Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Vitamin D Serum Concentrations and COVID-19
Active vitamin D [1,25(OH)2D3—calcitriol] is a secosteroid hormone whose receptor is expressed on all cells of the immune system. Vitamin D has a global anti-inflammatory effect and its role in the management of a SARS-CoV-2 infection has been investigated since the beginning of the COVID-19 pandemic.
  • 306
  • 23 Nov 2022
Topic Review
Vitamin D Scarcity in Arctic and  Tropical Peoples
Vitamin D metabolism differs among human populations because the species has adapted to different natural and cultural environments. Two environments are particularly difficult for the production of vitamin D by the skin: the Arctic, where the skin receives little solar UVB over the year; and the Tropics, where the skin is highly melanized and blocks UVB. In both cases, natural selection has favored the survival of those individuals who use vitamin D more efficiently or have some kind of workaround that ensures sufficient uptake of calcium and other essential minerals from food passing through the intestines. Vitamin D scarcity has either cultural or genetic solutions. Cultural solutions include consumption of meat in a raw or boiled state and extended breastfeeding of children. Genetic solutions include higher uptake of calcium from the intestines, higher rate of conversion of vitamin D to its most active form, stronger binding of vitamin D to carrier proteins in the bloodstream, and greater use of alternative metabolic pathways for calcium uptake. Because their bodies use vitamin D more sparingly, indigenous Arctic and Tropical peoples can be misdiagnosed with vitamin D deficiency and wrongly prescribed dietary supplements that may push their vitamin D level over the threshold of toxicity.
  • 1.3K
  • 20 Oct 2022
Topic Review
Vitamin D on Skin Aging
The normal vitamin D3 status is important for a general prevention of premature aging maintaining a healthful skin aging. Vitamin D3metabolites including its classical (1,25(OH)2D3) and novel (CYP11A1-intitated) D3hydroxyderivatives exert many beneficial protective effects on the skin, which could influence the process of premature aging via many different mechanisms, leading to a delay or attenuation of both chronological skin aging and photoaging. Skin-resident cells (keratinocytes, fibroblasts, and sebocytes) are capable of locally activating vitamin D3and exhibiting a diverse biological effect such as photoprotection and immunosuppression, similar to the UVR-induced one.
  • 753
  • 29 Sep 2021
Topic Review
Vitamin D on Skeletal Muscle Dysfunction with COPD
Skeletal muscle dysfunction is frequently associated with chronic obstructive pulmonary disease (COPD), which is characterized by a permanent airflow limitation, with a worsening respiratory disorder during disease evolution. COPD is a progressive lung disease, characterized by an irreversible airflow limitation. In COPD, the pathophysiological changes related to the chronic inflammatory state affect oxidant–antioxidant balance, which is one of the main mechanisms accompanying extra-pulmonary comorbidity such as muscle wasting. Muscle impairment is characterized by alterations on muscle fiber architecture, contractile protein integrity, and mitochondrial dysfunction. Vitamin D deficiency affects oxidative stress and mitochondrial function influencing disease course through an effect on muscle function in COPD patients.
  • 531
  • 27 Apr 2022
Topic Review
Vitamin D on Immune System
Vitamin D deficiency, which causes an imbalance in bone remodeling, is a global public health problem and its frequency is increasing.
  • 541
  • 06 Dec 2021
Topic Review
Vitamin D Metabolism in Celiac Disease
Celiac disease is a chronic autoimmune disorder involving the small intestine, characterized by villous atrophy, crypt hyperplasia and an increase in intraepithelial lymphocytes. Due to both calcium malabsorption and immune activation, a high prevalence of bone mass derangement is evident in this condition, regardless of the presence of overt malabsorption. In untreated patients, secondary hyperparathyroidism is responsible for the hyperconversion of 25-vitamin D into 1,25-vitamin D making mandatory the determination of serum levels of both vitamin metabolites to avoid a wrong diagnosis of vitamin D deficit. A gluten-free diet allows for a normalization of bone and mineral metabolism, reverting these abnormalities and raising some doubts on the need for vitamin supplementation in all the patients. 
  • 668
  • 19 Jan 2023
Topic Review
Vitamin D Metabolism Gene Polymorphisms
Vitamin D is a potent immunonutrient that through its main metabolite calcitriol, regulates the immunomodulation of macrophages, dendritic cells, T and B lymphocytes, which express the vitamin D receptor (VDR), and they produce and respond to calcitriol. Genetic association studies have shown that up to 65% of vitamin D serum variance may be explained due to genetic background. 
  • 2.3K
  • 01 Jan 2022
Topic Review
Vitamin D May Protect against Breast Cancer
In general, the protective effect of vitamin D3 against breast cancer is underlined by inhibition of proliferation and migration, stimulation of differentiation and apoptosis, and inhibition of epithelial/mesenchymal transition in breast cells. Vitamin D3 may also inhibit the transformation of normal mammary progenitors into breast cancer stem cells that initiate and sustain the growth of breast tumors. As long noncoding RNAs (lncRNAs) play an important role in breast cancer pathogenesis, and the specific mechanisms underlying this role are poorly understood, we provided several arguments that vitamin D3/VDR may induce protective effects in breast cancer through modulation of lncRNAs that are important for breast cancer pathogenesis.
  • 530
  • 01 Apr 2022
Topic Review
Vitamin D in Toxins and Aging-Related Compounds Neutralisation
Vitamin D is a micronutrient that is metabolised into a multifunctional secosteroid compound, calcitriol [1,25(OH)2D], essential for the health and survival of humans. Both 25 dihydroxy vitamin D [25(OH)2D: calcifediol] and its hormonal form, 1,25-dihydroxyvitamin D [1,25(OH)2D: calcitriol] are essential for human physiological functions, including damping down inflammation and the excessive intracellular oxidative stresses. The interaction of 1,25(OH)2D with its intracellular (calcitriol)receptors modulates vitamin D–dependent gene transcription and activation of vitamin D-responsive elements, which triggers multiple second messenger systems. Vitamin D controls systemic inflammation, oxidative stress, and mitochondrial respiratory function. Molecular and cellular actions of calcitriol slow down oxidative stress and inflammation, cell and tissue damage, and the aging process, especially when the circulating 25(OH)D concentration is maintained above 50 ng/mL. Whereas, Vitamin D deficiency impairs mitochondrial functions and enhances oxidative stress and systemic inflammation, increases infection-related complications, premature deaths, and accelerates the aging process.  
  • 546
  • 20 Jun 2022
Topic Review
Vitamin D in the Context of Evolution
For at least 1.2 billion years, eukaryotes have been able to synthesize sterols and, therefore, can produce vitamin D when exposed to UV-B. Vitamin D endocrinology was established some 550 million years ago in animals, when the high-affinity nuclear receptor VDR (vitamin D receptor), transport proteins and enzymes for vitamin D metabolism evolved. This enabled vitamin D to regulate, via its target genes, physiological process, the first of which were detoxification and energy metabolism. In this way, vitamin D was enabled to modulate the energy-consuming processes of the innate immune system in its fight against microbes. In the evolving adaptive immune system, vitamin D started to act as a negative regulator of growth, which prevents overboarding reactions of T cells in the context of autoimmune diseases. When, some 400 million years ago, species left the ocean and were exposed to gravitation, vitamin D endocrinology took over the additional role as a major regulator of calcium homeostasis, being important for a stable skeleton.
  • 366
  • 29 Jul 2022
  • Page
  • of
  • 5495
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback