-
Nutrients Jul 2022Vitamin A is a fat-soluble micronutrient necessary for the growth of healthy skin and hair. However, both too little and too much vitamin A has deleterious effects.... (Review)
Review
Vitamin A is a fat-soluble micronutrient necessary for the growth of healthy skin and hair. However, both too little and too much vitamin A has deleterious effects. Retinoic acid and retinal are the main active metabolites of vitamin A. Retinoic acid dose-dependently regulates hair follicle stem cells, influencing the functioning of the hair cycle, wound healing, and melanocyte stem cells. Retinoic acid also influences melanocyte differentiation and proliferation in a dose-dependent and temporal manner. Levels of retinoids decline when exposed to ultraviolet irradiation in the skin. Retinal is necessary for the phototransduction cascade that initiates melanogenesis but the source of that retinal is currently unknown. This review discusses new research on retinoids and their effects on the skin and hair.
Topics: Hair; Retinoids; Skin; Tretinoin; Vitamin A
PubMed: 35889909
DOI: 10.3390/nu14142952 -
Nutrition in Clinical Practice :... Dec 2019Vitamin A is a general term for retinoids. Vitamin A deficiency leads to a variety of cutaneous manifestations. It also functions as a hormone through retinoic acid... (Review)
Review
Vitamin A is a general term for retinoids. Vitamin A deficiency leads to a variety of cutaneous manifestations. It also functions as a hormone through retinoic acid receptors altering the activity of multiple cell lines. Pancreatic vitamin A levels are critical for retinoid signaling and normal pancreatic control of glucose. Vitamin A deficiency is more common during infection, and supplementation reduces severe morbidity and mortality from infectious diseases. Vitamin A modulates activities at the cellular level and, via its interrelationship with hormones such as thyroid, insulin, and corticosteroids, has diffuse metabolic effects on the body. It plays an important role in all stages of wound healing. Vitamin A is known for its ability to stimulate epithelial growth, fibroblasts, granulation tissue, angiogenesis, collagen synthesis, epithelialization, and fibroplasia. Local (topical) and systemic supplementation with vitamin A has been proven to increase dermal collagen deposition. There are numerous animal studies and limited human studies regarding physiologic effect of vitamin A on acute or chronic wounds via systemic or topical administration. The most common use of vitamin A supplementation is to offset steroids' effect. When considering supplementation, the potential benefits must be weighed against the risk of harm. Vitamin A toxicity can be critical and even result in death. The evidence for supplementation with vitamin A is currently limited to expert opinion and is not backed up by rigorous trials. There is an acute need for therapeutic trials with vitamin A supplementations.
Topics: Administration, Oral; Administration, Topical; Animals; Dietary Supplements; Humans; Vitamin A; Vitamin A Deficiency; Vitamins; Wound Healing; Wounds and Injuries
PubMed: 31697447
DOI: 10.1002/ncp.10420 -
Nutrients May 2021Vitamin A is a group of vital micronutrients widely present in the human diet. Animal-based products are a rich source of the retinyl ester form of the vitamin, while... (Review)
Review
Vitamin A is a group of vital micronutrients widely present in the human diet. Animal-based products are a rich source of the retinyl ester form of the vitamin, while vegetables and fruits contain carotenoids, most of which are provitamin A. Vitamin A plays a key role in the correct functioning of multiple physiological functions. The human organism can metabolize natural forms of vitamin A and provitamin A into biologically active forms (retinol, retinal, retinoic acid), which interact with multiple molecular targets, including nuclear receptors, opsin in the retina and, according to the latest research, also some enzymes. In this review, we aim to provide a complex view on the present knowledge about vitamin A ranging from its sources through its physiological functions to consequences of its deficiency and metabolic fate up to possible pharmacological administration and potential toxicity. Current analytical methods used for its detection in real samples are included as well.
Topics: Humans; Nutritional Physiological Phenomena; Vitamin A; Vitamin A Deficiency
PubMed: 34069881
DOI: 10.3390/nu13051703 -
Nutrition Research (New York, N.Y.) Nov 2021The gut microbiome plays important roles in the maintenance of host health and the pathogenesis of many diseases. Diet is a key modulator of the gut microbiome. There is... (Review)
Review
The gut microbiome plays important roles in the maintenance of host health and the pathogenesis of many diseases. Diet is a key modulator of the gut microbiome. There is increasing evidence that nutrients other than fermentable fiber affect the gut microbial composition. In this review, we discuss the effects of vitamins on the gut microbiome, and related gastrointestinal health, based on in vitro, animal and human studies. Some vitamins, when provided in large doses or when delivered to the large intestine, have been shown to beneficially modulate the gut microbiome by increasing the abundance of presumed commensals (vitamins A, B, D, E, and beta-carotene), increasing or maintaining microbial diversity (vitamins A, B, B, C, K) and richness (vitamin D), increasing short chain fatty acid production (vitamin C), or increasing the abundance of short chain fatty acid producers (vitamins B, E). Others, such as vitamins A and D, modulate the gut immune response or barrier function, thus, indirectly influencing gastrointestinal health or the microbiome. Future research is needed to explore these potential effects and to elucidate the underlying mechanisms and host health benefits.
Topics: Animals; Fatty Acids, Volatile; Gastrointestinal Microbiome; Humans; Microbiota; Vitamin A; Vitamins
PubMed: 34798467
DOI: 10.1016/j.nutres.2021.09.001 -
Biomolecules Nov 2023The skin is the most-extensive and -abundant tissue in the human body. Like many organs, as we age, human skin experiences gradual atrophy in both the epidermis and... (Review)
Review
The skin is the most-extensive and -abundant tissue in the human body. Like many organs, as we age, human skin experiences gradual atrophy in both the epidermis and dermis. This can be primarily attributed to the diminishing population of epidermal stem cells and the reduction in collagen, which is the primary structural protein in the human body. The alterations occurring in the epidermis and dermis due to the aging process result in disruptions to the structure and functionality of the skin. This creates a microenvironment conducive to age-related skin conditions such as a compromised skin barrier, slowed wound healing, and the onset of skin cancer. This review emphasizes the recent molecular discoveries related to skin aging and evaluates preventive approaches, such as the use of topical retinoids. Topical retinoids have demonstrated promise in enhancing skin texture, diminishing fine lines, and augmenting the thickness of both the epidermal and dermal layers.
Topics: Humans; Vitamin A; Skin Aging; Skin; Retinoids; Aging
PubMed: 38002296
DOI: 10.3390/biom13111614 -
International Journal of Molecular... Jan 2022Vitamin A is an essential fat-soluble vitamin that occurs in various chemical forms. It is essential for several physiological processes. Either hyper- or... (Review)
Review
Vitamin A is an essential fat-soluble vitamin that occurs in various chemical forms. It is essential for several physiological processes. Either hyper- or hypovitaminosis can be harmful. One of the most important vitamin A functions is its involvement in visual phototransduction, where it serves as the crucial part of photopigment, the first molecule in the process of transforming photons of light into electrical signals. In this process, large quantities of vitamin A in the form of 11--retinal are being isomerized to all--retinal and then quickly recycled back to 11--retinal. Complex machinery of transporters and enzymes is involved in this process (i.e., the visual cycle). Any fault in the machinery may not only reduce the efficiency of visual detection but also cause the accumulation of toxic chemicals in the retina. This review provides a comprehensive overview of diseases that are directly or indirectly connected with vitamin A pathways in the retina. It includes the pathophysiological background and clinical presentation of each disease and summarizes the already existing therapeutic and prospective interventions.
Topics: Gene Expression Regulation; Humans; Light Signal Transduction; Retinal Diseases; Signal Transduction; Vitamin A
PubMed: 35162940
DOI: 10.3390/ijms23031014 -
Nutrition in Clinical Practice :... Oct 2019Vitamin A is an essential micronutrient that comes in multiple forms, including retinols, retinals, and retinoic acids. Dietary vitamin A is absorbed as retinol from... (Review)
Review
Vitamin A is an essential micronutrient that comes in multiple forms, including retinols, retinals, and retinoic acids. Dietary vitamin A is absorbed as retinol from preformed retinoids or as pro-vitamin A carotenoids that are converted into retinol in the enterocyte. These are then delivered to the liver for storage via chylomicrons and later released into the circulation and to its biologically active tissues bound to retinol-binding protein. Vitamin A is a crucial component of many important and diverse biological functions, including reproduction, embryological development, cellular differentiation, growth, immunity, and vision. Vitamin A functions mostly through nuclear retinoic acid receptors, retinoid X receptors, and peroxisome proliferator-activated receptors. Retinoids regulate the growth and differentiation of many cell types within skin, and its deficiency leads to abnormal epithelial keratinization. In wounded tissue, vitamin A stimulates epidermal turnover, increases the rate of re-epithelialization, and restores epithelial structure. Retinoids have the unique ability to reverse the inhibitory effects of anti-inflammatory steroids on wound healing. In addition to its role in the inflammatory phase of wound healing, retinoic acid has been demonstrated to enhance production of extracellular matrix components such as collagen type I and fibronectin, increase proliferation of keratinocytes and fibroblasts, and decrease levels of degrading matrix metalloproteinases.
Topics: Humans; Receptors, Retinoic Acid; Retinoids; Retinol-Binding Proteins; Vitamin A; Wound Healing
PubMed: 31389093
DOI: 10.1002/ncp.10376 -
Journal of Drugs in Dermatology : JDD Jun 2022Recent changes to the iPLEDGE platform left providers without the ability to prescribe isotretinoin to their patients. A potential substitute for isotretinoin could be... (Review)
Review
BACKGROUND
Recent changes to the iPLEDGE platform left providers without the ability to prescribe isotretinoin to their patients. A potential substitute for isotretinoin could be beneficial when the drug is unavailable. Prior to the FDA approval of isotretinoin, a vitamin A derivative, vitamin A was studied for its use in acne management.
OBJECTIVE
To review the potential of vitamin A to serve as a substitute for isotretinoin when the latter drug is inaccessible.
METHODS
We conducted a review of published literature from 1931 to 2021, regarding the use of vitamin A in acne treatment, using PubMed and Google Scholar databases. Nine studies were selected after reviewing articles for relevancy to our topic.
RESULTS
Eight out of the 9 studies noted improvement in patients’ acne with vitamin A use. Ranges of doses used were 36,000 I/U daily to 500,000 I/U daily, with 100,000 I/U daily being the most common. Side effects were mainly mucocutaneous in nature.
LIMITATIONS
Many of the trials included in our review were published over 50 years prior and lack standardized components of clinical trials today.
CONCLUSION
Oral vitamin A could potentially serve as a substitute for isotretinoin in acne management for select patients. However, due to its teratogenicity, potential for toxicity, and long half-life, strict monitoring under the care of a medical provider is prudent. Since vitamin A is available without a prescription, strict monitoring cannot be assured, and especially careful patient selection and education would be essential. J Drugs Dermatol. 2022;21(6):683-686. doi:10.36849/JDD.6781.
Topics: Acne Vulgaris; Administration, Oral; Dermatologic Agents; Humans; Isotretinoin; Vitamin A
PubMed: 35674761
DOI: 10.36849/JDD.6781 -
Alternative Therapies in Health and... Jul 2021Vitamins and their derivatives are used extensively in the field of dermatology to treat a range of conditions, both benign and malignant. Additionally, over the past... (Review)
Review
BACKGROUND
Vitamins and their derivatives are used extensively in the field of dermatology to treat a range of conditions, both benign and malignant. Additionally, over the past decade, vitamin supplements have been heavily advertised for improving overall health. Due to the widespread use of vitamins and their derivatives for dermatologic conditions, a comprehensive review of the evidence is needed.
OBJECTIVE
Here we review several of the well-established uses of vitamins A, B, C, and D in the management of dermatologic conditions ranging from acne vulgaris to malignant melanoma. Additionally, we examine the dermatologic consequences of both deficiency and excess of vitamins A, B, C, and D. Finally, we delve into newer applications for these vitamins and evaluate the evidence behind them.
CONCLUSION
Vitamins, in both topical and oral forms, play a key role in treating many dermatologic conditions. Some of the newer applications of vitamins, such as the use of vitamin B3 for non-melanoma skin cancer prevention, vitamin B6 for prevention of chemotherapy-induced alopecia, and vitamin C as an adjuvant treatment for malignant melanoma, appear promising. Further data is needed to validate these findings. Additionally, many people use vitamin B7 for hair, skin, and nail health. There is evidence that supports vitamin B7 supplementation in patients with uncombable hair syndrome, brittle nail syndrome, and seborrheic dermatitis. Some studies Some studies have also demonstrated a benefit in healthy individuals, although other studies have shown a neutral effect. Further randomized controlled trials are needed. Likewise, the use of vitamin D for the treatment of atopic dermatitis has conflicting results and requires further investigation. New research continues to emerge regarding vitamin supplementation, and it is an important topic for dermatologists.
Topics: Ascorbic Acid; Dermatologists; Dietary Supplements; Humans; Vitamin A; Vitamin D; Vitamins
PubMed: 33245705
DOI: No ID Found -
Current Opinion in Pediatrics Apr 2022Although vitamin A deficiency (VAD) is rare in well resourced countries, there is a growing trend of VAD in at-risk pediatric populations. Early diagnosis is critically... (Review)
Review
PURPOSE OF REVIEW
Although vitamin A deficiency (VAD) is rare in well resourced countries, there is a growing trend of VAD in at-risk pediatric populations. Early diagnosis is critically important to prevent its associated morbidity and mortality. This review highlights key lessons for evaluation, diagnosis, and management of children with xerophthalmia in the United States. It synthesizes the latest findings from the literature on the pathophysiology, epidemiology, risk factors, evaluation, and management of VAD in low-prevalence areas.
RECENT FINDINGS
Vitamin A is crucial for maintaining the functional integrity of the eye, immune system, skin, and mucous membranes. Despite the scarcity of VAD in developed countries, there are increasing reports of VAD in at-risk children, including those with autism spectrum disorder and gastrointestinal conditions. There is a broad range of manifestations of VAD, posing a diagnostic challenge. Familiarity with the variable presentations of VAD and having a high index of suspicion in at-risk populations can aid in its early diagnosis. Systemic vitamin A supplementation and a multidisciplinary approach are important components of the management of VAD.
SUMMARY
Even in well resourced countries, VAD should remain on the differential in patients with risk factors who present with relevant signs and symptoms. Early diagnosis and appropriate involvement of a multidisciplinary care team can help prevent morbidity and mortality associated with VAD.
Topics: Autism Spectrum Disorder; Child; Humans; Prevalence; Vitamin A; Vitamin A Deficiency; Xerophthalmia
PubMed: 35125379
DOI: 10.1097/MOP.0000000000001110