ABSTRACT The objective of this review was to investigate the effect of vitamin D3 supplementation on serum 25-hydroxyvitamin D concentration in individuals with single-nucleotide polymorphisms in the vitamin D receptor gene. The research was conducted on 241 articles found in the PubMed, Scopus, Science Direct, and Cochrane Library databases between November and December 2018. After article screening, three randomized double-blind placebo-controlled clinical trials were identified as eligible for this review. Participants were Australian, Brazilian, and Chinese individuals, who ingested doses of vitamin D3 ranging from 2000 IU to a megadose of 200,000 IU. The presence of the BB/Bb genotype of the BsmI polymorphism and the FokI G allele caused an increase in the serum concentrations of vitamin D after supplementation. Nonetheless, the few studies on this subject are not unanimous in their results. It is possible that differences among populations, sample sizes, doses, and time of supplementation have an impact on data and outcomes.

RESUMEN El objetivo de esta revisión fue investigar el efecto de la suplementación con vitamina D3 sobre la concentración sérica de 25-hidroxivitamina D en individuos con los polimorfismos de un solo nucleótido en el gen del receptor de la vitamina D. La investigación se realizó en 241 artículos encontrados en las bases de datos PubMed, Scopus, Science Direct y Cochrane Library entre noviembre y diciembre de 2018. Después de la selección del artículo, se identificaron tres ensayos clínicos aleatorios, controlados con placebo, doble ciego, como elegibles para esta revisión. Los participantes fueron australianos, brasileños y chinos, quienes ingirieron dosis de vitamina D3 que iban desde las 2000 UI hasta una megadosis de 200,000 UI. La presencia del genotipo BB / Bb del polimorfismo BsmI y el alelo FokI G causó un aumento en las concentraciones séricas de vitamina D después de la suplementación. No obstante, los pocos estudios sobre este tema no son unánimes en sus resultados. Es posible que las diferencias entre poblaciones, tamaños de muestra, dosis y tiempo de suplementación tengan un impacto en los datos y resultados de la investigación.

Abstract Evidence suggests that polymorphisms in the gene encoding a vitamin D receptor might affect blood pressure. The objective of this systematic review was to investigate the association between hypertension and vitamin D receptor (Fok I) gene polymorphism. A literature search was performed according to the PRISMA guidelines using the MEDLINE®/PubMed, Scopus, Cochrane Library CENTRAL, SciELO, and LILACS databases. The quality of case-control or cohort studies and studies based on cross-sectional methodology was evaluated using the Newcastle-Ottawa Scale and the protocol of Loney and coauthors [25], respectively. In this systematic literature search, 215 publications were identified, of which 10 were analyzed, including seven case-control studies, two cross-sectional studies, and one cohort study. The association between Fok I polymorphism and hypertension was reported in 60% of the publications and the risk for hypertension was shown to be related to FF and ff genotypes. In addition, Fok I polymorphism was shown to increase plasma renin activity, which plays an important role in regulating blood pressure. However, no association was observed between Fok I polymorphism and serum vitamin D levels. In conclusion, Fok I polymorphism plays an important role in hypertension.

Abstract Introduction: much evidence confirms that vitamin D may be associated with an improvement in CD4 cell counts in HIV-infected individuals, where antiretroviral therapy (ART) is used and associated with decreased 25(OH)D levels. Objective: to carry out a systematic review on the effect of vitamin D supplementation on HIV-infected adult patients. Methods: the research was conducted in the databases Science Direct, PubMed, BVS, Scielo Cochrane and Periods, from February to April 2018, with publication limit from 2000 to 2018, without restriction of gender, ethnicity and involving individuals with age older than 18 years. To evaluate the quality of the studies, we used the protocol Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) and the Jadad scale. Results: the search initially resulted in 198 articles. After the selection process 5 articles were identified as eligible, where they highlight that vitamin D supplementation may be an associated and effective intervention to reduce hypovitaminosis. ART reduces vitamin D3 levels and changes its metabolism, being associated with the risk of mortality. However, adequate levels of 25(OH)D are positively associated with the number of CD4 + cells and the reduction of infection levels. Conclusion: vitamin D supplementation promotes immune recovery. However, the cases analysed were few, insufficient to fully confirm the benefits and recommend supplementation. Therefore, intervention studies are needed to elucidate the role of vitamin D in human protection against HIV infections.

Resumen Introducción: muchas evidencias ratifican que la vitamina D puede estar asociada con la mejora de los niveles de células CD4 en individuos infectados por el VIH, tratados con terapia antirretroviral (ART) que se asocia a la disminución de los niveles de 25(OH)D. Objetivo: realizar una revisión sistemática sobre el efecto de la suplementación de vitamina D en pacientes adultos infectados con VIH. Métodos: la investigación fue realizada en las bases de datos Science Direct, PubMed, BVS, Scielo Cochrane y periódicos, de febrero a abril de 2018, con límite de publicación de 2000 a 2018, sin restricción de género, etnicidad y que involucra a individuos con edad mayores de 18 años. Para la evaluación de la calidad de los estudios, se utilizó el protocolo Preferred Reporting Items for Systematic Reviews y Meta-Analyzes (PRISMA) y la escala de Jadad. Resultados: la encuesta inicialmente resultó en 198 artículos. Después del proceso de selección, 5 artículos fueron identificados como elegibles, donde ponen de manifiesto que la suplementación con vitamina D puede ser una intervención asociada y eficaz para reducir la hipovitaminosis. La ART reduce niveles de la vitamina D3 y altera su metabolismo, estando asociada al riesgo de mortalidad. Sin embargo, los niveles adecuados de 25(OH)D están asociados positivamente al número de células CD4 + y la reducción de los niveles de infecciones. Conclusión: la suplementación de vitamina D promueve la recuperación inmunológica. Sin embargo, los casos analizados fueron pocos, insuficientes para confirmar totalmente los beneficios y recomendar la suplementación. Por lo tanto, estudios de intervención son necesarios para elucidar la actuación de la vitamina D en la protección humana contra las infecciones por el VIH.

Resumo O objetivo desta revisão sistemática foi analisar ensaios clínicos feitos na investigação do efeito da suplementação com vitamina D sobre o lúpus eritematoso sistêmico. A pesquisa foi feita nas bases de dados Scopus, PubMed e Biblioteca Cochrane, de agosto a setembro de 2016, sem limite de ano de publicação, restrição de gênero, idade e etnicidade. Para a questão norteadora foi empregada a estratégia Pico. Para avaliar a qualidade das publicações usaram-se o protocolo Prisma e a escala de Jadad. A análise do risco de viés dos ensaios clínicos ocorreu pela ferramenta de colaboração Cochrane. Após o processo de seleção e remoção de artigos duplicados, quatro artigos foram identificados como elegíveis. Os resultados de três estudos mostraram efeito positivo da suplementação na redução da atividade da doença e melhoria significativa nos níveis de marcadores inflamatórios, fadiga e função endotelial. Em apenas um estudo não houve melhoria na atividade da doença após a suplementação. Ademais, todos os estudos apresentaram aumento dos níveis séricos de vitamina D. Os dados desta revisão fornecem evidências dos benefícios da suplementação com vitamina D sobre o lúpus em pacientes com insuficiência/deficiência. Contudo, ainda é necessário elucidar a atuação do nutriente na proteção contra esse distúrbio metabólico, bem como a padronização do tipo, da dose e do tempo de suplementação com vitamina D.

Abstract The objective of this systematic review was to analyze clinical trials carried out for the investigation of the effect of vitamin D supplementation on systemic lupus erythematosus. The research was performed from August to September 2016, without limits regarding year of publication, restriction of gender, age, and ethnicity. For the guiding question, the PICO strategy was employed. To evaluate the quality of the publications the PRISMA protocol and Jadad scale were used. The risk of bias analysis of the clinical trials was performed using the Cochrane collaboration tool. After the process of article selection and removal of duplicates, four articles were identified as eligible. The results of three studies showed a positive effect of supplementation on disease activity reduction and significant improvement in levels of inflammatory markers, fatigue, and endothelial function. Only one study showed no improvement in disease activity after supplementation. Moreover, all studies showed an increase in serum vitamin D levels. The data from this review provide evidence on the benefits of vitamin D supplementation in patients with lupus and vitamin D insufficiency/deficiency. However, it is still necessary to elucidate whether vitamin D acts in the protection against this metabolic disorder, as well as the standardization of the type, dose and time of vitamin D supplementation.