Examining Health Conditions, Impairments, and Quality of Life for Pediatric Feeding Disorders.

By understanding health conditions, impairments, and impact on quality of life for pediatric feeding disorders, assessment and treatment approaches can target multiple levels of health-related domains that improve child health and well-being. The purpose of this study was to characterize medical diagnoses and feeding impairments for children with feeding disorders; examine child quality of life and caregiver impact; and compare quality of life differences between children with feeding disorders and children with other conditions. A cross-sectional study was conducted in the Greater Boston Area, between October 2017 and June 2018. Fifty children with a feeding disorder diagnosis, ages 2-5 years, were enrolled. Demographic and clinical data were abstracted from the electronic health record to characterize medical diagnoses and impairments. Parents completed the Pediatric Quality of Life Generic Core Scales 4.0 (PedsQL) and the Feeding/Swallowing Impact Survey (FS-IS) to understand child quality of life and caregiver impact. We calculated descriptive statistics across the medical diagnosis and impairment groups, and for the surveys. Children presented with heterogeneous medical diagnoses and feeding impairments. We found a mean (SD) total score of 72.82(19.21) on the PedsQL and 2.33(0.89) on the FS-IS demonstrating that children with feeding disorders presented with poor quality of life and their caregivers were negatively impacted by their feeding difficulties. By understanding medical diagnoses, impairments, and quality of life, assessment and treatment methods can be tailored to children's specific needs, as well as address the overall wellbeing of children and their families.

Differential comorbidity profiles in avoidant/restrictive food intake disorder and anorexia nervosa: Does age play a role?

OBJECTIVE: Research comparing psychiatric comorbidities between individuals with avoidant/restrictive food intake disorder (ARFID) and anorexia nervosa (AN) is limited. ARFID often develops in childhood, whereas AN typically develops in adolescence or young adulthood. Understanding how age may impact differential psychological comorbidity profiles is important to inform etiological conceptualization, differential diagnosis, and treatment planning. We aimed to compare the lifetime frequency of psychiatric comorbidities and suicidality between females with ARFID (n = 51) and AN (n = 40), investigating the role of age as a covariate. METHOD: We used structured interviews to assess the comparative frequency of psychiatric comorbidities/suicidality. RESULTS: When age was omitted from analyses, females with ARFID had a lower frequency of depressive disorders and suicidality compared to AN. Adjusting for age, only suicidality differed between groups. DISCUSSION: This is the first study to compare comorbidities in a similar number of individuals with ARFID and AN, and a structured clinical interview to confer ARFID and comorbidities, covarying for age, and the first to compare suicidality. Although suicidality is at least three times less common in ARFID than AN, observed differences in other psychiatric comorbidities may reflect ARFID's relatively younger age of presentation compared to AN. PUBLIC SIGNIFICANCE: Our results highlight that, with the exception of suicidality, which was three times less common in ARFID than AN irrespective of age, observed differences in psychiatric comorbidities in clinical practice may reflect ARFID's younger age at clinical presentation compared to AN.

Elevated Fasting Satiety-Promoting Cholecystokinin (CCK) in Avoidant/Restrictive Food Intake Disorder Compared to Healthy Controls.

Objective: Avoidant/restrictive food intake disorder (ARFID) is characterized by food avoidance or dietary restriction not primarily motivated by body weight/shape concerns. Individuals with ARFID can report early satiation, post-prandial fullness, and high intermeal satiety, but whether these symptoms are related to differences in the biology underlying appetite regulation is unknown. In male and female children and adolescents, we hypothesized that fasting levels of cholecystokinin (CCK), a satiety hormone, would be elevated in participants with ARFID (full or subthreshold) versus healthy controls (HCs). Within the ARFID group, we also explored the relations of CCK with weight status, subjective appetite ratings, and ARFID severity and phenotypes.Methods: A total of 125 participants (83 with full/subthreshold ARFID (per DSM-5) and 42 HCs, aged 10.2-23.7 years; 61% female; July 2014-December 2019) underwent fasting blood draws for CCK, completed self-report measures assessing subjective state and trait appetite ratings, and completed a semistructured interview assessing ARFID severity.Results: Fasting CCK was higher in those with full/subthreshold ARFID versus HCs with a large effect (F1 = 25.0, P < .001, ηp2 = 0.17), controlling for age, sex, and body mass index (BMI) percentile. Within the ARFID group, CCK was not significantly related to BMI percentile, subjective appetite ratings, or ARFID characteristic measures.Conclusions: CCK may contribute to etiology and/or maintenance of ARFID, as children and adolescents with heterogeneous presentations of avoidant/restrictive eating appear to show elevated fasting levels compared to healthy youth. Further research is needed to understand relations between CCK and appetite, weight, and eating behavior in ARFID.

Pediatric weight management interventions improve prevalence of overeating behaviors.

OBJECTIVE: To examine changes in prevalence of overeating behaviors in a comparative effectiveness study of two pediatric weight management interventions. METHODS: Four-hundred and seven children, ages 6-12 years, with a BMI ≥ 85th percentile were enrolled in a comparative effectiveness trial of two pediatric weight management interventions. Prevalence of "sneaking, hiding or hoarding food", and 'eating in the absence of hunger' was evaluated at baseline and 12 months. Statistical methods included McNemar's test and longitudinal logistic regression. RESULTS: Prevalence of "sneak, hide, or hoard food" significantly decreased in all participants from 29.1% to 20.7% at 12 months. The prevalence of "eating in the absence of hunger" decreased in all participants from 46.7% to 22.4% at 12 months. Use of SNAP benefits, free/reduced meals at school, parental stress, housing, and food insecurity at baseline were associated with an increased likelihood of endorsing overeating behaviors at 12 months. Conversely, those who engaged in at least one session of the pediatric weight management intervention were significantly less likely to endorse "eating in the absence of hunger" at 12 months. CONCLUSIONS: Participation in pediatric weight management interventions improves the prevalence of overeating behaviors and is associated with participant engagement and social determinants of health, specifically food security status. Efforts to engage populations impacted by food insecurity and other social determinants of health risk factors will be critical for success of weight management interventions. CLINICAL TRIAL REGISTRATION: This trial has been registered at ClinicalTrials.gov (identifier: NCT03012126).

Neurobiology of Avoidant/Restrictive Food Intake Disorder in Youth with Overweight/Obesity Versus Healthy Weight.

OBJECTIVE: Avoidant/restrictive food intake disorder (ARFID) occurs across the weight spectrum, however research addressing the coexistesnce of ARFID with overweight/obesity (OV/OB) is lacking. We aimed to establish co-occurrence of OV/OB and ARFID and to characterize divergent neurobiological features of ARFID by weight. METHOD: Youth with full/subthreshold ARFID (12 with healthy weight [HW], 11 with OV/OB) underwent fasting brain fMRI scan while viewing food/non-food images (M age = 16.92 years, 65% female, 87% white). We compared groups on BOLD response to high-calorie foods (HCF) (vs. objects) in food cue processing regions of interest. Following fMRI scanning, we evaluated subjective hunger pre- vs. post-meal. We used a mediation model to explore the association between BMI, brain activation, and hunger. RESULTS: Participants with ARFID and OV/OB demonstrated significant hyperactivation in response to HCF (vs. objects) in the orbitofrontal cortex (OFC) and anterior insula compared with HW participants with ARFID. Mediation analysis yielded a significant indirect effect of group (HW vs. OV/OB) on hunger via OFC activation (effect = 18.39, SE = 11.27, 95% CI [-45.09, -3.00]), suggesting that OFC activation mediates differences in hunger between ARFID participants with HW and OV/OB. CONCLUSIONS: Compared to youth with ARFID and HW, those with OV/OB demonstrate hyperactivation of brain areas critical for the reward value of food cues. Postprandial changes in subjective hunger depend on BMI and are mediated by OFC activation to food cues. Whether these neurobiological differences contribute to selective hyperphagia in ARFID presenting with OV/OB and represent potential treatment targets is an important area for future investigation.

Prevalence and Characteristics of Avoidant/Restrictive Food Intake Disorder in Pediatric Neurogastroenterology Patients.

ABSTRACT: Recent reports document avoidant/restrictive food intake disorder (ARFID) symptoms among 13-40% of adults presenting to neurogastroenterology clinics, but ARFID in pediatrics is understudied. We conducted a retrospective review of charts from 129 consecutive referrals (ages 6-18 years; 57% female) for pediatric neurogastroenterology examination, from January 2016 through December 2018. Eleven cases (8%) met the full criteria for ARFID by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition and 19 cases (15%) had clinically significant avoidant/ restrictive eating behaviors with insufficient information for a definitive ARFID diagnosis. Of patients with ARFID symptoms (n = 30), 20 (67%) cited fear of gastrointestinal symptoms as motivation for their avoidant/ restrictive eating. Compared to patients without ARFID symptoms, patients with ARFID symptoms were older (P  < .001), more likely to be female (51% vs 79%, P  = 0.014), and more frequently presented with eating/weight-related complaints (15% vs 33%, P  = 0.026). This pilot retrospective study showed ARFID symptoms present in 23% of pediatric neurogastroenterology patients; further research is needed to understand risk and maintenance factors of ARFID in the neurogastroenterology setting.

Characterization of the blood microbiota in children with Celiac disease.

Celiac Disease (CD) is an autoimmune disorder triggered by gluten ingestion that can develop in genetically predisposed individuals. Alterations in the gut microbiota have been suggested to contribute to development of autoimmune conditions including CD. Recent work suggests the existence of a blood microbiota. Evidence that alterations in the blood microbiota potentially influence the development of chronic immune based diseases is increasing. However, there is no published literature regarding the blood microbiota in children, including those with CD. This study aimed to characterize the diversity and taxonomic composition of the blood microbiota of children with CD compared to controls. Whole blood samples were collected from children with active CD, CD in remission, and control subjects and 16S rRNA sequencing was utilized to analyze the blood microbiota. We found 16s rRNA present throughout all pediatric blood samples, providing evidence for the presence of a pediatric blood microbiota. We found significant differences in beta diversity and in abundance of certain taxa (Campylobacterales order, Odoribacteraceae and Helicobacteraceae families, Odoribacter genus and species, and Bacteroides acidifaciens species) between subjects with active CD and controls. These taxa have been previously reported to be associated with immune response and gut-inflammatory diseases. We did not find significant differences between subjects with active and remission CD or between remission CD and controls. Conclusions: We provide evidence for a pediatric blood microbiota and identified higher beta diversity and alterations in the composition of blood microbiota in subjects with active CD compared to controls.

A Moving Target: How We Define Avoidant/Restrictive Food Intake Disorder Can Double Its Prevalence.

Objective: The DSM-5 criteria for avoidant/restrictive food intake disorder (ARFID) include ambiguities. Diagnostic criteria that allow for clinical judgment are essential for clinical practice. However, ambiguities can have major implications for treatment access and comparability and generalizability of research studies. The purpose of this study was to determine the degree to which distinct operationalizations of the diagnostic criteria for ARFID contribute to differences in the frequency of individuals who are eligible for the ARFID diagnosis.Methods: Because criteria B, C, and D are rule-outs, we focused on criterion A, identified 19 potential operational definitions, and determined the extent to which these different methods impacted the proportion of individuals who met criteria for ARFID in a sample of children, adolescents, and young adults (n = 80; September 2016-February 2020) enrolled in an avoidant/restrictive eating study.Results: Within each criterion, the proportion of individuals meeting diagnostic criteria differed significantly across the methodologies (all P values < .008). Using the strictest definition of each criterion, 50.0% (n = 40) of participants met criteria for ARFID. In contrast, under the most lenient definition of each criterion, the number nearly doubled, resulting in 97.5% (n = 78) meeting ARFID criteria.Conclusions: Comparison of diagnostic definitions for ARFID among children, adolescents, and young adults confirmed a broad range of statistically distinct proportions within a single sample. Our findings support the need for additional contextual support and consensus among disciplines on operationalization in both research and clinical settings.

Cognitive-behavioral therapy for adults with avoidant/restrictive food intake disorder.

There are currently no evidence-based treatments for adults with avoidant/restrictive food intake disorder (ARFID). The purpose of this study was to evaluate the acceptability, feasibility, and proof-of-concept of cognitive-behavioral therapy for ARFID (CBT-AR) for adults. Males and females (ages 18-55 years) were offered 20-30 outpatient sessions of CBT-AR delivered by one of five therapists. Of 18 eligible adults offered CBT-AR, 15 chose to participate and 14 completed treatment. All patients endorsed high ratings of treatment credibility and expected improvement after the first session, and 93% of completers provided high ratings of satisfaction at the conclusion of treatment. Therapists rated the majority (80%) of patients as "much improved" or "very much improved." Based on intent-to-treat analyses, ARFID severity on the Pica, ARFID, and Rumination Disorder Interview (PARDI) showed a large and significant decrease from pre- to post-treatment; and patients incorporated a mean of 18.0 novel foods. The underweight subgroup (n = 4) gained an average of 11.38 pounds, showing a large and significant increase in mean BMI from the underweight to the normal-weight range. At post-treatment, 47% of patients no longer met criteria for ARFID. To our knowledge, this is the first prospective treatment study of ARFID in adults. The findings of this study provide preliminary evidence of feasibility, acceptability, and proof-of-concept of CBT-AR for heterogeneous presentations of ARFID in adults. Randomized controlled trials are needed to confirm these findings. ClinicalTrials.gov Identifier: NCT02963220.

Cognitive-behavioral therapy for avoidant/restrictive food intake disorder: Feasibility, acceptability, and proof-of-concept for children and adolescents.

OBJECTIVE: Little is known about the optimal treatment of avoidant/restrictive food intake disorder (ARFID). The purpose of this study was to evaluate feasibility, acceptability, and proof-of-concept for cognitive-behavioral therapy for ARFID (CBT-AR) in children and adolescents. METHOD: Males and females (ages 10-17 years) were offered 20-30 sessions of CBT-AR delivered in a family-based or individual format. RESULTS: Of 25 eligible individuals, 20 initiated treatment, including 17 completers and 3 dropouts. Using intent-to-treat analyses, clinicians rated 17 patients (85%) as "much improved" or "very much improved." ARFID severity scores (on the Pica, ARFID, and Rumination Disorder Interview) significantly decreased per both patient and parent report. Patients incorporated a mean of 16.7 (SD = 12.1) new foods from pre- to post-treatment. The underweight subgroup showed a significant weight gain of 11.5 (SD = 6.0) pounds, moving from the 10th to the 20th percentile for body mass index. At post-treatment, 70% of patients no longer met criteria for ARFID. DISCUSSION: This is the first study of an outpatient manualized psychosocial treatment for ARFID in older adolescents. Findings provide evidence of feasibility, acceptability, and proof-of-concept for CBT-AR. Randomized controlled trials are needed.

The effect of vitamin K insufficiency on histological and structural properties of knee joints in aging mice.

Objective: While a role for vitamin K in maintaining joint tissue homeostasis has been proposed based on the presence of vitamin K dependent proteins in cartilage and bone, it is not clear if low vitamin K intake is causally linked to joint tissue degeneration. To address this gap, we manipulated vitamin K status in aging mice to test its effect on age-related changes in articular cartilage and sub-chondral bone. Methods: Eleven-month old male C57BL6 mice were randomly assigned to a low vitamin K diet containing 120 mcg phylloquinone/kg diet (n = 32) or a control diet containing 1.5 mg phylloquinone/kg diet (n = 30) for 6 months. Knees were evaluated histologically using Safranin O and H&E staining, as well as using micro-CT. Results: Eleven mice in the low vitamin K diet group and three mice in the control group died within the first 100 days of the experiment (p = 0.024). Mice fed the low vitamin K diet had higher Safranin-O scores, indicative of more proteoglycan loss, compared to mice fed the control diet (p ≤ 0.026). The articular cartilage structure scores did not differ between the two groups (p ≥ 0.190). The sub-chondral bone parameters measured using micro CT also did not differ between the two groups (all p ≥ 0.174). Conclusion: Our findings suggest low vitamin K status can promote joint tissue proteoglycan loss in older male mice. Future studies are needed to confirm our findings and obtain a better understanding of the molecular mechanisms underlying the role of vitamin K in joint tissue homeostasis.

Maternal Fish Consumption in Pregnancy Is Associated with a Bifidobacterium-Dominant Microbiome Profile in Infants.

National guidelines suggest that pregnant women consume 2-3 servings of fish weekly and often focus exclusively on limiting mercury exposure. We examined if meeting this recommendation in the third trimester of pregnancy was associated with differences in infant fecal microbiota composition and diversity. We used multinomial regression to analyze data from 114 infant-mother dyads. Applying 16S rRNA gene sequencing, we identified 3 infant fecal microbiota profiles: Bifidobacterium dominant, Enterobacter dominant, and Escherichia dominant. We found that 20% of mothers met the recommended fish consumption, and those infants whose mothers met the recommendation were more likely to have a Bifidobacterium-dominant profile than an Escherichia-dominant profile (RR ratio: 4.61; 95% CI: 1.40, 15.15; P = 0.01). In multivariable models, the significant association persisted (P < 0.05). Our findings support the need to expand recommendations focusing on the beneficial effects of fish consumption on the infant fecal microbiota profile.

A Diet High in Processed Foods, Total Carbohydrates and Added Sugars, and Low in Vegetables and Protein Is Characteristic of Youth with Avoidant/Restrictive Food Intake Disorder.

Avoidant/restrictive food intake disorder (ARFID) is characterized in part by limited dietary variety, but dietary characteristics of this disorder have not yet been systematically studied. Our objective was to examine dietary intake defined by diet variety, macronutrient intake, and micronutrient intake in children and adolescents with full or subthreshold ARFID in comparison to healthy controls. We collected and analyzed four-day food record data for 52 participants with full or subthreshold ARFID, and 52 healthy controls, aged 9-22 years. We examined frequency of commonly reported foods by logistic regression and intake by food groups, macronutrients, and micronutrients between groups with repeated-measures ANOVA. Participants with full or subthreshold ARFID did not report any fruit or vegetable category in their top five most commonly reported food categories, whereas these food groups occupied three of the top five groups for healthy controls. Vegetable and protein intake were significantly lower in full or subthreshold ARFID compared to healthy controls. Intakes of added sugars and total carbohydrates were significantly higher in full or subthreshold ARFID compared to healthy controls. Individuals with full or subthreshold ARFID had lower intake of vitamins K and B12, consistent with limited vegetable and protein intake compared to healthy controls. Our results support the need for diet diversification as part of therapeutic interventions for ARFID to reduce risk for nutrient insufficiencies and related complications.

Radcliffe ARFID Workgroup: Toward operationalization of research diagnostic criteria and directions for the field.

OBJECTIVE: Since its introduction to the psychiatric nomenclature in 2013, research on avoidant/restrictive food intake disorder (ARFID) has proliferated highlighting lack of clarity in how ARFID is defined. METHOD: In September 2018, a small multi-disciplinary pool of international experts in feeding disorder and eating disorder clinical practice and research convened as the Radcliffe ARFID workgroup to consider operationalization of DSM-5 ARFID diagnostic criteria to guide research in this disorder. RESULTS: By consensus of the Radcliffe ARFID workgroup, ARFID eating is characterized by food avoidance and/or restriction, involving limited volume and/or variety associated with one or more of the following: weight loss or faltering growth (e.g., defined as in anorexia nervosa, or by crossing weight/growth percentiles); nutritional deficiencies (defined by laboratory assay or dietary recall); dependence on tube feeding or nutritional supplements (≥50% of daily caloric intake or any tube feeding not required by a concurrent medical condition); and/or psychosocial impairment. CONCLUSIONS: This article offers definitions on how best to operationalize ARFID criteria and assessment thereof to be tested in existing clinical populations and to guide future study to advance understanding and treatment of this heterogeneous disorder.

Atorvastatin Decreases Renal Menaquinone-4 Formation in C57BL/6 Male Mice.

BACKGROUND: Menaquinone-4 (MK4), a vitamin K metabolite, is converted from phylloquinone through a process that requires intermediates of endogenous cholesterol production. Recent evidence suggests that MK4 is involved in kidney function. OBJECTIVE: The purpose of this study was to determine the effect of atorvastatin treatment on MK4 formation in young and old male mice. METHODS: C57BL/6 male mice (4-mo-old and 20-mo-old) were randomly assigned to either a diet containing 300 mg atorvastatin/kg with 3 mg phylloquinone/kg or a control diet containing 3 mg phylloquinone/kg for 8 wk. During week 8, all mice received deuterium-labeled phylloquinone in the diet. Labeled and unlabeled phylloquinone and MK4 in liver, kidney, brain, and intestine were measured by atmospheric pressure chemical ionization LC/MS. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase gene expression was quantified by reverse transcriptase-PCR. Tissue MK4 and phylloquinone concentrations were compared between atorvastatin treatment groups with use of general linear models. RESULTS: There was no age-treatment interaction on MK4 tissue concentrations. In atorvastatin-treated mice, total MK4 and percentage of deuterium-labeled MK4 in kidney were both approximately 45% lower compared to values in mice not given atorvastatin (all P < 0.05). MK4 concentrations did not differ between groups in any other tissue measured. CONCLUSION: In male mice, atorvastatin reduced endogenous MK4 formation in the kidney, but not other organs. These observations are consistent with our hypothesis that cholesterol metabolism is involved in the generation of MK4. Further research is needed to understand potential regulatory mechanisms and the unique functions of MK4 in the kidney.

Vegetables and Mixed Dishes Are Top Contributors to Phylloquinone Intake in US Adults: Data from the 2011-2012 NHANES.

Background: Phylloquinone is the most abundant form of vitamin K in US diets. Green vegetables are considered the predominant dietary source of phylloquinone. As our food supply diversifies and expands, the food groups that contribute to phylloquinone intake are also changing, which may change absolute intakes. Thus, it is important to identify the contributors to dietary vitamin K estimates to guide recommendations on intakes and food sources.Objective: The purpose of this study was to estimate 1) the amount of phylloquinone consumed in the diet of US adults, 2) to estimate the contribution of different food groups to phylloquinone intake in individuals with a high or low vegetable intake (≥2 or <2 cups vegetables/d), and 3) to characterize the contribution of different mixed dishes to phylloquinone intake.Methods: Usual phylloquinone intake was determined from NHANES 2011-2012 (≥20 y old; 2092 men and 2214 women) and the National Cancer Institute Method by utilizing a complex, stratified, multistage probability-cluster sampling design.Results: On average, 43.0% of men and 62.5% of women met the adequate intake (120 and 90 µg/d, respectively) for phylloquinone, with the lowest self-reported intakes noted among men, especially in the older age groups (51-70 and ≥71 y). Vegetables were the highest contributor to phylloquinone intake, contributing 60.0% in the high-vegetable-intake group and 36.1% in the low-vegetable-intake group. Mixed dishes were the second-highest contributor to phylloquinone intake, contributing 16.0% in the high-vegetable-intake group and 28.0% in the low-vegetable-intake group.Conclusion: Self-reported phylloquinone intakes from updated food composition data applied to NHANES 2011-2012 reveal that fewer men than women are meeting the current adequate intake. Application of current food composition data confirms that vegetables continue to be the primary dietary source of phylloquinone in the US diet. However, mixed dishes and convenience foods have emerged as previously unrecognized but important contributors to phylloquinone intake in the United States, which challenges the assumption that phylloquinone intake is a marker of a healthy diet. These findings emphasize the need for the expansion of food composition databases that consider how mixed dishes are compiled and defined.

Multiple Vitamin K Forms Exist in Dairy Foods.

Background: The plant-based form of vitamin K (phylloquinone, vitamin K-1) has been well quantified in the US diet. Menaquinones (vitamin K-2) are another class of vitamin K compounds that differ from phylloquinone in the length and saturation of their side chain, but they have not been well characterized in foods. Objectives: The objectives of this study were to 1) quantify phylloquinone and the different forms of menaquinones [menaquinone (MK) 4-MK13] in milk, yogurt, Greek yogurt, creams, and cheeses and 2) compare the menaquinone contents of full-fat, reduced-fat, and nonfat dairy products. Methods: All dairy samples were either obtained from the USDA National Food and Nutrient Analysis Program or purchased from retail outlets. Phylloquinone and menaquinone concentrations in these dairy products were quantified by mass spectrometry technology. Results: Full-fat dairy products contained appreciable amounts of menaquinones, primarily in the forms of MK9, MK10, and MK11. We also measured modest amounts of phylloquinone, MK4, MK8, and MK12 in these products. In contrast, there was little MK5-7 or MK13 detected in the majority of dairy products. The total vitamin K contents of soft cheese, blue cheese, semi-soft cheese, and hard cheese were (means ± SEMs): 506 ± 63, 440 ± 41, 289 ± 38, and 282 ± 5.0 µg/100 g, respectively. Nonfermented cheeses, such as processed cheese, contained lower amounts of vitamin K (98 ± 11 µg/100 g). Reduced-fat or fat-free dairy products contained ∼5-22% of the vitamin K found in full-fat equivalents. For example, total vitamin K contents of full-fat milk (4% fat), 2%-fat milk, 1%-fat milk, and nonfat milk were 38.1 ± 8.6, 19.4 ± 7.7, 12.9 ± 2.0, and 7.7 ± 2.9 µg/100 g, respectively. Conclusions: To the best of our knowledge, this is the first report of menaquinone contents of US dairy products. Findings indicate that the amount of vitamin K contents in dairy products is high and proportional to the fat content of the product.

The Role of Vitamin K in Chronic Aging Diseases: Inflammation, Cardiovascular Disease, and Osteoarthritis.

Vitamin K is an enzyme cofactor required for the carboxylation of vitamin K dependent proteins, several of which have been implicated in diseases of aging. Inflammation is recognized as a crucial component of many chronic aging diseases and evidence suggests vitamin K has an anti-inflammatory action that is independent of its role as an enzyme co-factor. Vitamin K-dependent proteins and inflammation have been implicated in cardiovascular disease and osteoarthritis, which are leading causes of disability and mortality in older adults. The purpose of this review is to summarize observational studies and randomized trials focused on vitamin K status and inflammation, cardiovascular disease, and osteoarthritis. Although mechanistic evidence suggests a protective role for vitamin K in these age-related conditions, the benefit of vitamin K supplementation is controversial because observational data are equivocal and the number of randomized trials is few.

Tissue Concentrations of Vitamin K and Expression of Key Enzymes of Vitamin K Metabolism Are Influenced by Sex and Diet but Not Housing in C57Bl6 Mice.

BACKGROUND: There has been limited characterization of biological variables that impact vitamin K metabolism. This gap in knowledge can limit the translation of data obtained from preclinical animal studies to future human studies. OBJECTIVE: The purpose of this study was to determine the effects of diet, sex, and housing on serum, tissue, and fecal vitamin K concentrations and gene expression in C57BL6 mice during dietary vitamin K manipulation. METHODS: C57BL6 4-mo-old male and female mice were randomly assigned to conventional or suspended-wire cages and fed control [1400 ± 80 µg phylloquinone (PK)/kg] or deficient (31 ± 0.45 µg PK/kg) diets for 28 d in a factorial design. PK and menaquinone (MK) 4 plasma and tissue concentrations were measured by HPLC. Long-chain MKs were measured in all matrices by LC-atmospheric pressure chemical ionization-mass spectrometry. Gene expression was quantified by reverse transcriptase-polymerase chain reaction in the liver, brain, kidney, pancreas, and adipose tissue. RESULTS: Male and female mice responded differently to dietary manipulation in a tissue-dependent manner. In mice fed the control diet, females had ∼3-fold more MK4 in the brain and mesenteric adipose tissue than did males and 100% greater PK concentrations in the liver, kidney, and mesenteric adipose tissue than did males. In mice fed the deficient diet, kidney MK4 concentrations were ∼4-fold greater in females than in males, and there were no differences in other tissues. Males and females differed in the expression of vitamin K expoxide reductase complex 1 (Vkorc1) in mesenteric adipose tissue and the pancreas and ubiA domain-containing protein 1 (Ubiad1) in the kidney and brain. There was no effect of housing on serum, tissue, or fecal concentrations of any vitamin K form. CONCLUSIONS: Vitamin K concentrations and expression of key metabolic enzymes differ between male and female mice and in response to the dietary PK concentration. Identifying factors that may impact study design and outcomes of interest is critical to optimize study parameters examining vitamin K metabolism in animal models.