Comparative Performance Assessment of Novel Fluorescence Immunoassay POCTs for Measuring Circulating Levels of Vitamin-D.

Vitamin D (Vit D) is a fat-soluble molecule acting like a hormone, and it is involved in several biological mechanisms such as gene expression, calcium homeostasis, bone metabolism, immune modulation, viral protection, and neuromuscular functions. Vit D deficiency can lead to chronic hypocalcemia, hyperparathyroidism, and many other pathological conditions; in this context, low and very low levels of 25-hydroxy-vitamin D (25-OH-D) were found to be associated with an increased risk of COVID-19 infection and the likelihood of many severe diseases. For all these reasons, it is important to quantify and monitor 25-OH-D levels to ensure that the serum/blood concentrations are not clinically suboptimal. Serum concentration of 25-OH-D is currently the main indicator of Vit D status, and it is currently performed by different assays, but the most common quantitation techniques involve immunometric methods or chromatography. Nevertheless, other quantitation techniques and instruments are now emerging, such as AFIAS-1® and AFIAS-10® (Boditech and Menarini) based on the immunofluorescence analyzer, that guarantee an automated system with cartridges able to give quick and reliable results as a point-of-care test (POCT). This work aims to compare AFIAS-1® and AFIAS-10® (Boditech and Menarini) Vit D quantitation with Ultra High-Performance Liquid Chromatography coupled with tandem mass spectrometry that currently represents the gold standard technique for Vit D quantitation. The analyses were performed in parallel on 56 samples and in different conditions (from fresh and frozen plasma) to assess the reliability of the results. Any statistically significant differences in methods, the fixed error, and the error proportional to concentration were reported. Results obtained in all conditions showed a good correlation between both AFIAS® instruments and LC-MS/MS, and we can affirm that AFIAS-1® and AFIAS-10® are reliable instruments for measuring 25-OH-D with accuracy and in a fast manner.

Analytical performance specifications for the measurement uncertainty of 24,25-dihydroxyvitamin D examinations.

OBJECTIVES: The exploration of the metabolites in the degradation pathways of vitamin D (VTD) has gained importance in recent years and simultaneous quantitation of twenty-five-hydroxy vitamin D (25(OH)D) mass concentration together with 24,25-dihydroxyvitamin D (24,25(OH)2D) has been proposed as a newer approach to define VTD deficiency. Yet, no data are available on 24,25(OH)2D biological variation (BV). In this study, we evaluated 24,25(OH)2D's BV on the European Biological Variation Study (EuBIVAS) cohort samples to determine if analytical performance specifications (APS) for 24,25(OH)2D could be generated. METHODS: Six European laboratories recruited 91 healthy participants. 25(OH)D and 24,25(OH)2D concentrations in K3-EDTA plasma were examined weekly for up to 10 weeks in duplicate with a validated LC-MS/MS method. The Vitamin D Metabolite Ratio (24,25(OH)2D divided by 25(OH)D × 100) was also calculated at each time point. RESULTS: Linear regression of the mean 24,25(OH)2D concentrations at each blood collection showed participants were not in steady state. Variations of 24,25(OH)2D over time were significantly positively associated with the slopes of 25(OH)D concentrations over time and the concentration of 25(OH)D of the participant at inclusion, and negatively associated with body mass index (BMI), but not with age, gender, or location of the participant. The variation of the 24,25(OH)2D concentration in participants over a 10 weeks period was 34.6%. Methods that would detect a significant change linked to the natural production of 24,25(OH)2D over this period at p<0.05 would need a relative measurement uncertainty (u%)<14.9% while at p<0.01, relative measurement uncertainty should be <10.5%. CONCLUSIONS: We have defined for the first time APS for 24,25(OH)2D examinations. According to the growing interest in this metabolite, several laboratories and manufacturers might aim to develop specific methods for its determination. The results presented in this paper are thus necessary prerequisites for the validation of such methods.

Undisclosed interference in 25-OH-Vitamin D immunoassay on Liaison XL analyzer when using heparin plasma tubes.

This study investigates the impact of sample type on the measurement of 25-OH-vitamin D using the Liaison XL (Diasorin) and Cobas e801 (Roche). This investigation was motivated by the need to optimize sample volume usage, which led us to adopt the use of heparin plasma, an alternative proposed by Diasorin in their specification. Discordant and unexplainable results were observed, prompting us to evaluate the effect of sample type on the accuracy of the 25-OH-vitamin D measurements. We collected 34 different paired samples from a randomly selected patients who had two types of tubes taken simultaneously: serum-gel and lithium-heparin plasma tubes. The 25-OH-vitamin D levels were measured using Cobas e801 and Liaison. Statistical analysis was performed using the Mann-Whitney test to calculate the p-value. Biases were also calculated. When comparing the heparin matrix with the serum matrix on the Liaison XL analyzer, a higher proportion (p < .0001; 79% versus 64%) of patients were classified in the 'normal group', while fewer were classified in the 'insufficiency' or 'deficiency group'. The heparin tubes on the Liaison XL analyzer showed a mean bias of 57.5%) (p-value < .001; 95%CI: 37.6-77.4) compared to the serum tubes. On the other hand, the heparin tubes on the Cobas e801 analyzer showed a mean bias of -0.2% (95%CI: -4.8 to 4.5) compared to the serum tubes. It is imperative for laboratory professionals to be aware of this interference for an accurate measurement of 25-OH-vitamin D levels on the Liaison XL. Further research is needed to understand the mechanism of this interference.

Association of vitamin D status with disease severity and outcome in Indian patients with IgA nephropathy.

BACKGROUND: Vitamin D deficiency has been examined as a risk factor for severity and progression of kidney disease due to its immunomodulatory effects. There is paucity of data about its impact in IgA nephropathy (IgAN). METHODS: In a retrospective cohort study, 25 (OH) vitamin D assay was performed in bio-banked baseline serum samples collected during kidney biopsy of 105 adult patients with primary IgAN diagnosed between 2015 and 2019. A level of < 10 ng/mL was defined as Vitamin D deficiency. RESULTS: Mean age of patients was 34 ± 10.6 years, 69.5% were males. Mean baseline 25(OH) Vitamin D levels was 15.9 ± 11.9 ng/mL and 41(39%) patients had vitamin D deficiency. Serum albumin level was lower in vitamin D deficient patients compared to those who had higher vitamin D levels (3.7 ± 0.9 vs 4.1 ± 0.7 g/dl, p = 0.018)but there was no significant difference in baseline proteinuria and eGFR. Crescentic lesions were more frequent in vitamin D deficient group (19.5% vs 6.3%, p = 0.022). At median follow up of 21.5 months (6 - 56 months), there was no difference in remission (68.3% vs 65.6%, p = 0.777) and disease progression (12.5% vs 9.4%, p = 0.614) in those with and without Vitamin D deficiency respectively. On multivariate cox proportional hazard analysis, vitamin D deficiency was not a significant risk factor for renal survival (HR-1.79, 95% confidence interval:0.50-6.34, p = 0.368). CONCLUSION: There was no association between vitamin D deficiency and disease profile as well as renal outcome in Indian patients with IgAN.

Assessment of Osteoporosis and Vitamin D3 Deficiency in Patients with Idiopathic Benign Paroxysmal Positional Vertigo (BPPV).

Background and objectives: Osteoporosis and vitamin D3 deficiency may be risk factors of benign paroxysmal positional vertigo (BPPV). The aim of this study was to assess the prevalence of osteoporosis and 25(OH) vitamin D3 deficiency in a group of patients with idiopathic benign paroxysmal positional vertigo. Materials and Methods: Thirty-five patients (twenty-eight women and seven men) with posterior semicircular canal BPPV were enrolled in the study. The subjects underwent hearing assessment (tonal audiometry and impedance audiometry) and the Dix-Hallpike maneuver. Serum 25(OH) vitamin D3 levels were determined and lumbar spine bone densitometry was performed. The relationships between sex, age, height, Body Mass Index (BMI), vitamin D3 levels and bone densitometry results were assessed. Results: The diagnosis of osteoporosis was confirmed in 1 patient (3%), 3 subjects were osteopenic (8.6%), and normal bone densitometry was found in 31 (88.6%) patients. Conclusions: We found no statistically significant relationships between age, BMI or vitamin D3 levels and bone densitometry results in patients with idiopathic BPPV.

Serum vitamin D levels and inflammatory status in COVID-19 patients.

OBJECTIVES: The coronavirus 2019 disease (COVID-19) is characterized by a heterogeneous clinical presentation, a complex pathophysiology and a wide range of laboratory findings, depending on disease severity. BACKGROUND: We studied some laboratory parameters in correlation with vitamin D status representing the inflammatory state in hospitalized COVID-19 patients on admission. METHODS: The study included 100 COVID-19 patients with moderate (n=55) and severe (n=45) form of the disease. Complete blood count and differential blood count, routine biochemical parameters, C-reactive protein and serum procalcitonin, ferritin, human IL-6 and serum vitamin D (measured as 25-OH vitamin D) concentrations, were performed. RESULTS: According to the severity of the disease, patients with severe form had significantly lower serum vitamin D (16.54±6.51 ng/ml vs 20.37±5.63 ng/ml, p=0.0012), higher serum interleukin-6 (41.24±28.46 pg/ml vs. 24.75±16.28 pg/ml, p=0.0003), C-reactive protein (101.49± 57.15 mg/l vs 74.43±42.99 mg/l, p=0.0044), ferritin (969.89±338.37 ng/ml vs 845.96±359.91 ng/ml, p=0.0423) and LDH (1050.53±369.11 U/l vs 905.31±335.57 U/l, p=0.0222) compared to those with moderate form of the disease. CONCLUSION: The presented data provide a relationship between increased inflammatory laboratory markers, low vitamin D levels and disease severity in COVID-19 patients (Tab. 2, Fig. 3, Ref. 32).

EFFECTS OF OMEGA-3 FATTY ACIDS ASSOCIATED WITH ANTIOXIDANT VITAMINS IN OVERWEIGHT AND OBESE CHILDREN.

Introduction: Antioxidants and unsaturated fatty acids have protective effects in obesity. Aim: We investigated the benefits of Omega-3 fatty acids associated with antioxidant vitamins in obese children. Magnesemia and calcemia were observed in relation with other metabolic parameters, before and after the treatment. Materials and methods: 60 obese children were compared with 35 normal weight children. Each obese child received daily, one pill, containing: 130mg docosahexaenoic acid, 25mg of eicosapentaenoic acid, vitamin A 200µg, vitamin D 1,25µg, vitamin E 2,5mg and vitamin C 30mg for three months. All the participants were instructed not to change their lifestyle. Results: The serum values for these minerals and for 25(OH) vitamin D were lower in obese children. The obese children had insulin resistance (HOMA-IR) and an imbalance of serum adipocytokines. In obese children, the body mass index was negatively correlated with calcemia (r=-0.34) and serum 25(OH) vitamin D (r=-0.33). The HOMA-IR was negatively correlated with magnesemia (r=-0.34) and serum adiponectin (r=-0.29). The treatment improved the mineral serum level, the insulin sensitivity and the adipocytokines levels. Conclusion: In obese children, the intake of Omega-3 fatty acids associated with antioxidant vitamins, for three months improved calcemia and magnesemia and increased insulin sensitivity.

25-Hydroxyvitamin D Serum Levels Linked to Single Nucleotide Polymorphisms (SNPs) (rs2228570, rs2282679, rs10741657) in Skeletal Muscle Aging in Institutionalized Elderly Men Not Supplemented with Vitamin D.

Sarcopenia (Sp) is the loss of skeletal muscle mass associated with aging that results in an involution of muscle function and strength. Vitamin D deficiency is a common health problem worldwide, especially among the elderly, and hypovitaminosis D leads to musculoskeletal disorders. The aim of this study was to evaluate the impact and presence of a possible linkage between Single Nucleotide Polymorphisms (SNPs) CYP2R1 (rs10741657), GC (rs2282679), and VDR (rs2228570), serum 25-OH/D concentrations and the link with the degree of sarcopenia in 19 institutionalized elderly men not supplemented with vitamin D. Levels of 25-OH vitamin D were quantified with a commercial enzyme-linked immunosorbent assay kit and 3 SNPs were genotyped with KASPar assays. Significant differences in 25-OH/D concentration were determined between the bi-allelic combinations of rs228679 and rs228570. We detected statistically significant weak positive correlations between the AA (rs10741657 and rs228570) and TT (rs228679) and alleles and 25-OH/D and the probability of having higher 25-OH/D concentrations was 2- to 3-fold higher. However, the GG alleles of the 3 SNPs showed that the probability of having optimal 25-0H/D concentrations decreases by 32% for rs10741657, 38% for rs228679, and 74% for rs228570, showing a strong negative correlation between the degree of sarcopenia and 25-OH/D levels. Allelic variations in CYP2R1 (rs10741657), GC (rs2282679), and VDR (rs10741657) affect vitamin D levels and decisively influence the degree of sarcopenia in institutionalized elderly people.

Modulation of Plasma 25-Hydroxyvitamin D3 Level by Imatinib Mesylate in Patients with Chronic Myelogenous Leukemia: The Role of Uptake and Efflux Transporters.

Background: Vitamin D deficiency is a common side effect of imatinib mesylate (IM) therapy. Transporter polypeptides involved in the disposition of IM may be required for maintenance of adequate vitamin D concentrations. Objective: The aim of the present work is to study the association between the plasma concentrations of IM and plasma 25-hydroxyvitamin (25[OH]) D3 with transporter genotypes in patients with chronic myelogenous leukemia. Methods: A total of 77 adult patients with chronic myelogenous leukemia treated with IM participated in this study. Peak and trough plasma IM and 25(OH) vitamin D3 concentrations were measured and compared to the results of single nucleotide polymorphisms of the efflux transporting gene ABCB1-1236 C>T and the uptake transporting gene OATP1B3-334 T>G. Multiple linear regressions were used to examine the associations between 25(OH) vitamin D3 concentrations and a number of patient characteristics, including responses to therapy. Binary logistic regression analysis was used to predict odd ratios for the clinical response to IM. Results: Plasma 25(OH) vitamin D3 concentration quartile values were: 25%, 8.2 ng/mL; 50%, 9.8 ng/mL; and 75%, 12 ng/mL. High IM peak concentration, being OATP1B3-334 T>G (TT), and/ or ABCB1-1236 C>T (CT) are associated with lower concentrations of 25(OH) vitamin D3. Moreover, IM peak concentration, IM trough concentration, and plasma concentration of 25(OH) vitamin D3 were associated with the clinical response to IM. Conclusions: vitamin D, IM concentration, as well as the genotype of OATP1B3-334 T>G, had an influence on the response of patients with chronic myelogenous leukemia.

Vitamin D, oral health, and disease characteristics in juvenile idiopathic arthritis: a multicenter cross-sectional study.

BACKGROUND: Vitamin D deficiency has been associated with autoimmune diseases and oral health. Knowledge about the association between vitamin D status and oral conditions in JIA is limited. We aimed to investigate vitamin D status in a cohort of Norwegian children and adolescents with JIA and possible associations between serum vitamin D levels, clinical indicators of oral health, and JIA disease characteristics. METHODS: This multi-center, cross-sectional study, included individuals with JIA aged 4-16 years from three geographically spread regions in Norway. Demographic data, age at disease onset, disease duration, JIA category, disease status, medication, and vitamin D intake were registered. One blood sample per individual was analyzed for 25(OH) vitamin D, and the level of insufficiency was defined as < 50 nmol/L. A clinical oral examination was performed applying commonly used indices in epidemiological studies of dental caries, dental erosion, enamel defects, gingival bleeding, and oral hygiene. Serum vitamin D was used as exposure variable in multivariable regression analyses to estimate the associations between insufficient vitamin D level, JIA disease status, and oral conditions, with adjustments for age, sex, geographical region, BMI, seasonal blood sampling, and parental education. RESULTS: Among the 223 participants with JIA, 97.3% were Caucasians, 59.2% were girls, and median age was 12.6 years. Median disease duration was 4.6 years, and 44.4% had oligoarticular JIA. Mean serum vitamin D level was 61.4 nmol/L and 29.6% had insufficient levels. Vitamin D levels did not differ between sexes, but between regions, iso-BMI categories, age groups, and seasons for blood sampling. Insufficient vitamin D levels were associated with dentin caries (adjusted OR 2.89, 95% CI 1.43-5.86) and gingival bleeding (adjusted OR 2.36, 95% CI 1.10-5.01). No associations were found with active JIA disease or more severe disease characteristics. CONCLUSION: In our study, nearly 30% had vitamin D insufficiency, with a particularly high prevalence among adolescents. Vitamin D insufficiency was associated with dentin caries and gingival bleeding, but not with JIA disease activity. These results point to the need for a multidisciplinary approach in the follow-up of children with JIA, including an increased focus on vitamin D status and oral health.

Association of serum 25-OH-vitamin D level with FTO and IRX3 genes expression in obese and overweight boys with different FTO rs9930506 genotypes.

BACKGROUND: The roles of FTO gene and the level of serum 25-OH-vitamin D in obesity are frequently reported. This study aimed to investigate the interactions of serum 25-OH-vitamin D level, FTO and IRX3 genes expression, and FTO genotype in obese and overweight boys. METHODS: This study was carried out on the 120 male adolescents with overweight in Tehran, Iran. Blood samples were collected from the participants in order to evaluate the serum level of 25-OH-vitamin D, the expression level of FTO and IRX3 genes, and FTO genotype for rs9930506 at baseline and after 18 weeks of the study. RESULTS: In general, no significant association was found between serum 25-OH-vitamin D level and IRX3 and FTO genes expression. The results of linear regression on the relationship between 25-OH-vitamin D serum level and FTO and IRX3 genes expression based on FTO genotypes for rs9930506 indicated that in AA/AG genotype carriers, serum 25-OH-vitamin D level was positively associated with FTO gene expression (B = 0.07, p = 0.02) and inversely associated with IRX3 gene expression (B = - 0.07, p = 0.03). In GG carriers, serum 25-OH-vitamin D level was not associated with expression of IRX3 and FTO genes. CONCLUSION: There are significant interactions between 25-OH-vitamin D and the expression of FTO and IRX3 genes in the subset of obese patients with specific genotypes for FTO rs9930506. There was no association between serum 25-OH-vitamin D levels and the expression of FTO and IRX genes in individuals with a homozygous genotype for the risk allele of the FTO gene polymorphism.

The effect of umbilical cord blood spexin, free 25(OH) vitamin D3 and adipocytokine levels on intrauterine growth and anthropometric measurements in newborns.

Spexin is a newly described peptide and is known to reduce the uptake of long-chain fatty acids into adipocytes. The serum spexin levels of obese children between the ages of 12-18 are lower. The effect of serum spexin and free 25(OH) vitamin D3 levels on intrauterine development in newborns is unknown. Our aims is to evaluate the effects of spexin and adipocytokin levels in the cord blood of term newborn babies on the weight of the baby according to the gestation age (GA) and anthropometric measurement results. Babies who were born in our hospital and whose GA was ≥37 weeks were evaluated in three groups as appropriate for GA (AGA), small for GA (SGA) and large for GA (LGA). A total of 84 babies, including an equal number of infants in AGA, SGA and LGA groups, were included in the study. Spexin, leptin, active ghrelin, free 25(OH) vitamin D3, glucose, and insulin levels in the cord blood of infants were examined at birth. The results were compared according to GA and birth weight (BW). There was no statistically significant difference between groups in terms of mean spexin, active ghrelin, free 25(OH) vitamin D3, and insulin levels. The mean leptin level was significantly higher in LGA group than SGA and AGA groups (p 0.004). The mean spexin and leptin levels were higher in girls than in boys (respectively p value 0.029, 0.003). Although there is a significant positive correlation between BW, head circumference, height, umbilical circumference, umbilical circumference/height ratio and the mean leptin levels (p < 0.001), there was no significant correlation between mean spexin, active ghrelin, free 25 (OH) vitamin D3, insulin, and glucose levels. This study suggests that spexin may not have an effect on intrauterine development.

Cytokines, 25-OH vit D and disease activity in patients with juvenile-onset systemic lupus erythematosus.

BACKGROUND: Juvenile onset systemic lupus erythematosus JO-SLE patients usually exhibit a more aggressive disease course compared to adult patients. Vitamin D deficiency is proposed to be associated with increased disease activity and flares of numerous autoimmune diseases like SLE, rheumatoid arthritis, and scleroderma. OBJECTIVE: To evaluate the level of IL-17, IFN-γ, and 25-OH Vit D in JO-SLE patients versus healthy controls, and determine the correlation of those inflammatory mediators with SLE disease activity and damage scores. Furthermore, to analyze the relationship between 25-OH Vit D levels with the inflammatory cytokines (IFN-γ and IL-17) in JO-SLE patients. PATIENTS AND METHODS: Fifty JO-SLE patients and 25 controls were included in this study. Clinical and laboratory data of patients at the time of the study were recorded. SLE disease activity and damage were assessed using the SLEDAI-2K disease score and SLICC damage index, respectively. Plasma 25-OH Vit D, IFN-γ, and IL-17 concentrations were determined using the human ELISA kit. RESULTS: Plasma 25-OH Vit D levels (20 ng/mL) were significantly lower in JO-SLE patients compared to (31 ng/mL) controls (P = 0.014). Plasma levels of IFN-γ and IL-17 were significantly higher (163.5 and 25.5 pg./mL) in JO-SLE patients than (68.3 and 3 pg./mL) that of controls (P = 0.016 and P = 0.013). There was a significant negative correlation between 25-OH Vit D levels and SLEDAI-2K (R= -0.431) as well as IFN-γ (R= -0.471) plasma level (P = 0.022 and P = 0.027). CONCLUSION: IFN-γ and IL-17 were significantly higher in JO-SLE patients, while 25-OH Vit D was significantly lower compared to controls. There was a negative correlation between 25-OH Vit D and each of SLEDAI-2K and IFN-γ.

Reduced 25(OH) Vitamin D Association with Lower Alpha-1-Antitrypsin Blood Levels in Type 2 Diabetic Patients.

Introduction: Reduced circulating levels of 25(OH)VD are associated with an increased incidence of chronic lung diseases. Alpha-1-antitrypsin (AAT) is needed to maintain healthy lung function.Objective: This study examined the hypothesis that circulating levels of AAT are lower in adult type 2 diabetic patients and that a positive association exists between circulating AAT levels and 25(OH)VD levels in these patients.Methods: Fasting blood was obtained after written informed consent from type 2 diabetic patients (n = 80) and normal siblings or volunteers (n = 22) attending clinics at LSUHSC according to the protocol approved by the Institutional Review Board for Human studies. Plasma AAT and 25(OH)VD levels were determined using ELISA kits. HbA1c levels and chemistry profiles were analyzed at the clinical laboratory of LSUHSC hospital.Results: ATT and 25(OH)VD levels were significantly lower in type 2 diabetic patients compared with those of age-matched healthy controls. There was a significant positive correlation between 25(OH)VD and ATT deficiency. AAT levels showed significant positive correlation with HDL cholesterol levels in type 2 diabetic patients. There was no correlation between AAT levels and those of HbA1c or with the duration of diabetes of T2D patients.Conclusions: These results suggest that 25(OH)VD deficiency may predispose type 2 diabetic patients to AAT deficiency. Whether reduced levels of circulating AAT indeed contribute to the increased risk for lung dysfunction in subjects with type 2 diabetes needs further investigation.

A mendelian randomization study on causal effects of 25(OH)vitamin D levels on attention deficit/hyperactivity disorder.

BACKGROUND: While observational studies revealed an inverse association between serum 25(OH)vitamin D (25(OH)D) and the risk of attention deficit/hyperactivity disorder (ADHD), the causality of this relationship remains unclear. METHODS: We conducted a bidirectional two-sample Mendelian Randomization (MR) study to examine whether 25(OH)D has an effect on the risk to develop ADHD or vice versa. Information on single nucleotide polymorphisms (SNP) associated with serum 25(OH)D was obtained from a genome-wide association study (GWAS) considering phenotype data from 79,366 individuals of European ancestry. Data on risk for ADHD were derived from a GWAS analysis with 20,183 individuals diagnosed with ADHD and 35,191 controls. For our analysis, we considered effect sizes based on the European participants (19,099 cases and 34,194 controls). RESULTS: Single SNP analyses showed a causal effect of vitamin D on ADHD risk for only one SNP (rs12785878, p = 0.024). The overall MR estimates did not reveal a causal effect of 25(OH)D on risk for ADHD. In the reverse analysis, neither any single nor the multi-SNP MR analyses showed a causal effect of ADHD on 25(OH)D. CONCLUSION: Results from this two-sample MR study did not confirm a causal effect of 25(OH)D on ADHD or vice versa. Accordingly, our study does not provide evidence that improving 25(OH)D via supplementation could reduce the risk of developing ADHD.

Low serum 25-Hydroxy (OH) vitamin D levels are associated with increased arterial stiffness in healthy children: An echocardiographic study from Turkey.

OBJECTIVE: Arterial stiffness refers to arterial wall rigidity, particularly in central vessels, and is an independent predictor of cardiovascular disease in many chronic diseases. 25-Hydroxy (OH) vitamin D has beneficial effects on blood pressure, vascular endothelial function, and arterial stiffness; most importantly, its deficiency is common worldwide. Therefore, we aimed to elucidate the role of 25-OH vitamin D deficiency in arterial stiffness development and its relationship with arterial stiffness in healthy children. METHODS: This study included 80 patients with low levels of 25-OH vitamin D and 40 healthy control subjects. The study participants were then divided into three groups: group 1 consisted of patients with a deficient 25-OH D level of < 19.9 ng/ml, group 2 with an insufficient 25-OH D level between 20 and 29.9 ng/ml; group 3 were considered control group with a sufficient serum 25-OH vitamin D level of ≥30 ng/ml. Aortic strain, distensibility, stiffness index, and standard left ventricular measurements were calculated using M-mode echocardiographic data. RESULTS: Left ventricular mass index (LVMI) and inter-ventricular septal diastolic thickness (IVST) appeared to increase in group 1 compared to groups 2 and 3. Aortic strain and distensibility were significantly decreased in group 1, whereas aortic stiffness index and elastic modulus were significantly increased. The aortic stiffness index was negatively correlated with serum 25-OH vitamin D levels; however, aortic strain, aortic distensibility, and LVMI were positively correlated. CONCLUSIONS: Our study results revealed a significant relationship between 25-OH vitamin D levels indicative of a deficiency and aortic stiffness. Hence, we suggest that arterial stiffness may also occur in healthy children with a 25-OH vitamin D deficiency. Future in-depth studies are needed to understand the exact mechanisms underlying the aortic stiffness development associated with 25-OH vitamin D deficiency.

The association between preoperative 25-OH vitamin D levels and postoperative complications in patients undergoing colorectal cancer surgery.

BACKGROUND: Determining the modifiable risk factors for postoperative complications is particularly significant in patients undergoing colorectal surgery since those are associated with worse long-term outcomes. METHODS: Consecutive newly diagnosed 104 colorectal cancer patients were prospectively included in this single-center observational study. Preoperative serum 25-OH vitamin D levels were measured and analyzed for infectious and postoperative complications. RESULTS: Serum 25-OH vitamin D levels were found to be < 20 ng/ml in 74 patients (71.2%) and ≥ 20 ng/ml in 30 patients (28.8%); and the mean serum 25-OH vitamin D level was 15.95 (± 9.08) ng/ml. In patients with surgical site infection and infectious complications, 25-OH vitamin D levels were significantly lower than patients without complications (p = 0.036 and p = 0.026). However, no significant difference was demonstrated in 25-OH vitamin D levels according to overall postoperative complications. CONCLUSIONS: Our results suggest that vitamin D levels might be a potential risk factor for infectious complications in patients undergoing colorectal cancer surgery.

Correlation between maternal and neonatal blood Vitamin D level: Study from Pakistan.

In Pakistan, there is limited evidence for the levels and relationship of 25 (OH) Vitamin D (25(OH)D) status in pregnant women and their newborns, while the association between maternal 25(OH)D and newborn anthropometric measurements remains unexplored. Sociodemographic data were collected from 213 pregnant mothers during their visit to a tertiary care hospital at the time of childbirth. Anthropometric measurements were performed on all mothers and their newborns and blood samples collected from both for 25(OH)D levels. Participants were classified into two groups according to their 25(OH)D status: sufficient (25(OH)D ≥50 nmol L-1 ) and deficient (25(OH)D <50 nmol L-1 ). Simple and multiple regression models were used for analysis. Among 213 pregnant women, prevalence of 25(OH)D deficiency was 61.5%, and their newborn was 99.5% (mean 25(OH)D levels: 46.3 [11.3] and 24.9 [5.4] nmol L-1 , respectively). Maternal sociodemographic characteristics were similar between 25(OH)D deficient and sufficient mothers, whereas newborn 25(OH)D levels were significantly lower in the former (22.60 [4.53] vs. 27.67 [3.82] nmol L-1 , respectively, P < 0.001). There was a strong positive association between maternal and newborn 25(OH)D levels (r, 0.66; r2 , 43%, B [SE], 0.3 [0.02]; P < 0.001). Association of maternal 25(OH)D levels with newborn weight, length and head circumference was not significant (all P > 0.05). Our study shows a high prevalence of 25(OH)D deficiency in pregnant women and their newborns and a strong positive association between maternal and newborn 25(OH)D levels. Findings of this study indicate the importance of maintaining sufficient 25(OH)D levels during pregnancy.

Simultaneous measurement of 25(OH)-vitamin D and 24,25(OH)2-vitamin D to define cut-offs for CYP24A1 mutation and vitamin D deficiency in a population of 1200 young subjects.

Background Simultaneous measurement of 25(OH)D and 24,25(OH)2D is a new tool for predicting vitamin D deficiency and allows evaluating CYP24A1 lack of function. Interpretation of 24,25(OH)2D should be performed according to 25(OH)D levels and a ratio, called the vitamin D metabolite ratio (VMR) has been proposed for such a purpose. Unfortunately, the VMR can be expressed in different ways and cannot be used if 24,25(OH)2D concentrations are undetectable. Here, we propose evaluating the enzyme activity taking into consideration the probability that a normal population presents undetectable 24,25(OH)2D concentrations according to 25(OH)D levels. We thus retrospectively measured 25(OH)D and 24,25(OH)2D in a population of 1200 young subjects to evaluate the 25(OH)D threshold above which the enzyme was induced. Methods Serum samples from 1200 infants, children, adolescent and young adults were used to simultaneously quantify 25(OH)D and 24,25(OH)2D by LCMS/MS. Results Median (interquartile range [IQR]) levels were 20.6 (14.4-27.2) ng/mL for 25(OH)D. 172 subjects (14.3%) presented 24,25(OH)2D values below the LOQ. When 25(OH)D values were <11 ng/mL, 63.1% of subjects presented undetectable 24,25(OH)2D concentrations. Percentage decreased with increasing 25(OH)D values to become 19.7% for 25(OH)D comprised between 12 and 15 ng/mL, 5.1% for 25(OH)D between 16 and 20 and 0.7% for 25(OH)D >21 ng/mL. Conclusions We suggest using a statistical approach to evaluate CYP24A1 function according to 25(OH)D concentrations. Our results also show that vitamin D deficiency, as defined biochemically, could be around 20 ng/mL in infants, children, adolescent and young adults and that vitamin D deficiency could be evaluated on a more individual basis.

Vitamin D screening.

At present, there is no need and no sufficient evidence to support universal screening for vitamin D status. There are four categories of subjects in whom there is no requirement for screening, since a number of studies indicate beneficial effects of vitamin D supplementation; these are represented by children and adolescents, pregnant women, patients taking bone active drugs and subjects with documented hypovitaminosis D. In the remaining subjects, the utilization of adequate questionnaires will target with sufficient sensitivity and specificity those with hypovitaminosis D. These must be first supplemented and, at a later time, serum 25(OH)D assay should be requested to confirm attainment of sufficiency, independently of the threshold chosen. This strategy will cut costs deriving from both widespread use of vitamin D assays and vitamin D supplementation.