Vitamin K1 Levels Research Articles

Vitamin K2 Deficiency and its Association with Short Stature in Children: A Cross-Sectional Study

ObjectivesThis study examines the relationship between vitamin K2 (VK2) status and the occurrence of short stature in children. MethodsA cross-sectional analysis was conducted between January 2021 and August 2022, involving 235 children with a clinical diagnosis of short stature at the Second Affiliated Hospital of Wenzhou Medical University (short stature group) and 454 children with average height (±1 SD) from the same period (healthy group). Serum VK2 levels were compared between the two groups. Multivariate logistic regression analysis was used to identify factors associated with short stature, and Spearman correlation analysis was used to examine the relationship between VK2 status and age. ResultsChildren in the short stature group exhibited lower VK2 levels (P = 0.019) and a significantly higher prevalence of VK2 deficiency (P = 0.011) compared to the healthy group. VK2 deficiency was identified as an independent risk factor for short stature (OR = 1.535, 95% CI = 1.061–2.222, P = 0.023) through multivariate logistic regression analysis. Furthermore, an inverse correlation was observed between serum VK2 levels and age in children aged 2 to 15 years (ρ = -0.133, P < 0.001). ConclusionsVK2 deficiency may be associated with an increased risk of short stature in children.

An analysis of vitamin K status in Chinese healthy children aged 0–18 years

BackgroundVitamin K (VK), an essential fat-soluble nutrient, exists in two primary forms, vitamin K1 (VK1), and vitamin K2 (VK2). VK1 plays an essential role in blood coagulation, while VK2 plays a crucial role in managing bone calcification, supporting bone strength and health. However, comprehensive epidemiological data on VK remains sparse, particularly in children. This study aims to evaluate the levels and characteristics of VK in children of Wenzhou area, China.MethodsA total of 3,342 children undergoing routine physical examinations in the outpatient department from December 2020 to August 2022 were recruited. The levels of VK (including VK1 and menaquinones (MK-4), a major form of VK2) and 25-hydroxy vitamin D (25(OH)D) in fasting serum samples from these children were measured using high-performance liquid chromatography-tandem mass spectrometry. The study analyzed the levels and distribution of VK and 25(OH)D across different sex, age, and weight groups, and explored their potential related factors.ResultsThe median serum levels of MK-4 and VK1 were 0.12 (0.07, 0.21) ng/ml and 0.33 (0.18, 0.57) ng/ml, respectively. The reference ranges of MK-4 and VK1 were 0.01–0.58 ng/ml and 0.03–1.48 ng/ml, respectively. The median serum 25(OH)D level was 21.26 (17.30, 25.35) ng/ml. Moreover, there were no significant variations in the levels of MK-4 and VK1 across different age and sex groups. The level of MK-4 in the underweight group was significantly higher than that in the normal weight group. MK-4 level reached its peak in summer, while the VK1 concentration was at its lowest. Furthermore, a very weak positive correlation was revealed between MK-4 and VK1 levels.ConclusionIn this study, we defined the median values and reference ranges of MK-4 and VK1 in a sample of Chinese children aged 0–18 years. MK-4 levels were higher in underweight children. Both MK-4 and VK1 levels exhibited seasonal variations. Further research is needed to explore the factors affecting MK-4 and VK1 levels.

Circulating Phylloquinone and the Risk of Four Female-Specific Cancers: A Mendelian Randomization Study.

Observational studies have linked vitamin K and cancer, but the causality of this association remains unknown. This Mendelian randomization (MR) study aims to investigate the association between circulating phylloquinone (vitamin K1) levels and four female-specific cancers. We used four single-nucleotide polymorphisms (SNPs) to instrument phylloquinone, with the reported F-statistic 16.00-28.44 for all variants. SNP-outcome associations were obtained from consortia meta-analyses, UK Biobank, and the FinnGen database (up to 145,257/419,675, 27,446/362,324, 15,181/591,477, and 2211/320,454 cases/controls for breast, ovarian, endometrial, and cervical cancer, respectively). Analyses were conducted using five complementary MR methods including pleiotropy robust approaches. The MR Egger intercept test, MR PRESSO global test and leave-one-out analyses were used to test for and identify pleiotropic variants. The relevance of the instrument was validated by positive control analyses on coagulation factor IX (p = 0.01). However, the main MR analysis and all sensitivity analyses were consistently supportive of a null association between phylloquinone and all four cancers (p > 0.05 for all analyses, across all methods). MR-PRESSO did not detect outlying variants, and there was no evidence of horizontal pleiotropy relating to any cancer outcome (pintercept > 0.26 for all). We found no evidence for an association between genetically predicted circulating phylloquinone levels and the risk of four female-specific cancers.

6683 The Interrelationship of Baseline Vitamin K and Vitamin D Status on Incident Fractures: Results from the VITamin D and OmegA-3 TriaL (VITAL)

Abstract Disclosure: S.H. Chou: None. S.L. Booth: None. D. Ratnarajah: None. N. Cook: None. G. Kotler: None. X. Fu: None. J. Buring: None. J.E. Manson: None. M.S. LeBoff: None. Vitamin D and vitamin K have interdependent roles in bone metabolism. We recently reported that, in the VITamin D and OmegA-3 TriaL (VITAL), daily supplemental vitamin D (2000 IU/d) vs. placebo did not reduce fracture risk in 25,871 U.S. men (aged ≥50) and women (aged ≥55).[1] While vitamin D stimulates transcription and translation of osteocalcin (OC) and matrix Gla protein (MGP), vitamin K is needed to carboxylate and activate these proteins. Older adults tend to have low vitamin K intakes, and low vitamin K status may attenuate effects of vitamin D on bone. In this VITAL ancillary study, we tested in a case-cohort sample of 1,162 participants with fractures and an age-sex-matched subcohort size of 2,652, whether baseline low vitamin K status, alone or in combination with lower 25(OH) vitamin D level, predicts incident total, non-vertebral, and hip fractures. The mean (±SD) age of participants was 68.3±7.2 years, 61.5% were female, and 81.7% was Non-Hispanic White. Fractures were reported on annual questionnaires and adjudicated through medical record review. To assess vitamin K function, percent undercarboxylated OC (%ucOC) and dephosphorylated undercarboxylated MGP ([dp]ucMGP) were measured in fasting baseline blood samples, with %ucOC calculated from measures of ucOC and total OC. Higher levels of %ucOC and (dp)ucMGP indicate lower vitamin K status. Serum 25(OH)D was measured by LC-MS/MS and vitamin K biomarkers by sandwich ELISAs (IDS-iSYS Multi-Discipline Automated System). Participants with incident fracture had higher baseline vitamin K status, as assessed by (dp)ucMGP levels, but this was not corroborated by %ucOC. Compared to participants with low baseline vitamin K status and baseline 25(OH) vitamin D levels below the median (30.0 ng/mL), participants with higher baseline vitamin K and D status had a similar incidence of total and non-vertebral fractures. For the 91 hip fracture cases, baseline status of vitamin K and D did not predict hip fracture incidence. In this ancillary study, low vitamin K status by (dp)ucMGP and %ucOC, alone or in combination with baseline 25(OH) vitamin D levels below the median, was not associated with increased fracture incidence. Ongoing analyses are assessing whether phylloquinone levels as another vitamin K biomarker predict incident fracture risk. Furthermore, we have also previously shown that the effects of supplemental vitamin D on total and hip fractures were not modified by baseline vitamin K status in VITAL, the largest randomized controlled trial of supplemental vitamin D vs. placebo on fractures. From our findings in VITAL, higher vitamin K status does not protect against fractures. 1. LeBoff MS, et al. NEJM. 2022. Presentation: 6/1/2024

9275 The Interrelationship of Baseline Vitamin K and Vitamin D Status on Incident Fractures: Results from the VITamin D and OmegA-3 TriaL (VITAL)

Abstract Disclosure: S.H. Chou: None. S.L. Booth: None. D. Ratnarajah: None. N. Cook: None. G. Kotler: None. X. Fu: None. J. Buring: None. J.E. Manson: None. M.S. LeBoff: None. Vitamin D and vitamin K have interdependent roles in bone metabolism. We recently reported that, in the VITamin D and OmegA-3 TriaL (VITAL), daily supplemental vitamin D (2000 IU/d) vs. placebo did not reduce fracture risk in 25,871 U.S. men (aged ≥50) and women (aged ≥55).[1] While vitamin D stimulates transcription and translation of osteocalcin (OC) and matrix Gla protein (MGP), vitamin K is needed to carboxylate and activate these proteins. Older adults tend to have low vitamin K intakes, and low vitamin K status may attenuate effects of vitamin D on bone. In this VITAL ancillary study, we tested in a case-cohort sample of 1,162 participants with fractures and an age-sex-matched subcohort size of 2,652, whether baseline low vitamin K status, alone or in combination with lower 25(OH) vitamin D level, predicts incident total, non-vertebral, and hip fractures. The mean (±SD) age of participants was 68.3±7.2 years, 61.5% were female, and 81.7% was Non-Hispanic White. Fractures were reported on annual questionnaires and adjudicated through medical record review. To assess vitamin K function, percent undercarboxylated OC (%ucOC) and dephosphorylated undercarboxylated MGP ([dp]ucMGP) were measured in fasting baseline blood samples, with %ucOC calculated from measures of ucOC and total OC. Higher levels of %ucOC and (dp)ucMGP indicate lower vitamin K status. Serum 25(OH)D was measured by LC-MS/MS and vitamin K biomarkers by sandwich ELISAs (IDS-iSYS Multi-Discipline Automated System). Participants with incident fracture had higher baseline vitamin K status, as assessed by (dp)ucMGP levels, but this was not corroborated by %ucOC. Compared to participants with low baseline vitamin K status and baseline 25(OH) vitamin D levels below the median (30.0 ng/mL), participants with higher baseline vitamin K and D status had a similar incidence of total and non-vertebral fractures. For the 91 hip fracture cases, baseline status of vitamin K and D did not predict hip fracture incidence. In this ancillary study, low vitamin K status by (dp)ucMGP and %ucOC, alone or in combination with baseline 25(OH) vitamin D levels below the median, was not associated with increased fracture incidence. Ongoing analyses are assessing whether phylloquinone levels as another vitamin K biomarker predict incident fracture risk. Furthermore, we have also previously shown that the effects of supplemental vitamin D on total and hip fractures were not modified by baseline vitamin K status in VITAL, the largest randomized controlled trial of supplemental vitamin D vs. placebo on fractures. From our findings in VITAL, higher vitamin K status does not protect against fractures. 1. LeBoff MS, et al. NEJM. 2022. Presentation: 6/1/2024

Study on Vitamin K Levels in Mature Milk of Chinese Lactating Mothers.

This study sought to understand the levels of vitamin K in the mature milk of Chinese lactating mothers, thereby providing a foundation for the development of appropriate intake (AI) of vitamin K for infants aged 0-5 months. Five hundred healthy lactating mothers were selected from the mature milk bank established by the Chinese Maternal and Infant Nutrition and Health Cohort by using a simple random sample procedure. Relevant information about lactating mothers and their infants was obtained by a questionnaire survey. Vitamin K1 and vitamin K2 (MK-4 and MK-7) in mature milk were determined by liquid chromatography-tandem mass spectrometry. The total concentration of vitamin K in mature milk was 4.50 (2.85-6.33) ng/mL. The concentrations of vitamin K1, vitamin K2, MK-4, and MK-7 were 2.81 (1.66-4.39) ng/mL, 1.37 (0.75-2.11) ng/mL, 1.20 (0.58-1.97) ng/mL, and 0.13 (0.08-0.19) ng/mL, respectively. The concentration of vitamin K1 was highest and the concentration of MK-7 was lowest. The concentrations of vitamin K2 and MK-4 in mature milk from the south were significantly higher than those in mature milk from the north. The total vitamin K, vitamin K2, and MK-4 concentrations in mature milk of lactating mothers residing in urban areas were higher than those in rural areas. There was a tendency for the concentration of total vitamin K and vitamin K1 to increase with the mother's age. Moreover, the concentration of MK-4 in mature milk was highest in summer, followed by spring and winter. The levels of vitamin K1 and MK-4 in mature milk were found to be affected by lactation stage; they were highest at 91-120 days and lowest at 31-60 days. Based on the concentration of vitamin K in mature milk found in this study, it is recommended that the appropriate intake of VK for Chinese infants aged 0-5 months is 3.49 μg/d (2.18 μg/d for VK1 and 1.06 μg/d for VK2).

Establishing reference ranges of serum vitamin K in healthy children

Objective: To establish and validate reference intervals of serum vitamin K for healthy children in China. Methods: A cross-sectional study was conducted from January 2020 to May 2023, involving 807 healthy children aged 0 to 14 years, selected by stratified random sampling based on the population distribution of children in eastern, central, western, and northeastern China. Sample collection was carried out in 16 hospitals across 12 provinces, autonomous regions, and municipalities. Basic information of the children was collected using a standardized self-design questionnaire. Serum levels of vitamin K1 and vitamin K2 (menaquinone-4 (MK-4), menaquinone-7 (MK-7)) were measured using liquid chromatography-tandem mass spectrometry. The reference intervals was established by direct approach. The children were divided into different groups by age. Inter-group comparisons were conducted using the Kruskal-Wallis non-parametric test, and the reference intervals (P2.5-P97.5) were determined using non-parametric methods. Screening 40 healthy children for small sample validation based on age groups within the reference range(25 from eastern, 10 from central, and 5 from western regions). Results: The age of the 807 children was 5.00 (2.00, 9.81) years, and 495 (61.3%) were males and 312 (38.7%) females. Reference intervals were established for 795 children, of whom 303 children were aged 1 month to 3 years and 492 were aged 4 to 14 years. The reference intervals for serum vitamin K1 were 0.09-4.54 μg/L for children aged 1 month to 3 years, and 0.10-1.73 μg/L for 4-14 years. For MK-7, the intervals were 0.07-1.42 μg/L for 1 month to 3 years and 0.19-2.03 μg/L for 4-14 years. The reference intervals for MK-4 in children aged 1 month to 14 years were 0-0.42 μg/L. The measured values of serum vitamin K1, MK-4, and MK-7 in the validation samples did not exceed the reference limit in more than 2 samples. Conclusion: Reference intervals for vitamin K1, MK-4, and MK-7 in healthy children aged 1 month to 14 years have been established and validated, and can be used to assess vitamin K nutritional status in children.

Short-term impact of vitamin K2 supplementation on biochemical parameters and lipoprotein fractions.

This study explored the short-term effects of vitamin K2 (VK2) supplementation on biochemical parameters (vitamin D, vitamin E, vitamin A, alkaline phosphatase, calcium, phosphorus (P), magnesium, metallothionein, triglycerides, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and lipoprotein fractions (albumin, HDL, very low-density lipoprotein (VLDL), LDL, and chylomicrons). A short-term experiment (24h, six probands) was performed to track changes in VK2 levels after a single-dose intake (360µg/day). Liquid chromatography-tandem mass spectrometry was used to monitor vitamin K levels (menaquinone-4 (MK-4), menaquinone-7 (MK-7), and vitamin K1 [VK1]) with a limit of detection of 1.9pg/mL for VK1 and 3.8pg/mL for the two forms of VK2. Results showed that MK-7 levels significantly increased within 2-6h post-administration and then gradually declined. MK-4 levels were initially low, showing a slight increase, whereas VK1 levels rose initially and then decreased. Biochemical analyses indicated no significant changes in sodium, chloride, potassium, calcium, magnesium, albumin, or total protein levels. A transient increase in P was observed, peaking at 12h before returning to baseline. Agarose gel electrophoresis of lipoprotein fractions revealed distinct chylomicron bands and variations in VLDL and HDL mobility, influenced by dietary lipids and VK2 supplementation. These findings suggest effective absorption and metabolism of MK-7 with potential implications for bone metabolism and cardiovascular health.

Vitamin K2 Supplementation in Hospitalised COVID-19 Patients: A Randomised Controlled Trial.

Background: In observational studies, high levels of desphospho-uncarboxylated matrix gla protein (dp-ucMGP) that result from vitamin K deficiency were consistently associated with poor clinical outcomes during COVID-19. Vitamin K-activated matrix gla protein (MGP) is required to protect against elastic fibre degradation, and a deficiency may contribute to pathology. However, intervention trials assessing the effects of vitamin K supplementation in COVID-19 are lacking. Methods: This is a single-centre, phase 2, double-blind, randomised, placebo-controlled trial investigating the effects of vitamin K2 supplementation in 40 hospitalised COVID-19 patients requiring supplemental oxygen. Individuals were randomly assigned in a 1:1 ratio to receive 999 mcg of vitamin K2-menaquinone-7 (MK-7)-or a placebo daily until discharge or for a maximum of 14 days. Dp-ucMGP, the rate of elastic fibre degradation quantified by desmosine, and hepatic vitamin K status quantified by PIVKA-II were measured. Grade 3 and 4 adverse events were collected daily. As an exploratory objective, circulating vitamin K2 levels were measured. Results: Vitamin K2 was well tolerated and did not increase the number of adverse events. A linear mixed model analysis showed that dp-ucMGP and PIVKA-II decreased significantly in subjects that received supplementation compared to the controls (p = 0.008 and p = 0.0017, respectively), reflecting improved vitamin K status. The decrease in dp-ucMGP correlated with higher plasma MK-7 levels (p = 0.015). No significant effect on desmosine was found (p = 0.545). Conclusions: These results demonstrate that vitamin K2 supplementation during COVID-19 is safe and decreases dp-ucMGP. However, the current dose of vitamin K2 failed to show a protective effect against elastic fibre degradation.

Serum 25(OH)D and vitamin K1 levels in patients with severe motor and intellectual disability: A Japanese single-center experience

PurposeTo investigate whether patients with severe motor and intellectual disability (SMID) have nutritional vitamin D and K insufficiencies and clarify the required vitamin supplementation. MethodsThis prospective observational study enrolled Japanese adults with SMID receiving institutionalized care who underwent blood sampling between February 2020 and February 2022 during annual medical checkups. Serum vitamin K1 and 25-hydroxy vitamin D (25(OH)D) levels were measured to determine their relationship with serum uncarboxylated osteocalcin (ucOC) levels. Vitamin D and K intake was compared among tube-fed and oral-intake patients with SMID and control participants using corresponding serum levels. ResultsThe study included 124 patients with SMID (56 men and 68 women; mean age: 53.0 years) and 20 control participants. Serum 25(OH)D levels were significantly higher in the SMID group than in the control group and the oral intake SMID group than in the tube-fed SMID group. In the tube-fed SMID group, vitamin D intake was lower than the daily recommended intake and correlated with serum 25(OH)D levels. Daily vitamin K intake in the tube-fed group was lower than recommended but not correlated with serum vitamin K levels. Serum ucOC levels were significantly higher in the SMID group than in the control group. Tube feeding was significantly and positively correlated with serum 25(OH)D levels. Serum 25(OH)D levels were not correlated with serum vitamin K1 levels. ConclusionsThe SMID group had higher ucOC levels than the control group, possibly owing to daily vitamin K and D deficiencies. Vitamin D supplementation is recommended to decrease ucOC levels.

Vitamin K Status Based on K1, MK-4, MK-7, and Undercarboxylated Prothrombin Levels in Adolescent and Adult Patients with Cystic Fibrosis: A Cross-Sectional Study.

The available evidence on vitamin K status in cystic fibrosis (CF) is scarce, lacking data on vitamin K2 (menaquinones-MK). Therefore, we assessed vitamin K1, MK-4 and MK-7 concentrations (LC-MS/MS) in 63 pancreatic insufficient and modulator naïve CF patients, and compared to 61 healthy subjects (HS). Vitamin K1 levels did not differ between studied groups. MK-4 concentrations were higher (median <1st-3rd quartile>: 0.778 <0.589-1.086> vs. 0.349 <0.256-0.469>, p < 0.0001) and MK-7 levels lower (0.150 <0.094-0.259> vs. 0.231 <0.191-0.315>, p = 0.0007) in CF patients than in HS. MK-7 concentrations were higher in CF patients receiving K1 and MK-7 supplementation than in those receiving vitamin K1 alone or no supplementation. Moreover, vitamin K1 concentrations depended on the supplementation regime. Based on multivariate logistic regression analysis, we have found that MK-7 supplementation dose has been the only predictive factor for MK-7 levels. In conclusion, vitamin K1 levels in CF are low if not currently supplemented. MK-4 concentrations in CF patients supplemented with large doses of vitamin K1 are higher than in HS. MK-7 levels in CF subjects not receiving MK-7 supplementation, with no regard to vitamin K1 supplementation, are low. There do not seem to be any good clinical predictive factors for vitamin K status.

Short-term treatment with cholestyramine increases long-acting anticoagulant rodenticide clearance from rabbits without affecting plasma vitamin K1 levels or blood coagulation.

Administration of high-dose vitamin K1 (VK1) overcomes coagulopathy and bleeding elicited by acute poisoning with long-acting anticoagulant rodenticides (LAARs). However, long-term (months) treatment is required due to long LAAR biological half-lives that may lead to poor compliance and recurrent coagulopathy. The half-lives of LAARs are extended by slow metabolism, and similar to warfarin, are thought to undergo enterohepatic recirculation. We now show that treatment with the bile acid sequestrant cholestyramine (CSA) administered concomitantly with VK1 decreases plasma LAAR levels and increases LAAR fecal excretion. Daily CSA treatment for 14 days did not reduce plasma VK1 levels, or increase prothrombin time. Collectively, these data show that CSA accelerates LAAR clearance from rabbits without adverse effects on VK1 anticoagulation, and could provide an additional therapeutic option for treatment of LAAR poisoning.

Post-bariatric pregnancy is associated with vitamin K1 deficiency, a case control study

BackgroundMaternal obesity is associated with adverse outcome for pregnancy and childbirths. While bariatric surgery may improve fertility and reduce the risk of certain pregnancy-related complications such as hypertension and gestational diabetes mellitus, there is a lack of evidence on the optimal nutritional monitoring and supplementation strategies in pregnancy following bariatric surgery. We aimed to assess the impact of bariatric surgery on micronutrients in post-bariatric pregnancy and possible differences between gastric bypass surgery and sleeve gastrectomy.MethodsIn this prospective case control study, we recruited 204 pregnant women (bariatric surgery n = 59 [gastric bypass surgery n = 26, sleeve gastrectomy n = 31, missing n = 2] and controls n = 145) from Akershus university hospital in Norway. Women with previous bariatric surgery were consecutively invited to study participation at referral to the clinic for morbid obesity and the controls were recruited from the routine ultrasound screening in gestational week 17–20. A clinical questionnaire was completed and blood samples were drawn at mean gestational week 20.4 (SD 4.5).ResultsThe women with bariatric surgery had a higher pre-pregnant BMI than controls (30.8 [SD 6.0] vs. 25.2 [5.4] kg/m2, p < 0.001). There were no differences between groups regarding maternal weight gain (bariatric surgery 13.3 kg (9.6) vs. control 14.8 kg (6.5), p = 0.228) or development of gestational diabetes (n = 3 [5%] vs. n = 7 [5%], p = 1.000). Mean levels of vitamin K1 was lower after bariatric surgery compared with controls (0.29 [0.35] vs. 0.61 [0.65] ng/mL, p < 0.001). Multiadjusted regression analyses revealed an inverse relationship between bariatric surgery and vitamin K1 (B -0.26 ng/mL [95% CI -0.51, -0.04], p = 0.047) with a fivefold increased risk of vitamin K1 deficiency in post-bariatric pregnancies compared with controls (OR 5.69 [1.05, 30.77] p = 0.044). Compared with sleeve gastrectomy, having a previous gastric bypass surgery was associated with higher risk of vitamin K1 deficiency (OR 17.1 [1.31, 223.3], p = 0.030).ConclusionPost-bariatric pregnancy is negatively associated with vitamin K1 with a higher risk of vitamin K1 deficiency in pregnancies after gastric bypass surgery compared with after sleeve gastrectomy. Vitamin K1 deficiency in post-bariatric pregnancy have potential risk of hypocoaguble state in mother and child and should be explored in future studies.

Clinical value of vitamin K testing in children aged 1-2 years with vitamin D deficiency rickets.

to investigate the clinical value of vitamin K testing in children with vitamin D deficiency rickets. fifty children with vitamin D deficiency rickets admitted to our hospital from March 2021 to March 2022 were recruited as the case group using convenience sampling; and an additional 50 children without bone health diseases during the same period of health checkup were selected as the control group. The relevant indexes between the two groups were compared. there were statistically significant differences between the two groups in the level of 25 hydroxyvitamin D3 [25-(OH)D3], the proportion of breastfeeding, and the proportion of preterm birth (p < 0.001). The levels of vitamin K1 and K2 were lower in the case group than in the control group, and the proportion of those with vitamin K1 deficiency and vitamin K2 deficiency were higher than the control group (p < 0.001) . Positive correlations were found between vitamins K1 and K2 and 25-(OH)D3, blood calcium, and blood phosphorus (p < 0.05); artificial feeding, preterm birth, vitamin K1 deficiency, and vitamin K2 deficiency were risk factors for the development of vitamin D deficiency rickets, and the highest AUC of the combination of each index in predicting the occurrence of vitamin D deficiency rickets was 0.951 (95 % CI: 0.910-0.991). preterm birth, artificial feeding, and vitamin K1 and K2 deficiency are independent risk factors for bone metabolism in children with vitamin D-deficiency rickets. And these risk factors have predictive and diagnostic value in the diagnosis and management of vitamin D deficiency rickets.

The mediation effect of vitamin A and vitamin D supplement in the association between serum vitamin K levels and musculoskeletal disorders in preschool children.

Vitamin K deficiency may elevate the incidence of musculoskeletal disorders (MSD), whereas it lacks validation for pediatric populations and has uncertain dose recommendations. In this context, we hypothesized that serum vitamin K levels are associated with MSD in preschool children, and the widely used vitamin A and vitamin D supplements may mediate these associations based on potential mechanisms, which expects to provide guidance for future practice. A cross-sectional study was conducted in Sichuan province in southwestern China, from January 2021 to May 2022. Serum levels of vitamin K1/K2 and 25(OH)D were determined using the high-performance liquid chromatography method, and the diagnosis of MSD was executed by clinicians. Overall and stratified logistic regression analysis based on categorized 25(OH)D levels were conducted to assess association between serum vitamin K levels and MSD prevalence after adjusting for confounders. Mediation analysis was further performed and vitamin A and D supplementation was regressed as the mediator. A total of 6,368 children aged 0-6 years old were enrolled. MSD was identified in 1179 (18.51%) of the children, while 5,189 (81.49%) of them did not present such disorder. After adjusting confounders, a significant difference was found in serum vitamin K1 level between children in MSD and Non-MSD group (OR = 0.802, 95%CI 0.745-0.864). No significant difference was found in serum vitamin K2 level between the two groups (OR = 0.975, 95%CI 0.753-1.261). The association between vitamin K1 level and MSD prevalence was partly (36.8%) mediated by vitamin A and D supplementation. A low serum vitamin K1 level is connected with an increased risk of MSD among children, highlighting that vitamin A and D supplementation is a helpful intervention to prevent MSD in children with vitamin K deficiency.

A Negative Association between Plasma Phylloquinone and All-Cause Mortality in Chinese Adults with Hypertension: A Nested Case-Control Study

BackgroundPrevious studies have revealed that vitamin K is essential for preventing various chronic diseases. Phylloquinone is the primary dietary and circulating form of vitamin K. However, data concerning the association between plasma phylloquinone and all-cause mortality are limited. ObjectivesThis study aimed to evaluate the association between plasma phylloquinone and risk of all-cause mortality and examine some potential confounders. MethodsThis study is a post hoc analysis of the RCT and a nested, case-control design was used. Enrolled participants had to have hypertension at baseline. Study initiation was 19 May, 2008, and the median follow-up was 4.5 y. A total of 604 mortality cases and 604 controls matched for age, sex, treatment group, and study site were included in this study. Odds ratios (OR) and 95% confidence intervals (CIs) of all-cause mortality were calculated using conditional or unconditional logistic regression, without or with adjusting for pertinent covariates, respectively. The concentration of phylloquinone was measured by liquid chromatography–tandem quadrupole mass spectrometry (LC-MS/MS). ResultsThe mean and median phylloquinone levels were 1.62 nmol/L and 0.89 nmol/L, respectively. There was a significant negative association between log-transformed plasma phylloquinone and all-cause mortality after controlling for potential confounders (per 1 unit increase-OR: 0.79; 95% CI: 0.66, 0.95). Furthermore, the association of plasma phylloquinone with risk of all-cause mortality differed by body mass index (BMI) (<25 kg/m2 compared with ≥25 kg/m2, P-interaction = 0.004). A significant trend of decreasing risk with increasing concentration of phylloquinone was observed in participants with higher BMI (per 1 unit increase-OR: 0.71; 95% CI: 0.56, 0.90; P = 0.004). No significant correlation was found between phylloquinone and risk of all-cause mortality in those with BMI <25 kg/m2. ConclusionsIn Chinese patients with hypertension, there was a significant negative association between baseline plasma phylloquinone and all-cause mortality, especially among those with higher BMI.

A Case Control Study Evaluating the Relationship between Vitamin K2 Serum Level and Periodontitis.

Vitamin K2 (VK2) is an essential co-factor for bone metabolism. There is still very little data regarding possible VK2 relation to periodontitis. This study aimed to investigate any potential link between VK2 serum level and the severity of periodontitis in comparison to a control group of healthy individuals. The trial was performed on 100 patients among whom 50 were diagnosed with periodontitis. The patients underwent full clinical periodontal and radiological examination. The VK2 serum level was assessed using the ELISA kit (Gla-type osteocalcin EIA Kit, Takara, Kusatsu). Patients with periodontitis had mean serum levels of VK2 significantly lower (0.27 ± 0.06 nmol/L; p < 0.001) than the control group (0.43 ± 0.09 nmol/L; p < 0.001) regardless of the patient's age or sex. The VK2 serum level decreased with the severity of periodontitis with the lowest level in stage IV of the disease (0.19 ± 0.01 nmol/L; p < 0.001). Also, a significant drop was noticed between the grades of periodontitis. Individuals with localized forms of the disease had significantly lower VK2 levels (0.26 ± 0.006 nmol/L; p < 0.001) in comparison to subjects with generalized periodontitis (0.30 ± 0.01 nmol/L; p < 0.001). The VK2 serum levels were also associated with most of the clinical parameters such as bleeding on probing (-0.805, 95% CI: -0.894 to -0.654, p < 0.001), attachment loss (-0.752, 95% CI: -0.862 to -0.574, p < 0.001), and bone loss (-0.656, 95% CI: -0.801 to -0.439, p < 0.001). In the present study, the VK2 serum level was correlated to periodontitis, and its severity, complexity, extension, and grade. The range of VK2 was decreasing together with the worsening of all clinical parameters of periodontitis.

ABCG5 and ABCG8 Are Involved in Vitamin K Transport.

ATP-binding cassette protein G5 (ABCG5)/ABCG8 heterodimer exports cholesterol from cells, while Niemann-Pick C1-like 1 (NPC1L1) imports cholesterol and vitamin K. We examined whether ABCG5/ABCG8 transports vitamin K similar to NPC1L1. Since high concentrations of vitamin K3 show cytotoxicity, the cytoprotective effects of ABCG5/ABCG8 were examined. BHK cells expressing ABCG5/ABCG8 were more resistant to vitamin K3 cytotoxicity than control cells, suggesting that ABCG5/ABCG8 transports vitamin K3 out of cells. The addition of vitamin K1 reversed the effects of ABCG5/ABCG8, suggesting that vitamin K1 competitively inhibits the transport of vitamin K3. To examine the transport of vitamin K1 by ABCG5/ABCG8, vitamin K1 levels in the medium and cells were measured. Vitamin K1 levels in cells expressing ABCG5/ABCG8 were lower than those in control cells, while vitamin K1 efflux increased in cells expressing ABCG5/ABCG8. Furthermore, the biliary vitamin K1 concentration in Abcg5/Abcg8-deficient mice was lower than that in wild-type mice, although serum vitamin K1 levels were not affected by the presence of Abcg5/Abcg8. These findings suggest that ABCG5 and ABCG8 are involved in the transport of sterols and vitamin K. ABCG5/ABCG8 and NPC1L1 might play important roles in the regulation of vitamin K absorption and excretion.

Low vitamin K status in adults with cystic fibrosis is associated with reduced body mass index, insulin secretion, and increased pseudomonal colonization.

Patients with cystic fibrosis(CF) are at high risk of fat-soluble vitamin deficiencies, even with supplementation. The contribution of a suboptimal vitamin K status to respiratory and endocrine pathophysiology in CF has been inadequately characterized. This is a cross-sectional study in adult CF patients(≥18 years old) from the Montreal Cystic Fibrosis Cohort. Vitamin K1(VK1) was measured with high-performance liquid chromatography, using fasted serum samples collected during an oral glucose tolerance test(OGTT: 2h with plasma glucose and insulin every 30min)(n=168). Patients were categorized according to VK1 status(suboptimal defined as<0.30nmol/L). Suboptimal VK1 levels were observed in 66% of patients. Patients with a suboptimal VK1 status have a higher risk of colonization with Pseudomonas aeruginosa(p=0.001), have lower body mass index(BMI)(p=0.003), and were more likely to have exocrine pancreatic insufficiency(p=0.002). Using an established threshold for VK1, we did show significantly reduced OGTT-derived measures of insulin secretion in patients with a VK1 status below 0.30nmol/L(first- and second-phase area under the curve (AUC)INS/GLU(p=0.002 and p=0.006), AUCINS(p=0.012) and AUCINS/GLU(p=0.004)). Subclinical vitamin K deficiency is more common than other fat-soluble vitamin deficiencies in patients with CF. We demonstrate an association between a suboptimal VK1 status and measures of insulin secretion. We highlight the potential associations of mild vitamin K deficiency with pseudomonal colonization and lower BMI, although these need to be validated in prospective studies.

Can Bone-Specific Alkaline Phosphatase be a Marker of Vascular Calcification in Type 2 Diabetes Mellitus?

Alkaline phosphatase (ALP) enzyme has been linked to vascular calcification. Unexplained elevations in serum ALP levels have been reported in patients with type 2 diabetes mellitus (T2DM). We assessed bone-specific alkaline phosphatase (BAP) levels in patients with T2DM who had unexplained ALP elevations and studied the association between BAP and other markers of vascular calcification. Patients with T2DM who had high serum ALP in the absence of known causes of ALP elevation were studied. The control group was T2DM patients with normal ALP. We measured the serum levels of BAP along with the leptin, fetuin-A, and vitamin K2 levels. Ankle-brachial index (ABI) was also measured in both groups. Serum BAP levels were significantly higher in the group with high ALP when compared with the normal ALP group. A significant positive correlation was present between BAP and serum fetuin-A as well as between BAP and Vit K2 levels. There was no correlation between BAP and serum leptin. ABI was comparable between the two groups. Patients with T2DM may have unexplained elevation in ALP due to an increase in BAP. Elevation in BAP may be associated with other markers of vascular calcification suggesting an increased risk of vascular calcification.