Comparative analysis of the association between various serum vitamin D biomarkers and sarcopenia.

BACKGROUND: Vitamin D status is associated with muscle strength and maintenance of muscle fibers. However, which serum vitamin D biomarker better reflects sarcopenia remains unclear. The aim of this study was to investigate associations between various serum vitamin D biomarkers (total 25-hydroxy vitamin D [25(OH)D], bioavailable 25(OH)D, 24,25-dihydroxyvitamin D [24,25(OH)2 D], and vitamin D metabolite ratio [VMR]) and sarcopenia. METHODS: The data for 83 hip fracture patients were finally included in the analysis. Sarcopenia was defined according to the Asia Working Group for Sarcopenia (AWGS) criteria. Measurements of 24,25(OH)2 D and 25(OH)D were made using solid-phase extraction (SPE) and subsequent liquid chromatography-tandem mass spectrometry (LC-MS/MS). Vitamin D binding protein (VDBP) concentration was measured using an enzyme-linked immunosorbent assay. The VMR was calculated by dividing serum 24,25(OH)2 D by serum 25(OH)D and then multiplying by 100. Based on total 25(OH)D, VDBP, and albumin concentrations, bioavailable 25(OH)D concentrations were calculated using the equations from the other previous studies. RESULTS: Bioavailable 25(OH)D levels were significantly (p = 0.030) decreased in the sarcopenia group compared with the non-sarcopenia group. Results of ROC analysis for the diagnosis of sarcopenia using serum level of bioavailable of 25(OH)D revealed that the cutoff point for bioavailable 25(OH)D was 1.70 ng/ml (AUC = 0.649, p < 0.001). In the group with a bioavailable 25(OH)D less than 1.70 ng/ml, the incidence of sarcopenia increased by 3.3 times (odds ratio: 3.33, p = 0.013). CONCLUSION: We demonstrated that bioavailable 25(OH)D was associated with sarcopenia among the various serum vitamin D biomarkers. Bioavailable vitamin D might be helpful for assessing the risk of sarcopenia.

Uptake of Vitamins D2, D3, D4, D5, D6, and D7 Solubilized in Mixed Micelles by Human Intestinal Cells, Caco-2, an Enhancing Effect of Lysophosphatidylcholine on the Cellular Uptake, and Estimation of Vitamins D' Biological Activities.

Vitamins D have various biological activities, as well as intestinal calcium absorption. There has been recent concern about insufficient vitamin D intake. In addition to vitamins D2 and D3, there are lesser-known vitamins D4-D7. We synthesized vitamins D5-D7, which are not commercially available, and then evaluated and compared the mixed micelles-solubilized vitamins D uptake by Caco-2 cells. Except for vitamin D5, the uptake amounts of vitamins D4-D7 by differentiated Caco-2 cells were similar to those of vitamins D2 and D3. The facilitative diffusion rate in the ezetimibe inhibited pathway was approximately 20% for each vitamin D type, suggesting that they would pass through the pathway at a similar rate. Lysophosphatidylcholine enhanced each vitamin D uptake by approximately 2.5-fold. Lysophosphatidylcholine showed an enhancing effect on vitamin D uptake by reducing the intercellular barrier formation of Caco-2 cells by reducing cellular cholesterol, suggesting that increasing the uptakes of vitamins D and/or co-ingesting them with lysophosphatidylcholine, would improve vitamin D insufficiency. The various biological activities in the activated form of vitamins D4-D7 were estimated by Prediction of Activity Spectra for Substances (PASS) online simulation. These may have some biological activities, supporting the potential as nutritional components.

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Vitamin D supplementation during pregnancy: Improvements in birth outcomes and complications through direct genomic alteration.

Pregnancy represents a time of rapid change, including dramatic shifts in vitamin D metabolism. Circulating concentrations of the active form of vitamin D-1,25(OH)2D skyrocket early in pregnancy to levels that would be toxic to a nonpregnant adult, signaling a decoupling of vitamin D from the classic endocrine calcium metabolic pathway, likely serving an immunomodulatory function in the mother and her developing fetus. In this review, we summarize the unique aspects of vitamin D metabolism and the data surrounding vitamin D requirements during this important period. Both observational and clinical trials are reviewed in the context of vitamin D's health effects during pregnancy that include preeclampsia, preterm birth, and later disease states such as asthma and multiple sclerosis. With enhanced knowledge about vitamin D's role as a preprohormone, it is clear that recommendations about supplementation must mirror what is clinically relevant and evidence-based. Future research that focuses on the critical period(s) leading up to conception and during pregnancy to correct deficiency or maintain optimal vitamin D status remains to be studied. In addition, what effects vitamin D has on genetic signatures that minimize the risk to the mother and her developing fetus have not been elucidated. Clearly, while there is much more research that needs to be performed, our understanding of vitamin D requirements during pregnancy has advanced significantly during the last few decades.

Cálcio e a regulação da adiposidade e do peso corporal / Calcium and the regulation of adiposity and body weight

Obesity is known to be an evolving pandemic and adequate nutrition is one of the major cornerstones of its treatment and prevention. However, not only the role of energy partitioning and macronutrient distribution, but also the influence of micronutrients on the control of body weight and adiposity have been recently discussed. In this regard, calcium has received a great deal of attention by the scientific community. Several studies using both animal and human models (observational and randomly controlled trials) have focused on the effects of calcium on obesity, showing controversial results. Several factors seem to influence the results obtained, and although a definite conclusion is still unclear, the literature points towards an interesting positive effect of the increased intake of dietary calcium (particularly from dairy sources) on the regulation of body weight and adiposity in the overweight and obese population undergoing restrictive energy intake.

Se sabe que la obesidad es una pandemia en evolución. La dieta adecuada se ha constituido en uno de los pilares para su tratamiento y prevención.Sin embargo, recientemente, se ha discutido no sólo el papel de la restricción calórica y distribución de macronutrientes, sino, también, la influencia de los micronutrientes sobre el control del peso corporal y la adiposidad. En este sentido, el calcio ha recibido una atención especialpor parte de la comunidad científica. Diversos estudios, tanto los realizados con animales como con seres humanos, en ensayos clínicosaleatorizados y en modelos observacionales, se han centrado en esta temática, con resultados controvertidos. Varios factores parecen influiren los resultados obtenidos, y, aunque no haya una conclusión definitiva sobre el tema, la literatura señala un interesante efecto beneficiosoen el aumento de la ingesta de calcio (especialmente cuando proviene de los lácteos) sobre el control de la adiposidad y del peso corporal deindividuos con sobrepeso y obesidad sometidos a la dieta restrictiva.

A obesidade é, sabidamente, uma pandemia em evolução. A dieta adequada tem se constituído em um dos pilares no seu tratamento e na suaprevenção. Contudo, recentemente, tem sido discutido o papel não só da restrição calórica e da distribuição dos macronutrientes, mas, também, a influência dos micronutrientes sobre o controle da adiposidade e do peso corporal. Neste sentido, o cálcio tem recebido especial atenção da comunidade científica. Diversos estudos ? tanto com modelo animal quanto a partir da experimentação com humanos em modelos observacionais e em estudos clínicos controlados ? têm se debruçado sobre esta temática, com resultados controversos. Vários fatores parecem influenciar os resultados obtidos e, embora uma conclusão definitiva acerca do tema ainda não seja clara, a literatura aponta para um interessante efeito benéfico do aumentodo consumo de cálcio dietético (principalmente quando oriundo dos laticínios) sobre o controle da adiposidade e do peso corporal de indivíduoscom sobrepeso e obesidade submetidos à dieta restritiva.

Epstein-Barr virus antibodies and vitamin D in prospective multiple sclerosis biobank samples.

BACKGROUND: The antibody reactivity against Epstein-Barr nuclear antigen-1 (EBNA-1), and 25-hydroxyvitamin D (25(OH)D) status have been associated with multiple sclerosis (MS) risk. Interaction between these two factors has been proposed. OBJECTIVES: The objective of this paper is to examine the association between antibody reactivity against EBNA-1 and five EBNA-1 domains, and the risk of MS, and to examine if these antibodies and 25(OH)D status interact regarding MS risk in prospectively collected blood samples. METHODS: Antibody reactivity and 25(OH)D levels were measured using ELISAs in n = 192 MS cases and n = 384 matched controls. The risk of MS was analysed using matched logistic regression. Interaction on the additive scale was assessed. RESULTS: The risk of MS increased across tertiles of antibody reactivity against EBNA-1, domain EBNA-1(402-502), and domain EBNA-1(385-420); p trends < 0.001. In young individuals (below median age at sampling, < 26.4 years), these associations were stronger, and 25(OH)D levels correlated inversely to antibody reactivity against EBNA-1 and the EBNA-1 domains. No statistical interaction was found. CONCLUSIONS: We confirm that increased antibody reactivity against EBNA-1 is a risk factor of MS. 25(OH)D status might influence the immune response towards Epstein-Barr virus in young subjects, and thereby modulate MS risk.

Vitamin D therapy in cardiac hypertrophy and heart failure.

Vitamin D3 is made in the skin, modified in the liver to form 25(OH)D, and then further hydroxylated in the kidney to form the active hormone, 1,25-dihydroxyvitamin D3 (calcitriol). Calcitriol binds to and activates the vitamin D receptor (VDR), a nuclear receptor, to regulate numerous downstream signaling pathways in different cells and tissues. Emerging evidence suggests that VDR plays an important role in modulating cardiovascular, immunological, metabolic and other functions. Data from preclinical, epidemiological and clinical studies have shown that deficiency in VDR activation is associated with an increased risk for cardiovascular disease (CVD). Results from interventional trials using either nutritional vitamin D or VDR agonists (VDRAs) support the idea that VDR activation is beneficial for improving the underlying factors of CVD such as hypertension, endothelial dysfunction, atherosclerosis, vascular calcification, cardiac hypertrophy and progressive renal dysfunction. Furthermore, a majority of chronic kidney disease (CKD) patients die of CVD and VDRA therapy is associated with a survival benefit in both pre-dialysis and dialysis CKD patients. Most of the studies measured serum 25(OH)D as an indication for vitamin D deficiency, which does not truly reflect the VDR activation status. Although VDR plays an important role in regulating cardiovascular function and VDRAs may be potentially useful for treating CVD, at present VDRAs are not indicated for the treatment of CVD.

[Vitamin D therapy in renal osteodystrophy].

In Japan, three oral preparations (calcitriol, alfacalcidol and falecalcitriol) and two intravenous preparations (calcitriol and maxacalcitol) are now available for the vitamin D(3) therapy in renal osteodystrophy. In general, oral therapy is indicated for mild cases of secondary hyperparathyroidism (intact PTH<300 pg/mL) to maintain adequate level of serum PTH except "calcitriol oral pulse therapy" for moderate to severe cases. Recently, intravenous therapy has been introduced to treat more severe cases by using the advantage of rapid clearance of these metabolites. In order to use these preparations safely, adequate level of both serum intact PTH (150-300 pg/mL) and Ca/P product (<55) should be maintained to prevent from adynamic bone and vascular calcification.

Medical devices; reclassification and codification of vitamin D test system--FDA. Final rule.

The Food and Drug Administration (FDA) is announcing that it has issued an order in the form of a letter to INCSTAR Corp. reclassifying INCSTAR 25-Hydroxyvitamin D 125I Radioimmunoassay (RIA). This radioimmunoassay device is intended for use in clinical laboratories for the quantitative determination of 25-hydroxyvitamin D (25-OH-D) and other hydroxylated metabolites of vitamin D in serum or plasma to be used in the assessment of vitamin D sufficiency. The device and substantially equivalent devices of this generic type were reclassified from class III (premarket approval) to class II (special controls). Accordingly, the order is being codified in the Code of Federal Regulations.