Importancia de la Vitamina D en la época del COVID-19 / Importance of Vitamin D in the time of COVID-19

"Los coronavirus pertenecen a una gran familia de virus (Coronaviridae) que infectan aves y varios mamíferos. El coronavirus actualmente denominado SARS-CoV-2, fue descubierto en diciembre de 2019 en Wuhan, provincia de Hubei, China, y es el agente causal de la epidemia de neumonía atípica actual" (COVID-19; Coronavirus Disease 2019). Los casos más graves presentan un síndrome de dificultad respiratoria aguda que puede conducir a la muerte. La vitamina D (VD), además del efecto bien conocido y positivo sobre la salud ósea y la homeostasis del calcio, tiene efecto pleiotrópico en varios órganos, con distribución casi universal del receptor de VD y de las enzimas de metabolización de 25 hidroxivitamina D (25OHD) en las células del organismo. Estas acciones extraesqueléticas dependen de la síntesis en dichas células del metabolito activo 1,25 dihidroxivitamina D por regulación paracrina y autocrina, dependiente de niveles circulantes óptimos de 25OHD. Por sus acciones inmunomoduladora, antiinflamatoria, antimicrobiana, reguladora del sistema renina-angiotensina-aldosterona, favorecedora de la indemnidad del epitelio respiratorio y la homeostasis redox celular, la VD podría tener efecto protector en la infección por COVID-19. Entre los grupos de riesgo para COVID-19 figuran los adultos mayores, obesos, diabéticos, hipertensos, con afecciones cardiovasculares, patologías con mayor incidencia en individuos con hipovitaminosis VD. La suplementación con VD, para alcanzar niveles óptimos de 25OHD de 40-60 ng/ml, podría reducir la incidencia, severidad y riesgo de muerte en la actual pandemia por COVID-19, como medida complementaria mientras se desarrollan la vacuna y otras medicaciones específicas. (AU)

Coronaviruses belong to a large family of viruses (Coronaviridae) that infect birds and various mammals. The novel coronavirus currently known as SARS-CoV-2 was discovered in December 2019 in Wuhan, Hubei province, China and is the causal agent of the current atypical pneumonia epidemic (COVID-19: Coronavirus Disease 2019); The most severe cases present with acute respiratory distress syndrome that can lead to death. Vitamin D (VD) has a pleiotropic effect on several organs, in addition to its wellknown and positive effect on bone health and calcium homeostasis, with an almost universal distribution of the VD receptor and the metabolites of 25hydroxyvitamin D (25OHD) in all cells of the body. These extra-skeletal actions depend on the synthesis of the active metabolite 1,25dihydroxyvitamin D in the cells depending on the optimal circulating levels of 25OHD and though paracrine and autocrine regulation. Due to its immunomodulatory, anti-inflammatory, antimicrobial, and regulatory actions on the renin angiotensin aldosterone system, which favors the compensation of the respiratory epithelium and cellular redox homeostasis, the VD could have a protective effect on COVID-19 infection. Among the risk groups for COVID-19 are obese, diabetic, and hypertensive patients, subjects with cardiovascular conditions, and elderly people. All these pathologies show a higher incidence in individuals with VD hypovitaminosis. VD supplementation, to achieve optimal 25OHD levels of 40-60 ng/ml, could reduce the incidence, severity, and risk of death in the current COVID-19 pandemic, as a complementary measure while the vaccine and other specific therapies are being developed. (AU)

Hypovitaminosis D in patients with Crohn's disease / Hipovitaminose D em pacientes portadores da doença de Crohn

Objective: Vitamin D has been widely studied as a mediator of the immune response, becoming evident the prevalence of hypovitaminosis D in patients with Crohn's disease. This work aims at evaluating the serum levels of vitamin D in patients suffering from Crohn's disease in a southeast region of Brazil. Methods: It is a prospective study, with statistical analysis of the values of serum vitamin D measured between April 2014 and April 2015 in patients with Crohn's disease. Individuals with mild anal complaints, without any colorectal involvement, comprised the control group. Results: One hundred and four patients whose average age was 40.6 years were evaluated, being 56 (53.8%) female and 48 (46.2%) male. The average serum vitamin D level was 21.6 ng/mL, with standard deviation 13.85. The control group was comprised by 66 individuals, whose average age was 48.9 years. With 38 (57.6%) female and 28 (42.4%) male. In this group the average serum vitamin D level was 40.9 ng/mL. Statistical significance was demonstrated with p<0.0001. Conclusion: There was high prevalence of hypovitaminosis D in patients with Chron's disease, when compared to the control group. Hypovitaminosis D was not evidenced in patients in the latter group.

Objetivo: A vitamina D tem sido amplamente estudada como mediadora da resposta imune, tornando-se evidente a prevalência de hipovitaminose D em pacientes com doença de Crohn. Este trabalho objetiva avaliar os níveis séricos de vitamina D nos pacientes com portadores de doença de Crohn em uma região do sudeste do Brasil. Métodos: Trata-se de estudo prospectivo, com análise estatística dos valores da vitamina D sérica dosados entre Abril de 2014 e Abril de 2015 em pacientes com doença de Crohn. Indivíduos com queixas anais leves, sem qualquer acometimento colorretal, compuseram o grupo controle. Resultados: Foram avaliados 104 pacientes, cuja média de idade foi de 40,6 anos, sendo 56 (53,8%) mulheres e 48 (46,2%) homens. O nível sérico de vitamina D médio foi 21,6 ng/mL, com desvio-padrão de 13,85. O grupo controle foi composto por 66 indivíduos, cuja média de idade foi 48,9 anos, com 38 (57,6%) mulheres e 28 (42,4%) homens. Neste grupo o nível sérico médio de vitamina D foi 40,9 ng/mL. Foi demonstrada significância estatística com p<0,0001. Conclusão: Houve elevada prevalência de hipovitaminose D em pacientes com doença de Crohn, quando comparados ao grupo controle. Não foi evidenciada hipovitaminose D entre os pacientes deste último grupo.

Influência da suplementação de vitaminas A, D e E na função imune de bezerros alimentados com dieta á base de feno capim tifton (cynodon spp) / Influence of A, D and E vitamin supplements on immune function of calves fed diet tifton (cynodon spp) hay

As vitaminas são compostos orgânicos necessários em poucas quantidades no organismo, todavia indispensáveis para as funções metabólicas. Elas se inserem em inúmeras reações metabólicas, fisiológicas e imunes das células, necessárias para a manutenção da saúde animal, além de atuarem como imunoestimulante. Embora a dieta rica em folhagens verdes frescas forneça quantidades suficientes de vitaminas A, D e E a suplementação intensiva com alimentos conservados na forma de feno ou silagem pode reduzir em até 50 % dos teores destas vitaminas no alimento. Diante disso, a proposta do trabalho foi verificar se a administração parenteral de vitaminas A, D e E age como imunoestimulante em garrotes estabulados e alimentados exclusivamente com feno de tifton. Para tanto 14 bovinos foram divididos em dois grupos homogêneos, sendo o grupo S, suplementado com vitamina A, D e E em dose única de 30 mL por via intramuscular; e o grupo C, sem suplementação. Ambos os grupos foram alojados em baias parcialmente privadas de sol, e alimentados com feno por um período de três meses. A avaliação imune foi realizada por hemogramas e ensaio de função leucocitária (metabolismo oxidativo e fagocitose) nos momentos antes do tratamento, três e dez dias após os tratamentos. Tendo em vista que a suplementação com polivitamínicos A, D e E aumentou a porcentagem da atividade de células granulocítica e a intensidade da atividade de células mononucleares, além de intensificar o efeito antioxidante prolongando a sobrevida de hemácias e neutrófilos, conclui-se que esta suplementação promoveu efeito benéfico na resposta imune de bezerros da Raça Holandesa, apesar dos efeitos deletérios da alimentação exclusiva com feno e da privação parcial da incidência solar direta.

Vitamins are organic compounds which are required in small quantities in the body, however essential for the metabolic functions. They participate in numerous metabolic reactions, physiological and immune cells, needed to maintain animal health, as well as act as immunostimulants. Although the diet rich in fresh green foliage provides sufficient amounts of vitamin A, D and E, intensive supplementation with food stored in the form of hay or silage can reduce up to 50% of the levels of these vitamins in food. Given this, the proposal of this study was to verify how the parenteral administration of vitamins ADE acts as immunostimulant in steers fed exclusively with hay of tifton. For that, 14 cattle were divided into two homogeneous groups: Group S, supplemented with vitamin A, D e E given in a single intramuscular dose of 30mL, and Group C without supplementation. Both groups were housed in private stalls and fed with hay for a period of three months. Immune evaluation was performed by blood count and testing of leukocyte function (oxidative metabolism and phagocytosis) in the moments before treatment, three and ten days after the treatments. Considering that supplementation with vitamin A, D e E increased the percentage of granulocytic cell activity and the intensity of the activity of mononuclear cells, as well as intensified the antioxidant effect prolonging the survival of red blood cells and neutrophils, it can be concluded that this treatment had a beneficial effect on the immune response of Holstein calves, despite the damaging effects of exclusive feeding hay, and the partially deprivation of solar incidence.

Vitamina D y asma: artículo de revisión / Vitamin D and asthma, a review

En los últimos 40 años se ha observado una disminución progresiva de los niveles de vitamina D en la población, debido en parte a cambios en los estilos de vida. Bajos niveles vitamina D se han asociado a aumento de varias enfermedades incluyendo el asma bronquial. De acuerdo a la literatura disponible en niños, se ha observado que niveles bajos de vitamina D se correlacionan con aumento de la hiperreactividad bronquial y atopia. En niños con diagnóstico establecido de asma bronquial, bajos niveles de vitamina D se asocian a evolución más severa, incluyendo mayor número de consultas a Servicio de Urgencia y hospitalizaciones, baja función pulmonar, mayor uso de corticoides inhalados y sistémicos y exacerbaciones más frecuentes y severas. La acción de la vitamina D en el asma bronquial estaría dada por su papel inmunomodulatorio sobre las células del sistema inmune, inhibiendo citokinas del tipo Th2, inhibiendo la secreción de IL lly estimulando la de IL10. Estudios in vitro sugieren además que la vitamina D tendría cierto papel en revertir la corticoresistencia y la remodelación de la vía aérea.

In the last 40 years a progresive decrease of vitamin D levels has been observed in the population due to changes in lifestyles. Low levels of vitamin D have been associated with several diseases, including asthma. Recent studies have shown that low levels of vitamin D in children are correlated with an increase in bronchial reactivity and atopia. In children with an established diagnosis of asthma, low levels of vitamin D is associated with a more severe evolution of asthma, including increased numbers of emergency room visits and hospital admissions, low lung function, increased use of inhaled and systemic corticosteroids and more frequent and severe exacerbations. The role of vitamin D on bronquial asthma is its immunomodulatory action upon the cells of the immune system, inhibiting Th2 type cytokines and ILll secretion and stimulating IL 10 secretion. In vitro studies suggest a posible role of vitamin D in reverting steroid resistance and airways remodeling.

Vitamina D: infecciones, atopia y asma / Vitamin D: infections, atopy and asthma

Data on vitamin D insufficiency are expanding to include evidence on its role in asthma, allergic disorders, and atopic dermatitis, vitamin D is now recognized as an immunomodulator. In addition epidemiologic studies have identified a link between inadequate vitamin D concentrations and infectious disease. Furthermore, their contribution in host defense against infection has been elucidated. Vitamin D plays an important role in innate and adaptive immune response. Several clinical studies exist supporting a relationship between vitamin D status and atopic dermatitis, asthma, asthma exacerbations, pulmonary function. The effect of vitamin D supplementation is still being studied and may be a promise.

La información sobre la deficiencia de vitamina D y su rol en el asma, desordenes alérgicos y dermatitis atópica, está en aumento. Además estudios epidemiológicos han identificado la relación entre concentraciones inadecuadas de vitamina D y enfermedades infecciosas. Su contribución a la inmunidad ha sido aclarada. La vitamina D juega un importante rol en la inmunidad innata y adaptativa y se le reconoce una acción inmunomoduladora. Varios estudios clínicos confirman que su status se relaciona con Dermatitis Atópica, Asma, exacerbaciones asmáticas y función pulmonar. El efecto de la suplementación con vitamina D esta aun en investigación y constituye una promesa.