vitamins, of transport molecules and some vitamin-dependent proteins in patients with ARF and healthy controls.

SETTING

Nephrology unit of a university hospital.

PATIENTS AND METHODS

Eight patients with ARF requiring hemodialysis therapy were investigated and 28 healthy volunteers served as controls. Plasma concentrations of retinol (vitamin A) and retinol-binding protein (RBP), 25-OH and 1,25-(OH)2 vitamin D3, of parathyroid hormone (PTH), of alpha-tocopherol (vitamin E) and of phylloquinone (vitamin K), osteocalcin and noncarboxylated osteocalcin, respectively, were measured and plasma lipoprotein fractions (as vitamin transport vehicle) were evaluated.

RESULTS

Vitamin A levels were decreased (p < 0.001), but RBP levels were normal in ARF patients. Vitamin D3 metabolites 25-OH and 1,25-(OH)2 vitamin D3 plasma levels were profoundly depressed, and PTH was elevated (p < 0.001). Vitamin E plasma concentration was reduced (p < 0.001) but this cannot be accounted for by decreased LDL cholesterol or triglyceride levels. In contrast, vitamin K plasma level was rather elevated in ARF patients with a broad range of individual values. Blood coagulation was normal but total and carboxylated osteocalcin were decreased. No correlation of vitamin K concentrations and any of the plasma lipoprotein fractions could be identified.

CONCLUSION

With the exception of vitamin K, profound deficiencies of fat-soluble vitamins develop in patients with ARF. Current recommendations for vitamin supplementation are inadequate and should be reevaluated for these patients.

Is vitamin K1 supplementation necessary in long-term parenteral nutrition?

BACKGROUND

I.v. lipid emulsions contain vitamin K in substantial quantities and in 1989, we therfore stopped supplying vitamin K1 to patients receiving home parenteral nutrition (HPN).

METHODS

Nine patients (group I) receiving HPN before 1989 (10 mg i.v. vitamin K1 supplementation weekly until 1989, which was discontinued thereafter) and six patients with an initial low plasma vitamin K1 concentration (related to their malabsorption) (group II) receiving HPN after 1989 were studied. Prothrombin time (PT), plasma vitamin K1 concentration, and vitamin K1, content in lipid emulsions were measured throughout the period of HPN.

RESULTS

All lipid emulsions, except for Eurolip 20% and Clinoleic 20% (Baxter SA, Maurepas, France) contained vitamin K1, with concentration ranges from 179 +/- 39 to 353 +/- 78 ng/L. Group I patients had an initial high plasma vitamin K1 concentration due to the vitamin K1 supplementation. After this supplementation was discontinued, plasma vitamin K1 decreased and remained in normal ranges with a normal PT. Throughout the HPN period after 1989, patients received 255 +/- 104 micrograms of vitamin K1 weekly through lipid emulsions. The PT and plasma vitamin K1 concentrations in group II patients were restored by lipid emulsions, which contained 418 +/- 143 micrograms/wk of vitamin K1.

CONCLUSIONS

In patients receiving i.v. lipids (except for Eurolip and Clinoleic), a normal vitamin K1 status can be maintained during long-term HPN without vitamin K1 supplementation. However, vitamin K supplementation cannot be abandoned until the vitamin K content of emulsions is standardized by manufacturers. A weekly supply of 250 to 400 micrograms of vitamin K1 is enough to maintain and even restore a normal vitamin K1 status in HPN.

Crohn's disease: nutrition and nutritional therapy

Disordered nutrition is common in Crohn's disease and is multifactorial. Regular and systematic monitoring of at least a minimum set of nutrition data is an essential component of care of children and adults with Crohn's disease. However, even in children, monitoring of growth and development may be deficient. Multiple macro- and micronutrient deficiencies are common in Crohn's disease, especially in those with extensive small bowel deficiencies or after multiple surgical resections. Body composition analysis may show differences from simple starvation, and metabolic effects of inflammation are increasingly being recognized. Nutritional support is part of the management of all patients with Crohn's disease, but nutritional intervention with defined formula liquid diet is an effective specific anti-inflammatory therapy. Although meta-analysis of published trials suggest that steroids are more effective than defined formula liquid diets, objective evidence from whole gut lavage fluid analysis and from faecal excretion of radiolabelled leukocytes shows unequivocal benefit of elemental diet based on measuring parameters of tissue damage. Enteral feeding with liquid diets should be considered in patients with incomplete small bowel obstruction, severe painful perianal disease, failure of corticosteroids in active Crohn's disease, borderline intestinal failure and in children with active Crohn's disease or with growth failure.

Decreased circulating levels of vitamin K and 25-hydroxyvitamin D in osteopenic elderly men

Changes in the circulating factors participating in involutional osteoporosis have been intensively investigated in women, but little is known about this in men. We investigated the possible participation of circulating factors including testosterone, vitamin D metabolites, and vitamins K1 and K2 in osteopenia in elderly men. In a group of 27 ambulatory men aged 74 +/- 10 years (mean +/- SD; range, 60 to 90), the bone mineral density (BMD) of the second to fourth lumbar vertebrae was measured by dual-energy x-ray absorptiometry (DXA) and expressed as a Z score, the age-adjusted BMD value for the Japanese population (mean +/- SD, 0 +/- 1). Although the plasma level of total testosterone significantly decreased with age in the group, it did not significantly correlate with the Z score. However, the plasma levels of 25-hydroxyvitamin D (25-OHD), phylloquinone, menaquinone-7 (MK-7), and albumin were significantly positively correlated with the Z score. Moreover, plasma 25-OHD and both phylloquinone and MK-7 were significantly positively correlated in the subjects. These observations suggest that depressed circulating levels of 25-OHD and vitamin K concomitantly and cooperatively participate in osteopenia in elderly men, which may reflect the etiology of the type II moiety of involutional osteoporosis.

Vitamin K prophylaxis in less developed countries: policy issues and relevance to breastfeeding promotion

Vitamin K prophylaxis prevents hemorrhagic disease of the newborn. The present review estimates the potential magnitude of this problem in less developed countries, assessing the need for prophylaxis, along with its cost-effectiveness and feasibility. Late hemorrhagic disease, occurring between 2 and 12 weeks, often leads to death or permanent disability. Its median incidence in developed countries is 7 per 100,000 births. Incidences in less developed countries may be much higher. Three incidence scenarios are proposed and the corresponding losses of disability-adjusted life-years (DALYs) calculated. Under the intermediate scenario, late hemorrhagic disease accounts for 0.1% to 0.2% of DALYs lost to children less than 5 years of age. Assuming a cost of +1.00 per injection, each DALY saved would cost +133. Decisions on prophylaxis must be made on a national basis, considering mortality levels and causes, health budgets, and feasibility. Comparison with the impact of diseases prevented by breast-feeding shows that concern with hemorrhagic disease should not affect breast-feeding promotion efforts, although strategies for supplementing breast-fed infants must be explored.

Long-term oral anticoagulation reduces bone mass in patients with previous hemispheric infarction and nonrheumatic atrial fibrillation

BACKGROUND AND PURPOSE

Vitamin K is an essential factor for synthesis of plasma clotting proteins and for site-specific carboxylation of bone Gla protein and other bone matrix proteins. Low vitamin K has been associated with reduced bone mineral density. Warfarin therapy, which inhibits vitamin K-dependent blood-clotting, has been demonstrated to reduce the risk of stroke in nonrheumatic atrial fibrillation. We evaluated vitamin K and bone mineral density in nonrheumatic atrial fibrillation patients who had long-term warfarin therapy after an ischemic stroke.

METHODS

Sera were collected from 64 patients with non-rheumatic atrial fibrillation and ischemic stroke who had been treated with warfarin, 63 stroke patients without warfarin, and 39 control subjects. All stroke patients in both groups had hemiplegia. Sera were assayed for vitamins K1 and K2, bone Gla protein, and 25-hydroxyvitamin D. Bone mineral density was determined in both second metacarpals.

RESULTS

Serum vitamin K1 concentrations (ng/mL) were lower in treated patients (.234 +/- .177 ng/mL) than in untreated patients (.329 +/- .284) or controls (.553 +/- .164). Bone Gla protein was lower in treated patients' sera (1.241 +/- .799 ng/mL) than in untreated patients (4.476 +/- 3.226). Concentrations of 25-hydroxyvitamin D were lower in both patient groups. Bone mineral density was lower on both sides in treated patients than in untreated patients (P < .0001). Vitamin K1 and bone Gla protein were significantly related to bone mineral density bilaterally in treated but not in untreated patients.

CONCLUSIONS

Bone mineral density was significantly lower in stroke patients with long-term warfarin treatment than in untreated patients. Both warfarin-induced reduction in vitamin K function and lowered vitamin K1 concentrations are probable causes of this osteopenia.

Modulation of arterial thrombosis tendency in rats by vitamin K and its side chains

Vitamin K is involved in the biosynthesis of a number of blood coagulation factors and bone proteins. It has been suggested that the vitamin K requirement of bone tissue is higher than that of the liver. Here we report that in rats very high doses of vitamin K affected neither the blood coagulation characteristics nor the blood platelet aggregation rate. This was observed for both phylloquinone and menaquinone-4. Both vitamers were also tested for their effects on the arterial thrombosis tendency in the rat aorta loop model. The mean obstruction times were prolonged at a high intake of menaquinone-4 (250 mg/kg body weight/day), and shortened after a similarly high phylloquinone regimen. Since (a) both vitamers only differ in their aliphatic side chains; and (b) a similar trend was observed after administration of phytol and geranylgeraniol, we conclude that the modulation of the arterial thrombosis tendency is accomplished by the side chain of vitamin K.

Plasma vitamin K1 and PIVKA-II after oral administration of mixed-micellar or cremophor EL-solubilized preparations of vitamin K1 to normal breast-fed newborns

BACKGROUND

Vitamin K1 prophylaxis in neonates is required for prevention of vitamin K1 deficiency bleeding. Although intramuscular administration of vitamin K1 is safe, this invasive method is not generally accepted. We therefore examined the pharmacokinetics of two orally administered vitamin K1 preparations in normal, fully breast-fed newborns.

METHODS

Within 1 hour of birth, each baby was randomized to a 2 mg dose of either a conventional Cremophor EL-solubilized preparation of vitamin K1 (Konakion drops, F. Hoffmann-La Roche, n = 16), or a new mixed-micellar preparation of vitamin K1 (Konakion MM, F. Hoffmann-La Roche, n = 14). The concentrations of vitamin K1, des-gamma-carboxyprothrombin (PIVKA-II), and total bound bilirubin were measured in plasma samples taken at 24 hours, 4 days, and 24 days after birth.

RESULTS

The median concentration of plasma vitamin K1 was higher at all three time points in the group that received the mixed-micellar preparation, but the difference was only significant (p < 0.05) at 4 days. At 24 hours and 4 days, PIVKA-II was detectable in a significantly lower proportions of infants receiving the new mixed-micellar preparation than those receiving the Cremophor EL preparation (21% vs. 75% at 24 hours, p < 0.05 and 14% vs. 50% at 4 days, p < 0.05). None of the infants in the study had detectable PIVKA-II levels 24 days after birth.

CONCLUSIONS

Our results suggest that when given orally, the mixed-micellar preparation is superior to the conventional formulation because it increases plasma vitamin K1 concentrations to higher levels, suggesting superior bioavailability, and decreases PIVKA-II concentrations more efficiently, suggesting a faster pharmacodynamic response.

Nutritional vitamin K-intake and urinary gamma-carboxyglutamate excretion in the rat

Using the rat as an experimental animal model we have found that prothrombin synthesis reaches its maximal level at a relatively low dietary vitamin K intake. At still higher vitamin K intakes, however, the urinary Gla-excretion was substantially increased, showing a different vitamin K requirement for liver and extrahepatic tissues. The increased urinary Gla-excretion was found for both phylloquinone and menaquinone-4, but not for menaquinone-8, which questions the bioavailability of higher menaquinones for extrahepatic tissues. A discrepancy was found between effects of nutritional vitamin K-deficiency and treatment with a vitamin K-antagonist (brodifacoum). With both regimens plasma prothrombin rapidly decreased to well below 10% of the starting values, but in case of K-deficiency urinary Gla had hardly decreased in 7 days, whereas after 3 days of brodifacoum treatment Gla-excretion had decreased to 17% of the starting values. An explanation for this observation is that prothrombin procoagulant activity does not decrease proportional to the prothrombin Gla-content, but that a wide range of undercarboxylated prothrombins have lost nearly all activity. During vitamin K-deficiency the remaining low levels of vitamin K would mainly give rise to undercarboxylated prothrombin, whereas during brodifacoum treatment only non-carboxylated prothrombin is formed. It seems plausible that in the latter case the urinary Gla originates from proteins with long half-life times, such as the bone Gla-proteins.

Fatal cerebellar haemorrhage due to phenprocoumon poisoning

A 32-year-old patient died of a cerebellar haemorrhage and the blood coagulation analysis before death suggested defective synthesis of vitamin K-dependent clotting factors due to vitamin K deficiency. The post-mortem toxicological examination of different tissues revealed phenprocoumon poisoning as the cause of death. The differential diagnosis of vitamin K deficiency and the toxicology of hydroxycoumarins are discussed.

Dihydro-vitamin K1: primary food sources and estimated dietary intakes in the American diet

Dihydro-vitamin K1 was recently identified as a dietary form of vitamin K produced during the hydrogenation of vitamin K1-rich vegetable oils. Dihydro-vitamin K1 is absorbed, with measurable levels in human plasma following dietary intake. To determine the primary food sources of dihydro-vitamin K1 in the American diet, 261 foods from the U.S. Food and Drug Administration's (FDA) Total Diet Study (TDS) were analyzed by high-performance liquid chromatography. Of these foods, 36 contained dihydro-vitamin K1. Fast-food items that were otherwise poor sources of vitamin K1, such as french fries and fried chicken, contained appreciable amounts of dihydro-vitamin K1 (36 and 18 micrograms/100 g, respectively). These nutrient values were then applied to the FDA TDS consumption model to determine average dietary intake of dihydro-vitamin K1 in 14 age-gender groups. With the exception of infants, all age-gender groups had estimated mean daily dihydro-vitamin K1 intakes of 12-24 micrograms, compared to mean daily vitamin K1 intakes of 24-86 micrograms. The vitamin K1 and dihydro-vitamin K1 intakes were summed, and the dietary contribution of dihydro-vitamin K1 was expressed as a percentage of total vitamin K intake. Children reported the highest intakes of dihydro-vitamin K1 (30% of total vitamin K intake), followed by a progressive decrease in percentage contribution with age. There are currently no data on the relative bioavailability of dihydro-vitamin K1 but given its abundance in the American diet, this hydrogenated form of vitamin K warrants further investigation.

Food sources and dietary intakes of vitamin K-1 (phylloquinone) in the American diet: data from the FDA Total Diet Study

OBJECTIVE

To identify important food sources and estimate dietary intake of vitamin K-1 (phylloquinone) in the American diet.

DESIGN

Core foods from the US Food and Drug Administration (FDA) Total Diet Study (TDS), which was based on the 1987-88 Nationwide Food Consumption Survey (NFCS), were analyzed for vitamin K-1. These nutrient values were then applied to the FDA TDS consumption model.

SUBJECTS

Of the NFCS participants within the 14 selected age-gender groups, 3,634 who had 3 days of dietary data were included in the FDA TDS consumption model.

MAIN OUTCOME MEASURES

Vitamin K-1 intakes were estimated for each of the age-gender groups; the percentage contribution of each food item to total intake of vitamin K-1 was calculated from the FDA TDS model.

RESULTS

Of the 14 age-gender groups selected, the 25- to 30-year-old women and men consumed less than the current Recommended Dietary Allowance (RDA) for vitamin K. In contrast, formula-fed infants had estimated vitamin K-1 intakes six times greater than the RDA. All other groups consumed amounts within the recommended daily intakes but lower than 90 micrograms/day. The top contributors to total vitamin K-1 intake were dark-green vegetables, although the fats and oils added to mixed dishes and desserts were also important contributors. The proportion of vitamin K-1 obtained from vegetables increased with age.

APPLICATIONS

The data identify important dietary sources of vitamin K-1 in the American diet. This knowledge can be used to develop dietary assessment instruments for use in epidemiologic studies.

Carboxylation of osteocalcin in post-menopausal osteoporotic women following vitamin K and D supplementation

The effect of vitamin supplements on bone metabolism indices in patients with osteoporosis has received scant attention in the literature. Over a 2-week period, vitamin supplements of K and K+D were given to 20 post-menopausal osteoporotic women with previous Colles fractures. Osteoporosis was confirmed by bone mass measurements that demonstrated that broadband ultrasound attenuation (os calcis) was almost as discriminatory as dual energy X-ray absorptiometry (spine and hip) in Colles fracture patients compared with matched controls. Vitamin K corrected the carboxylation defect in osteocalcin and while less marked 4 weeks later, the improvement was still detectable. The result after K+D was similar. The level of carboxylation became the same as in premenopausal women. Total osteocalcin level (bound) osteocalcin. While there was vitamin K correctable undercarboxylation of osteocalcin, simultaneously there was no evidence of undercarboxylation of prothrombin.