what is vitamin a for
Vitamin A
Vitamin A is needed by the retina of the eye in the form of retinal , which combines with protein opsin to form rhodopsin the light-absorbing molecule , that is necessary for both low-light ( scotopic vision) and color vision .
Vitamin A Retinol Human nutrition Vitamin E Vitamin C Vitamin D Vitamin B12 Health effects of electronic cigarettes Nutritional neuroscience Acne Β-Carotene Niacin Copper in biology Vitamin B6 Cat food Murine respirovirus Health effects of Bisphenol A N-Acylethanolamine Riboflavin Breastfeeding Zinc Induced stem cells Lead poisoning Hepatitis Vitamin K Epstein–Barr virus–associated lymphoproliferative diseases Immune system Iron Malaria Dietary supplement Long-term effects of alcohol Chemotherapy Crohn's disease Genetically modified food controversies Ovarian cancer Tocopherol Ulcerative colitis Cholestasis Alcohol (drug) Innate lymphoid cell Omega-3 fatty acid Chromium Cystic fibrosis Caffeine Aspirin Malnutrition Vitamin Vitamin B12 deficiency Chernobyl disaster Ozone Tuberculosis management Anabolic steroid Magnesium in biology Chloroplast Genetically modified organism Breast cancer Infant mortality Rheumatoid arthritis Health effects of tobacco Birth defect Metabolic dysfunction–associated steatotic liver disease Pharmacokinetics of estradiol Spironolactone Biotin Dopamine Lupus Radiation effects from the Fukushima Daiichi nuclear disaster Isotretinoin Gut microbiota Fat Horse colic Vitamin A deficiency Electronic cigarette and e-cigarette liquid marketing Epigenetics Influenza HIV/AIDS Cholesterol Addiction Amphetamine Nicotine Preterm birth Lyme disease Combined oral contraceptive pill Marginal zone B-cell lymphoma Arsenic poisoning Genetically modified food Cocaine RNA interference Multiple sclerosis Adaptation (eye) Morphine Copper Drosophila melanogaster Thiamine Iron-deficiency anemia Carotene Glucose Coeliac disease Vaccine hesitancy Fetal alcohol spectrum disorder Epilepsy Dioxins and dioxin-like compounds Chronic obstructive pulmonary disease Sepsis Development communication Skeletal muscle Choline Dementia Type 1 diabetes Alcohol and cancer Helicobacter pylori Feminizing hormone therapy Functional hypothalamic amenorrhea Drugs in pregnancy Gene therapy Selenium in biology Evidence of common descent Mitochondrion Colorectal cancer Serotonin Endocrine disruptor Amyotrophic lateral sclerosis Pantothenic acid Soybean Obesity Carcinogenesis Opioid Glyphosate In vitro fertilisation TRPV6 Hemoglobin Congenital adrenal hyperplasia due to 21-hydroxylase deficiency Manganese Benzodiazepine Vitamin B3 Phosphorus Hypervitaminosis A Ebola Free fatty acid receptor 2 Melioidosis Food allergy CYP4F2 Air pollution Insulin List of Supernatural characters Antioxidant Pharmacokinetics of progesterone Human brain Kidney stone disease Health in Nepal Arsenic Plasma cell dyscrasias List of Supernatural and The Winchesters characters Bicalutamide Canadian health claims for food Macrophage Responses to the COVID-19 pandemic in April 2020 Liver Antibiotic Radiation therapy Stroke Management of HIV/AIDS Synthetic biology CRISPR gene editing Ketogenic diet Antimicrobial resistance Testosterone Electronic cigarette Neanderthal Selenium Sarcoidosis Dog health Attention deficit hyperactivity disorder Metal–organic framework Toxoplasmosis Physiological effects in space Iodine in biology Pharmacology of bicalutamide MicroRNA Antidepressant HPV-positive oropharyngeal cancer N,N-Dimethyltryptamine Asthma Glycolysis Joseph Lister Melanoma Nerve guidance conduit Molybdenum Regulatory T cell Jagannath Ganguly Adaptive immune system Atherosclerosis Vitamin D deficiency Trans fat Biology History of Australia Well-being contributing factors Allergy Pneumonia Causes of autism Metabolism Diabetes management Alkali metal Smallpox Virus Metformin Cardiovascular disease Maternal health Irritable bowel syndrome Dietary fiber Heart failure Autism spectrum Millennials Human papillomavirus infection Alcoholism Golden rice Staphylococcus aureus Psilocybin Preventive healthcare Alzheimer's disease Infant formula Epigenetics of physical exercise Fibromyalgia Selective serotonin reuptake inhibitor Estrogen (medication) Child development LSD Cannabis (drug) Vegetarianism Smith–Lemli–Opitz syndrome Insulin (medication) Particulates Race and health in the United States Cortisol Photodynamic therapy Retinal Cat cognitive support diets Methamphetamine Sickle cell disease Warfarin Tuberculosis Childbirth Animal testing Cultured meat Lead Lung cancer Major depressive disorder Pre-eclampsia Leptin Tooth decay Liver support system Glossary of baseball terms Free fatty acid receptor 4 Vegetarian and vegan dog diet Traditional Chinese medicine Institutional racism Fine chemical Leptospirosis COVID-19 misinformation Autism therapies Vegan nutrition Nonsteroidal anti-inflammatory drug Type 2 diabetes Lemur Paracetamol Homeostasis Lysergic acid diethylamide Healthcare in the United States Economic history of the United States Schizophrenia Veganism Perlecan Progestogen (medication) Methylprednisolone Treatment of equine lameness List of dangerous snakes Soil Side effects of cyproterone acetate Transforming growth factor beta Biofilm DNA Hashimoto's thyroiditis Sjögren syndrome Modafinil European Union law Zinc in biology Signal transduction Boron ATP-binding cassette transporter Red imported fire ant Organ-on-a-chip Cattle South African labour law Economic history of the United Kingdom Macular degeneration Hypoxia (medicine) Index of oncology articles Blockade of Germany (1939–1945) Cancer epigenetics Milk allergy Neglected tropical diseases Pregnancy Genetically modified crops Atrial fibrillation Inflammation Glycogen storage disease type I Oxygen toxicity Light in painting Hookworm infection Western African Ebola virus epidemic Phagocyte Human digestive system Risk factors for breast cancer Water fluoridation Multiple myeloma Depressant Maternal effect Ultraviolet Infection Mammal HIV DNA vaccine Cataract surgery Physiology of underwater diving Retina Osteogenesis imperfecta Cancer immunotherapy COVID-19 pandemic Photosynthesis Arachidonate 5-lipoxygenase Nutrition and pregnancy Antibody Lung Zebrafish Measles Anorexia nervosa Hydroxycarboxylic acid receptor 2 T cell Bacteria Myocardial infarction Postpartum psychosis Adolescence Hypertension MDMA Epigenetics of autoimmune disorders Rabeprazole Carotenoid Agriculture Ethanol Proteasome Fungus Silver nanoparticle Maize Plasmodium falciparum Marine life Plastic pollution Linezolid Graphene Progesterone (medication) Enzyme Meat Glaucoma Huntington's disease ALS Cigarette Protein Political positions of Hillary Clinton HPV vaccine Generation Z in the United States Heart Fracking in the United States Risk factors of schizophrenia Β-Hydroxy β-methylbutyric acid Dementia with Lewy bodies Bipolar disorder Schistosomiasis Health care systems by country Fentanyl Diseases of poverty Free fatty acid receptor 1 Pharmaceutical industry Tissue engineering Domestic violence Harmful algal bloom Migraine Organic farming Nutrient Traumatic brain injury Hypothyroidism History of medicine Nicotinamide adenine dinucleotide Arguments for and against drug prohibition Obstructive sleep apnea Meningitis Gasoline Actin Dengue fever HIV/AIDS in Russia Mesothelioma Lactobacillus vaccine Ammonia Vagina Flint water crisis Cerebral palsy Depleted uranium International Space Station Statin Ozone depletion Carnitine Lipid signaling Frog Preimplantation genetic diagnosis Human microbiome Osteoporosis Common ostrich Toxoplasma gondii Management of multiple sclerosis Effects of the Chernobyl disaster United Kingdom labour law Retinitis pigmentosa Cell signaling Women in science Trace metal stable isotope biogeochemistry Natural killer cell DNA methylation Visual cycle Lipid Plant defense against herbivory Mental disorder Water Reactive oxygen species History of penicillin Colony collapse disorder Epigenetics of anxiety and stress–related disorders Testosterone (medication) Retinoic acid Carbon monoxide poisoning Anticancer gene Bladder cancer Influenza vaccine Human iron metabolism Interleukin-1 family Subprime mortgage crisis Post-traumatic stress disorder Marine plastic pollution Diarrhea Sexual and reproductive health Progesterone Paracetamol poisoning Urinalysis Cannabis in Italy Circadian rhythm Chlorpyrifos Sulfatide Pharmacology of cyproterone acetate Vaccine Anemia Central nervous system effects from radiation exposure during spaceflight Alcohol dehydrogenase Fluoxetine Silicon Psychosis Ataxia–telangiectasia COVID-19 vaccination in Bulgaria Follicular lymphoma Cholera Natural scientific research in Canada Presidency of Donald Trump Cirrhosis Health in Bangladesh Industrial Revolution Causes of cancer Organic food DNA damage (naturally occurring) Clozapine Polio Pesticide Thyroid Dry eye syndrome Potato Complete blood count South African criminal law Hormone replacement therapy Probiotic Methicillin-resistant Staphylococcus aureus Pernicious anemia Beluga whale DDT Perfluorooctanoic acid Cooper's hawk Senior dog diet Neurotoxin Side effects of bicalutamide Amphibian History of life 5-Hydroxyeicosatetraenoic acid Lithium (medication) Breast milk Attachment theory Sleep deprivation Mammalian kidney Life extension Recent human evolution Pancreatic cancer Protein (nutrient) Luftnachrichten Abteilung 350 Organ transplantation Generation Z Apoptosis Tumor microenvironment Mumps O-GlcNAc Wound healing Chronic fatigue syndrome Free fatty acid receptor 3 Neuroscience of sleep Dental amalgam controversy Cancer treatment Ecology T helper cell Immune tolerance Environmental impact of pharmaceuticals and personal care products Microplastics Human genetic resistance to malaria Ketotifen White-tailed eagle Penicillin History of Eglin Air Force Base Domestication of the dog Lithium-ion battery Estradiol (medication) Biodiesel Cyanobacteria Human skin color Breast augmentation Health effects of radon Diethylstilbestrol Reading Fish oil Mold health issues Lipopolysaccharide Heroin Puberty Biology of depression Estramustine phosphate Biological functions of nitric oxide Opsin NF-κB Hydroxyprogesterone caproate Epoxyeicosatrienoic acid Fatty acid metabolism Autoimmune disease Milk fat globule membrane Tretinoin Dog food Urine test strip Binge drinking Decompression theory Memory Selective estrogen receptor modulator Zinc deficiency Postpartum depression Permian–Triassic extinction event Inflammatory bowel disease Bariatric surgery Stem-cell therapy Southern bluefin tuna Obsessive–compulsive disorder Honey Domestic rabbit Reelin Methylphenidate Epigenetics of neurodegenerative diseases Abortion Healthcare in Canada Hepatitis C Potassium Noise-induced hearing loss Native Americans in the United States CRISPR Lymphocytic choriomeningitis Tartan Homelessness Effects of climate change on agriculture History of science and technology in Africa Physical attractiveness Plutonium Child abuse Cluster of Excellence Frankfurt Macromolecular Complexes Gout Synephrine Thomas P. Stossel Ethylene oxide History of Germany List of Doctor Who universe creatures and aliens Spinocerebellar ataxia type 1 Adipose tissue Botany Eating disorder Hepatitis B Cephalopod Leukotriene B4 receptor 2 Jaundice Famine Insect morphology Gestational diabetes Microbial symbiosis and immunity History of chemistry Spanish flu Plant nutrition Brain Endometrial cancer Atomic bombings of Hiroshima and Nagasaki Enzyme inhibitor German government response to the COVID-19 pandemic Norethisterone Origin of the domestic dog Per- and polyfluoroalkyl substances Estradiol Ciprofloxacin Human Logology (science) Pollution in California Nitrous oxide 2009 swine flu pandemic Action potential Ixodes holocyclus Ketamine Miscegenation Gamma delta T cell Rare-earth element Technological and industrial history of 20th-century Canada Evolutionary history of plants Science and technology in Venezuela Cannabidiol Urban forestry Dark skin Physiology of decompression Biosensor Polycystic ovary syndrome Silviculture Childhood obesity Women in Islam Botulism Sunscreen Borderline personality disorder Vitamin deficiency Natural product Rotavirus Retinoid American cuisine Gastric bypass surgery Antimalarial medication Innate immune system Red blood cell Naltrexone Agriculture in California Responses to the COVID-19 pandemic in July 2020 Management of depression Supercapacitor European debt crisis Face masks during the COVID-19 pandemic Eicosanoid Group B streptococcal infection History of the nude in art Cancer stem cell Hummingbird Benzene Deep vein thrombosis Interferon gamma Perovskite solar cell Carbon dioxide Sulfur GATA2 deficiency Eggs as food G protein-coupled receptor Incarceration of women in the United States Phthalates Fluorine Evolution Environmental toxicology Tobacco smoking Antipsychotic Crocodilia Affordable Care Act Enobosarm Escherichia coli Cathode-ray tube History of women in the United States Iron in biology Prostate cancer Catenin beta-1 Kinetic isotope effect Opioid use disorder Psychology White wine Climate change in Washington Agriculture in the United Kingdom Diving rebreather Lysine Nivalenol Food fortification The Dresden Files characters Taste Succinic acid Homologous recombination Hyperthyroidism Temporomandibular joint dysfunction Spinal cord injury Brain tumor Coenzyme Q10 Oxygen Elagolix Nucleoid Family planning Endometriosis Diffuse large B-cell lymphoma Hunger in the United States 20-Hydroxyeicosatetraenoic acid Deforestation Osteopontin Rebreather diving Oxycodone Tesla Autopilot Rice Wildfire Aluminium Oxidative phosphorylation Acute lymphoblastic leukemia Biofeedback Glucocorticoid Equine nutrition Citrinin Electronic waste Fish anatomy List of My Hero Academia characters Sustainable fashion Social media Literacy Kawasaki disease COVID-19 vaccine Bird CREB-binding protein Aggression Glucokinase Nuclear power debate Pharmacodynamics of estradiol Alcohol and health Transgenerational epigenetic inheritance Scurvy WASH Lactose intolerance Fish physiology Poverty Saccharomyces cerevisiae Citric acid cycle Sense 44th Medical Brigade Sixth Labour Government of New Zealand Insulin resistance Chagas disease Stem cell Gluten-related disorders Docetaxel Birth control Genome editing Histone acetylation and deacetylation Anthrax Lipoxin History of autism Jellyfish Gene Marine microorganisms Radon Psychopathy Human genetic enhancement Fukushima nuclear accident Sheep Survivin Mercury poisoning Hypoxia in fish Slavery in ancient Rome 2008 Chinese milk scandal Role of Christianity in civilization Women's Health Initiative Maternal death Hematopoietic stem cell transplantation Evolutionary psychology Incarceration in the United States Aquaculture Nuclear winter Responses to the COVID-19 pandemic in May 2020 Ubiquitin Global health Brain–computer interface Gene therapy of the human retina Chocolate Diazepam Facioscapulohumeral muscular dystrophy Butyric acid Invasive species List of Dutch inventions and innovations Endogenous retrovirus Fructose Orthomolecular medicine Telehealth Uranium mining Tamoxifen Long-eared owl Fake news Wnt signaling pathway United Kingdom constitutional law Estrogen Social history of viruses United States labor law Retinal dehydrogenase Bird vision Crisis in Venezuela Neonatal infection Gene expression Portugal Gender disparities in health Fluoride Pheochromocytoma Developmental psychology Salmonella Doxepin Creosote Snowy owl Lymphatic system Multisystem inflammatory syndrome in children Effects of long-term benzodiazepine use Flutamide NMDA receptor Serotonin–norepinephrine–dopamine reuptake inhibitor Acute myeloid leukemia Leprosy Obesogen Carotenosis Tourette syndrome Pathology of multiple sclerosis Heated tobacco product Bengal famine of 1943 Xenotransplantation Alcohol and Native Americans German radio intelligence operations during World War II New Deal Hepatocellular carcinoma Impulsivity Renal cell carcinoma Human skin Climate change Reproductive justice Biological pump Thraustochytrids Deepwater Horizon oil spill Major histocompatibility complex CSNK1D Heterologous expression Syphilis Value-form Cell nucleus Gluten-free diet Human physiology of underwater diving Economic impact of the COVID-19 pandemic Sirolimus Red-tailed hawk Cell cycle Codeine Serotonin–norepinephrine reuptake inhibitor Food policy Tyrannosaurus Effects of cannabis Antibiotic use in livestock Cervical cancer Human genome Chlorine Transgenerational trauma Retinol dehydrogenase Ethnomusicology Toll-like receptor Health equity Cholecalciferol Melanin Gut-specific homing Chromium(III) picolinate Phenylketonuria Iron deficiency Folate deficiency Iran–Iraq War Artemisinin Ocean acidification Interferon Respiratory syncytial virus Trypanosoma brucei Albendazole Mercury in fish Hearing loss Digestion Human food Optogenetics Attention deficit hyperactivity disorder management Peanut allergy 2007–2008 financial crisis Sertraline Uranium Imperial Roman army Sea Respiratory system Carbohydrate Culture of the United Kingdom Kwashiorkor Human sexuality Thorium Unethical human experimentation in the United States Pseudomonas aeruginosa Down syndrome Neural tube defect Multivitamin Egg allergy Food and Drug Administration History of the Labour Party (UK) Bupropion List of recurring The Simpsons characters Magnesium transporter Photoaging Hereditary hemorrhagic telangiectasia Environmental impacts of animal agriculture Hydrogen peroxide Political positions of Ron Paul Nitrogen Nervous system Reindeer Miscarriage Ethanol fuel in Brazil Pancreas Extreme ultraviolet lithography Moclobemide Biochemistry Tyrosine kinase Folding@home List of Garo characters Botulinum toxin Protein adulteration in China Specialized pro-resolving mediators Potential applications of graphene Sonodynamic therapy Eosinophilia Palm oil Latin America Adult neurogenesis Communication of the Trump administration during the COVID-19 pandemic Underwater diving Dinosaur List of characters in the Breaking Bad franchise Coral reef Marine food web Functional magnetic resonance imaging Doxycycline Economy of China Coronary artery disease Visual impairment Gamma-Hydroxybutyric acid Pfizer–BioNTech COVID-19 vaccine Nutrition and cognition Adrenal gland Opium Hugo W. Koehler Drospirenone Smoking Vietnam War Microbial toxin Antiandrogen Abiogenesis Scuba diving Yeast History of Austria Fish Human body Cytochrome P450 Acupuncture Bile acid Nickel Dingo Arsenic biochemistry Fatty acid synthesis Head and neck cancer Management of Parkinson's disease COVID-19 testing Autophagy Mercury regulation in the United States Genetically modified animal Decompression sickness Economy of India Environmental policy of the Donald Trump administration History of Western civilization Colchicine Nuclear power Water supply and sanitation in the United States Maritime history of California