Effects of topical vitamin K and retinol on laser-induced purpura on nonlesional skin

BACKGROUND

Pulsed dye laser treatments usually result in purpura. Any topical application that eliminates or shortens the duration of purpura would be extremely useful.

OBJECTIVE

The purpose of this prospective study was to determine the safety and efficacy of topical vitamin K cream in shortening the duration of laser-induced purpura.

METHODS

Twenty adult subjects were enrolled. Each subject had five 1.5 cm sites treated with a pulsed dye laser at 585 nm, 450 nsec, 7 mm spot size at each subject's respective threshold fluence. Each subject had a control site where no topical application was used and four other sites where a different formulation was applied to each for 2 weeks before and for 2 weeks after laser irradiation. Five vitamin K formulations with or without retinol were studied: 3% vitamin K in acrylates copolymer cream, 5% vitamin K in acrylates copolymer cream, 1% vitamin K and 0.3% retinol in acrylates copolymer cream, 1% vitamin K and 0.15% retinol in acrylates copolymer cream, 1% free vitamin K cream. Purpuric discoloration at each site was rated on days 0, 1, 3, 7, 10, and 14 after laser treatment on a quartile scale. Each site was assigned 100% discoloration on day 0 after laser irradiation.

RESULTS

Laser-induced purpuric discoloration resolved faster with 1% vitamin K and 0.3% retinol in acrylates copolymer cream than with no topical application. The difference is statistically significant from day 3 onward.

CONCLUSION

A combination of 1% vitamin K and 0.3% retinol in acrylates copolymer cream hastened the resolution of laser-induced purpura.

Absorption of vitamin K2 by dogs after oral administration of a soft gelatin capsule formulation containing a new emulsion-type vehicle

This study has evaluated the performance of a newly developed vehicle for administration of a drug in a soft gelatin capsule. The absorption of vitamin K2 in dogs after oral administration of the vitamin in a soft gelatin capsule containing the newly developed vehicle was compared with absorption after administration of a control formulation prepared by encapsulating the contents of a commercially available vitamin K2 capsule (Glakay capsules 15 mg) in the same type of soft gelatin. Under non-fasted conditions the profile of the plasma concentration of vitamin K2 against time for the test formulation was comparable with that for the control formulation in non-fasted dogs. Under fasted conditions, however, both the maximum concentration (Cmax) and the area under the plot of concentration against time (AUC) were significantly smaller for the test formulation than for the control formulation. The Cmax and AUC for the test formulation were about 10 times larger for non-fasted dogs than for fasted dogs whereas values for the control formulation were about twice as large. These results suggest that both formulations might require the presence of food or digestive fluid components, or both, for better absorption of vitamin K2. It seems that although the performances of the test and control formulations were comparable in the presence of these components, the control formulation works better in their absence. It should be also noted that, in contrast with the results from the absorption tests, the dispersibility of the test vehicle in water was much better than that of the control vehicle. This suggests that dispersibility does not significantly affect vitamin K2 absorption. In conclusion, although the new vehicle did not perform better than the control vehicle in terms of vitamin K2 absorption, the performance of the control formulation was comparable for non-fasted dogs. Because the new vehicle contains considerably less surfactant than the vehicles currently used in soft gelatin capsules, it could be a safer alternative for use under non-fasted conditions.

Vitamin K to reverse excessive anticoagulation: a review of the literature

We conducted an extensive literature review to evaluate the appropriate use, route, and dose of vitamin K to reverse excessive anticoagulation. Issues such as sample size, study design, different patient populations, and various study end points confounded results. Of 18 studies published, 8 enrolled 229 patients to evaluate parenteral vitamin K administration. Nine studies with 288 patients evaluated oral administration, and only 2 retrospective studies (280 patients) compared routes of administration. Reductions in international normalized ratios at 24 hours ranged from 21-42%, 47-86%, 25-67%, and 40-75% for temporary warfarin discontinuation alone, and intravenous, subcutaneous, and oral routes of vitamin K administration, respectively. Methodologically weak studies and indeterminate results plague interpretation of the literature on vitamin K. In general, results of this review support current guidelines for reversing excessive warfarin anticoagulation. However, it is important to realize that the quality of literature on which these recommendations are based is poor and that optimal dose and route of vitamin K administration remain unclear. Large, well-designed, randomized, controlled trials are necessary to define optimum management strategies for excessively anticoagulated patients.

The effect of vitamin K and D supplementation on ovariectomy-induced bone loss

This study was designed to assess the effect of vitamin K and D supplementation on ovariectomy-induced bone loss. Female Sprague-Dawley rats aged 8-9 months were ovariectomized (OVX) or sham operated and divided into five experimental groups: (1) ovariectomy (OVX), (2) OVX plus vitamin K supplementation, (3) OVX plus vitamin D supplementation, (4) OVX plus vitamin K and vitamin D supplementation, and (5) sham operation. The trabecular bone area was estimated by bone histomorphometry by microradiography and histological examination. Bone loss in OVX plus vitamin K and vitamin D group was significantly reduced at both 7 and 14 weeks compared with the OVX group. No significant bone loss in OVX plus vitamin K or OVX plus vitamin D groups was found. A similar effect of vitamin K and D supplementation on ovariectomy-induced bone loss was recognized in histological examination. Our findings indicate that vitamins K and D may have a synergistic effect on reducing bone loss. This is valuable information for the treatment of bone loss in postmenopausal women with osteoporosis.

[Derailed oral anticoagulation with very high INR values and poor response to oral vitamin K--cholestasis as a possible cause]

A 76-year-old man under long term oral anticoagulant treatment showed unclottable prothrombin time (PT) without overt bleeding. After oral administration of vitamin K1, PT remained severely prolonged and the patient was hospitalized. INR was 8.0 and responded to parenteral vitamin K. Cholestasis resulting in poor intestinal vitamin K resorption was assumed to have caused "overanticoagulation". Quick test is a global clotting test for the extrinsic and common pathways of the coagulation system. Increased PT, i.e. decreased Quick percentage, may be due to different conditions and should--if unexplained--be further analyzed by assaying factors II, V, VII, X and fibrinogen. Preanalytical problems, plasma dilution with clotting factor-free volume replacement, decreased vitamin K-dependent clotting factors (oral anticoagulation, intoxication with certain rodenticides, vitamin K deficiency), impaired liver synthetic capacity, disseminated intravascular coagulation, or massive heparin contamination may cause prolonged PT. Newborns physiologically have longer PT and should receive vitamin K prophylaxis.

Vitamin K: a practical guide to the dietary management of patients on warfarin

Warfarin has been successfully used in the medical management of thromboembolic disease for nearly six decades. It is widely assumed that a dietary vitamin K-warfarin interaction exists. To avoid this potential interference with the efficacy of warfarin in stable anticoagulation, patients typically receive instructions to consume a constant dietary intake of vitamin K. While dark, green vegetables are primary sources of dietary vitamin K, these foods are not commonly consumed on a daily basis in the United States. However, there still exists dietary resistance to warfarin that is attributable to vitamin K. Based on food analysis studies on vitamin K, it is now known that dietary vitamin K is found in certain plant oils and prepared foods containing these plant oils, such as baked goods, margarines, and salad dressings. The preparation of foods with vitamin K-rich oils may also contribute to a diet-warfarin interaction, although this has yet to be confirmed in a clinical trial. A dose-response of vitamin K on the effect of warfarin anticoagulation has not yet been established. However, there are sufficient data to suggest that a constant dietary intake of vitamin K that meets current dietary recommendations of 65-80 micrograms/day is the most acceptable practice for patients on warfarin therapy. Vitamin K composition data for commonly consumed foods are now available and may facilitate successful anticoagulation for patients being treated with warfarin.

Use of vitamin K2 (menatetrenone) and 1,25-dihydroxyvitamin D3 in the prevention of bone loss induced by leuprolide

The purpose of this study is to evaluate the efficacy of vitamin K2 and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in preventing bone loss induced by estrogen deficiency during therapy with the GnRH agonist (GnRH-a) leuprolide. One hundred ten women (mean age, 46.2+/-0.5 yr), receiving leuprolide therapy for estrogen-dependent diseases (such as endometriosis and uterine leiomyomas), were randomly allocated into four groups (group A, leuprolide only; group B, leuprolide with vitamin K2; group C, leuprolide with 1,25-(OH)2D3; and group D, leuprolide with vitamin K2 and 1,25-(OH)2D3). Bone mineral density of the lumbar spine was measured by dual-energy x-ray absorptiometry before and after 6 months of treatment. Bone formation and resorption markers were also measured before and after 6 months of treatment. There were no significant differences in the background parameters among the four groups. Bone mineral density was reduced in all four groups, but the percent changes varied slightly, at - 5.25% (group A), -3.72% (P < 0.05 vs. group A) (group B), -4.13% (group C), and -3.59% (P < 0.01 vs. group A) (group D), respectively. Bone formation markers were significantly increased in all four groups, and the percent changes of bone formation markers were highest in group B. Bone resorption markers also increased significantly in all four groups after treatment of 6 months. Group B tended to have the highest percent changes of bone resorption markers among the four groups, but these increases were not significantly different between any of the groups. Vitamin K2, especially when combined with 1,25-(OH)2D3, can partially prevent bone loss caused by estrogen deficiency. However, because this effect is attributable mainly to the activation of bone formation, it is not sufficient to eliminate bone loss induced by GnRH-a therapy.

Vitamin K status of lactating mothers and their infants

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

Intracranial hemorrhage in an infant owing to vitamin K deficiency despite prophylaxis

A 3-month-old male infant with intracranial hemorrhage attributable to a vitamin K deficiency is reported. Vitamin K2 was administered orally at birth and then at 5 days and I month of age. Oral antibiotics were also given 2 days before the onset of bleeding. Although the incidence of intracranial hemorrhage resulting from vitamin K deficiency has decreased since the introduction of vitamin K2 prophylaxis, spontaneous intracranial hemorrhages are still being reported in infants. We suggest that vitamin K prophylaxis is needed especially for breast-fed infants and for those undergoing antibiotic therapy.

Does perinatal phenobarbital exposure affect developmental outcome at age 2?

The objective of this paper is to determine if phenobarbital exposure during pregnancy affects developmental outcome at age 2 years. Between 1991 and 1994, 401 pregnant patients at risk for delivery prior to 34 weeks' gestation were invited to participate; 48 mothers declined entry. Before delivery, pharmacy randomized the pregnant women to receive phenobarbital and vitamin K or identically appearing placebo in a blinded fashion. Developmental follow-up at age 2 years was performed. Children from the treatment group scored significantly lower on the Bayley Mental Developmental Index (mean MDI +/- 1 SD) than children whose mothers were randomized to the placebo group [104 +/- 21 (n = 59) vs. 113 +/- 22 (n = 62), p = 0.023]. Of 36 independent variables, randomization group was one of five that individually contributed to the prediction of the Bayley MDI score (p < 0.05). It was concluded that perinatal phenobarbital therapy may impair developmental outcome.

Vitamin K reduces bleeding in left ventricular assist device recipients

BACKGROUND

Despite advances in left ventricular assist device (LVAD) design that permit support without anticoagulation, LVAD recipients often suffer profound bleeding complications. This bleeding diathesis may be attributable to pre-operative right-ventricular failure with concomitant hepatic dysfunction. The purpose of this study was to characterize coagulation abnormalities in LVAD recipients and determine the impact of pre-operative vitamin K administration on the incidence of postoperative bleeding.

METHODS

Hemostatic and liver function profiles were obtained in 66 recipients of the Heartmate LVAD; 39 of these patients received perioperative vitamin K.

RESULTS

During LVAD support, hepatic synthetic function improved as evidenced by increases in clotting factors II, V, VII, XI. There was ongoing fibrinolysis with elevation of fibrinopeptide A and D-dimers and diminution of fibrinogen; however, plasminogen levels did not decline suggesting that systemic disseminated intravascular coagulation (DIC) did not occur. Bleeding requiring re-exploration more than 48 hours postimplantation occurred in 9 of 66 patients (13.6%). Prior to implantation, patients that bled had decreased levels of factor II (52.2 +/- 27.1% vs 69.7 +/- 26.6%; p = 0.048) and prolonged prothrombin times (16.5 +/- 2.4 seconds vs 13.8 +/- 3.1 seconds; p = 0.005) compared to patients that did not bleed. Seven of 27 patients (25.9%) not treated with vitamin K bled, while only 2 of 39 (5.1%) patients treated with vitamin K required re-exploration for bleeding (p = 0.026).

CONCLUSIONS

We conclude that: (1) Liver synthetic function improves during LVAD support resulting in increased levels of circulating coagulation factors; (2) ongoing fibrinolysis occurs but likely only represents remodeling of fibrin on the LVAD surface; (3) perioperative vitamin K reduces nonsurgical bleeding in LVAD recipients.

Prevention of vitamin K deficiency bleeding in newborns

Newborn babies are born vitamin K deficient; however, the deficiency is not sufficiently severe to cause a vitamin K deficiency coagulopathy and haemorrhagic disease of the newborn (HDN). Severe vitamin K deficiency can develop quickly in breast-fed newborns and can result in the appearance of classic HDN during the first week of life or late HDN during the first 2 months of life. Both forms of the disease can be severe, causing brain damage and death. Classic and late HDN are prevented by the intramuscular administration of vitamin K at birth. Oral prophylaxis prevents classic HDN but is ineffective in preventing late HDN. Despite proven effectiveness of intramuscular vitamin K prophylaxis there have been concerns about the need for, and safety of, this therapy. This review provides evidence that there is need for intramuscular vitamin K prophylaxis for all babies in order to eradicate haemorrhagic disease of the newborn and concludes that there is no evidence that this therapy is harmful.

Vitamin K intake and sensitivity to warfarin in patients consuming regular diets

The effect of dietary vitamin K intake on warfarin sensitivity is known only from case reports and few small clinical studies. We followed 50 patients commencing warfarin and consuming their regular diets (for 8 weeks) to study this relationship. A one-week recall dietary questionnaire was completed at weeks 2 and 8. Daily intake of nutrients and vitamin K was calculated from standard tables. Warfarin sensitivity index (WSI) was defined as final INR/final warfarin dose (mg/day/m2 of body surface area) (week 8). Vitamin K intake was 17-974 (median: 179) microg/day. Median WSI was 0.82 (0.31-4.47). A WSI value of 1.1 significantly separated excess (>250 microg/day) from normal (<250 microg/day) vitamin K consumers (16/18 vs. 15/32, respectively, p <0.01). The former had lower day 5 INR (median: 1.9 vs. 3.0, p <0.001), needed more warfarin to achieve INR > or =2.0 (32.0+/-9.2 mg vs. 25.4+/-6.4 mg, p = 0.009) and required a higher maintenance steady state warfarin dose (5.7+/-1.7 mg/day vs. 3.5+/-1.0 mg/day, p <0.001). We conclude that in 32% (16/50) of anticoagulated patients under usual dietary conditions sensitivity to warfarin is decreased by vitamin K intake > or =250 microg/day.

[Interaction of warfarin and vitamin K2 on arterial thrombotic tendency using a rat aorta loop model]

Vitamin K2(K2), a therapeutic agent osteoporosis, is prohibited for patients with thrombosis who are receiving warfarin (WF). However, because some aged patients with thrombosis have osteoporosis, some patients treated with WF may be administered K2 concomitantly. We investigated here the interaction between K2 and WF on thrombosis in a rat aorta loop model. Administration of WF at 0.58, 0.82 and 1.16 mg/l in drinking water for 7 days decreased the thrombotic rate and increased the death rate, dose-dependently. Therefore in the following study, 0.80 mg/l of WF was used. After 2 days of WF-treatment, 1.5, 14 and 145 mg/kg of K2 was administered for 5 days. The blood coagulation time was markedly prolonged by WF treatment for 7 days and this effect was completely inhibited by all doses of K2. WF treatment significantly decreased the cumulative thrombotic rate for 5 days. Administration of 1.5 and 14 mg/kg of K2 did not influence the WF effect on thrombosis. The thrombotic rate in the 145 mg/kg K2 group was lower than that in the WF-control group, but similar to that in the WF-untreated group. These findings suggest that high dose of K2 reduces the effect of WF on thrombosis but does not enhance the occurrence of thrombosis more than that without WF treatment.

Relationship between acute insulin response and vitamin K intake in healthy young male volunteers

To evaluate the effects of vitamin K (VK) on pancreatic function, especially on acute insulin response, 25 healthy young male volunteers were given an oral load of 75 g of glucose, and their mean daily VK intake was estimated by a one-week food check list. After excluding low (<20) and high (> or =25) body mass index (BMI) subjects, the remaining 16 participants were divided into three semi-equal groups according to VK intake. Blood VK status of the low VK intake group tended to be poorer than that of the high intake group (median of 5 samples: prothrombin time; 12.5 vs 12.2s and protein-induced VK absence-factor-II; 23 vs 15 mAU/ml), but fasting plasma glucose status was not markedly different between both groups: [plasma glucose (PG); 87 vs 86 mg/dl, immunoreactive insulin (IRI); 6.7 vs 5.3 microU/ml, HbA1c; 4.8 vs 4.9%]. However, at 30 min after glucose loading, PG of the low VK intake group tended to be higher than those of the high intake group (160 vs 145 mg/dl) and IRI was lower (36.1 vs 52.3 microU/ml). Insulinogenic index (incremental IRI/incremental PG, 0-30 min) of the low VK intake group was significantly lower than that of the high intake group (0.4 vs 0.9). These results suggested that VK may play an important role on the acute insulin response in glucose tolerance.

Obstetric and gynecologic care of women with epilepsy

Optimal gynecologic and obstetric care for women with epilepsy requires a multidisciplinary approach throughout the various life stages. Epilepsy has important effects on puberty, contraceptive efficacy, pregnancy and fetal development, and menopause. This article discusses these effects and makes recommendations for gynecologic and obstetric care of patients with epilepsy, with particular focus on pregnancy. Despite very real risks to both the developing fetus and the mother, the majority of women with epilepsy--with appropriate pregnancy planning and management--have good pregnancy outcomes.

[Drug use in a neonatal unit]

All medication administered to patients admitted to a neonatal intensive care unit was registered during a one-year period (1996). Only two (0.4%) of 469 infants admitted were not given any drug at all. A total of 12,019 single doses were administered, a mean of 33 per day. 7,042 (59%) were given orally, and 3,332 (28%) intravenously. 292 (63%) patients were given vitamin K as the only drug. 113 infants (24%) received systemic antibiotic treatment, 5% of all infants born alive at the hospital. Drugs accounted for 2.7% of the total expenses for running the unit. Surfactant (12 single doses) alone accounted for 47% of the costs of drugs. Drug monitoring by serum concentration measurements showed that 32% of the values were outside the therapeutic range. To a limited extent (44%) this was followed by correction of the dose. One single drug dose (1 per 10,000 doses) was administered to a patient for whom the drug was not prescribed. Quality assurance of medication is an important task in neonatal intensive care units.

O/W lipid emulsions for parenteral drug delivery. IV. Changes in the pharmacokinetics and pharmacodynamics of a highly lipophilic drug, menatetrenone

The pharmacokinetics and pharmacodynamics of antihemorrhagic vitamin, menatetrenone after intravenous injection as the lipid emulsion, were compared to those as the micellar solutions. Menatetrenone was selectively delivered to the liver, lungs and spleen and retained in them. Hepatic and splenetic concentration at 6 h (C6h) increased 21.6- and 27.1-fold, respectively, and the area under the tissue concentration-time curve up to 6 h (AUC(0-6h)) were 2.3- and 11.4-fold, respectively, when compared with its micellar solution. Antihemorrhagic effect of menatetrenone was assessed using warfarin-induced hypoprothrombinemic rats. The lipid emulsion of menatetrenone decreased the prothrombin time at 6h after intravenous injection more effectively than micellar solution. The dose response curves indicated that the efficacy of the lipid emulsion was 2.4-2.9 times that of a micellar solution, and this was correlated with AUC(0-6h) rather than C6h. The plasma level of clotting factor VII and the hepatic level of descarboxyprothrombin were also recovered more effectively, while no significant differences were noted between the two formulations for the plasma level of factor II or descarboxyprothrombin at the dose levels examined. Although selective delivery of menatetrenone in the liver by the lipid emulsion was due to phagocytosis by non-parenchymal cells, menatetrenone in the whole liver appeared to contribute to recovery from hypoprothrombinemia.

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.

Effect of vitamin K2 (menaquinone-7) in fermented soybean (natto) on bone loss in ovariectomized rats

The effect of dietary vitamin K2 (menaquinone-7) on bone loss in ovariectomized (OVX) rats was investigated. OVX rats were freely given experimental diets containing menaquinone-4 (MK-4; 12mg/100g diet) or menaquinone-7 (MK-7; 18.1mg/100g diet) for 24 days; MK-4 and MK-7 were equal in molar concentrations. This feeding caused a remarkable increase of MK-4 and MK-7 concentrations in the serum and femur of OVX rats. OVX-induced decrease in the femoral dry weight and femoral calcium content was prevented by the feeding of dietary MK-4 or NK-7. In separate experiments, OVX rats were freely given experimental diets containing the fermented soybean (natto; including 9.4 microg MK-7/100g diet) without or with added MK-7 (37.6 microg/100g diet) for 77 days. Feeding produced a significant elevation of MK-4 and MK-7 concentrations in the serum of OVX rats. In this case, a significant increase in the femoral MK-4 content was observed but MK-7 was not detected in the femoral tissues. OVX-induced decreases in the femoral dry weight and femoral calcium content were significantly prevented by the feeding of diets containing natto with MK-7 added (37.6 microg/100g diets). This study demonstrates that the intake of dietary MK-7 has a preventive effect on bone loss caused by OVX. This effect may be partly caused by MK-4, which is formed by degradation of MK-7.

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.