A family of carcinogenic toxins produced by certain fungi endemic to areas with hot and humid climates. Aflatoxins are commonly found in agricultural crops such as maize (corn), peanuts, cottonseed, and tree nuts. In people who are infected with hepatitis B, aflatoxin markedly increases the risk for liver cancer.^[1]

The death rate from all causes of death for a population in a given time period.

A molecule that inhibits oxidative damage to DNA, proteins, and lipids in cells. Oxidative damage plays a role in the aging process, cancer, and neurodegeneration. Many vitamins and plant-based compounds are antioxidants.

A type of omega-6 polyunsaturated fat. Arachidonic acid is found in the phospholipid components of cell membranes, especially those in the brain, muscles, and liver. It plays key roles in the body’s inflammatory process. In particular, it promotes the formation of eicosanoids, a class of proinflammatory compounds, following injury or irritation.

A test used in laboratory medicine, pharmacology, environmental biology, and molecular biology to determine the content or quality of specific components.

The shrinking or wasting away of cells, organs, or tissues that may occur as part of a disease process, trauma, or aging.

Proteins that provide favorable conditions for the correct folding of other proteins. Newly made proteins usually must fold from a linear chain of amino acids into a three-dimensional form. Group II chaperonins, the variety found in eukaryotic cytosol, are also referred to as CCT, which stands for "chaperonin containing TCP-1."

The extent and rate at which drugs or other substances, such as plant-based dietary compounds, enter the body’s circulation. Bioavailability is influenced by a variety of factors, including dose, the presence of other foods or substances, and interindividual differences in metabolism due to gut absorptive surface and commensal microbial populations.

A measurable substance in an organism that is indicative of some phenomenon such as disease, infection, or environmental exposure.

A chemical used during the production of polycarbonate plastics and epoxy resins. BPA is an endocrine disruptor. It can mimic naturally occurring hormones in the body like estrogens, androgens, and thyroid hormones, potentially altering normal hormonal signals. BPA exposure is widespread due to extensive use of plastics and other BPA-containing products.

A highly selective semi-permeable barrier in the brain made up of endothelial cells connected by tight junctions. The blood-brain barrier separates the circulating blood from the brain's extracellular fluid in the central nervous system. Whereas water, lipid-soluble molecules, and some gases can pass through the blood-brain barrier via passive diffusion, molecules such as glucose and amino acids that are crucial to neural function enter via selective transport. The barrier prevents the entry of lipophilic substances that may be neurotoxic via an active transport mechanism.

The practice of long-term restriction of dietary intake, typically characterized by a 20 to 50 percent reduction in energy intake below habitual levels. Caloric restriction has been shown to extend lifespan and delay the onset of age-related chronic diseases in a variety of species, including rats, mice, fish, flies, worms, and yeast.

A person who is 100 or more years old.

A waxy lipid produced primarily in the liver and intestines. Cholesterol can be synthesized endogenously and is present in all the body's cells, where it participates in many physiological functions, including fat metabolism, hormone production, vitamin D synthesis, and cell membrane integrity. Dietary sources of cholesterol include egg yolks, meat, and cheese.

A tightly coiled molecule of DNA found in the nucleus of a cell. Chromosomes contain the genes and other genetic material for an organism. Humans have 46 chromosomes arranged in 23 pairs. Each chromosome is comprised of long stretches of DNA wrapped around proteins called histones, which provide structural support. At the end of each chromosome is a repetitive nucleotide sequence called a telomere. Telomeres form a protective “cap” – a sort of disposable buffer that gradually shortens with age – that prevents chromosomes from losing genes or sticking to other chromosomes during cell division.

A substance whose presence is essential for the activity of an enzyme. Many minerals and vitamins are cofactors for enzymes.

A secondary bile acid that is produced in order to aid in the digestion of fats and oils. It causes DNA damage and can cause tumorigenesis, particularly in the colon.

A mood disorder characterized by profound sadness, fatigue, altered sleep and appetite, as well as feelings of guilt or low self-worth. Depression is often accompanied by perturbations in metabolic, hormonal, and immune function. A critical element in the pathophysiology of depression is inflammation. As a result, elevated biomarkers of inflammation, including the proinflammatory cytokines interleukin-6 and tumor necrosis factor-alpha, are commonly observed in depressed people. Although selective serotonin reuptake inhibitors and cognitive behavioral therapy typically form the first line of treatment for people who have depression, several non-pharmacological adjunct therapies have demonstrated effectiveness in modulating depressive symptoms, including exercise, dietary modification (especially interventions that capitalize on circadian rhythms), meditation, sauna use, and light therapy, among others.

The biological process in which a cell matures and specializes. Differentiation is essential for the development, growth, reproduction, and lifespan of multicellular organisms. Differentiated cells can only express genes that characterize a certain type of cell, such as a liver cell, for example.

A major contributing factor to aging, cellular senescence, and the development of cancer. Byproducts of both mitochondrial energy production and immune activity are major sources of DNA damage. Additionally, environmental stressors can increase this base level of damage. DNA damage can be mitigated by cellular repair processes; however, the effectiveness of these processes may be influenced by the availability of dietary minerals, such as magnesium, and other dietary components, which are needed for proper function of repair enzymes.

An omega-3 fatty acid found in the human brain and the meat of fatty fish. DHA plays a key role in the development of eye and nerve tissues, and is essential for normal brain function in humans. DHA may also reduce the risk of Alzheimer’s disease1 and cardiovascular disease, and may be useful in treating certain inflammatory conditions, such as rheumatoid arthritis. Dietary sources of DHA include krill oil and the meat and roe of salmon, flying fish, and pollock. [1] Patrick, Rhonda P. "Role of phosphatidylcholine-DHA in preventing APOE4-associated Alzheimer’s disease." The FASEB Journal (2018): fj-201801412R.

A neurotransmitter best known for its role in motor, motivation, and pleasure control. Dopamine also functions as a paracrine (cell-to-cell) hormone in other parts of the body. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Some evidence suggests that dopamine may also be involved in pain modulation.

Any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalyst in specific biochemical reactions.

Genetic control elicited by factors other than modification of the genetic code found in the sequence of DNA. Epigenetic changes determine which genes are being expressed, which in turn may influence disease risk. Some epigenetic changes are heritable.

A vitamin that is readily dissolved in fats or oils. Fat-soluble vitamins are absorbed along with fats in the diet and can be stored in the body’s fatty tissue. Vitamins A, D, E, and K are fat-soluble. Dietary sources of fat-soluble vitamins include fatty fish (such as salmon), nuts, oils, and avocados, among others.

A molecule composed of carboxylic acid with a long hydrocarbon chain that is either saturated or unsaturated. Fatty acids are important components of cell membranes and are key sources of fuel because they yield large quantities of ATP when metabolized. Most cells can use either glucose or fatty acids for this purpose.

A type of water-soluble B-vitamin, also called vitamin B9. Folate is critical in the metabolism of nucleic acid precursors and several amino acids, as well as in methylation reactions. Severe deficiency in folate can cause megaloblastic anemia, which causes fatigue, weakness, and shortness of breath. Certain genetic variations in folate metabolism, particularly those found in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene influences folate status. Inadequate folate status during early pregnancy increases the risk of certain birth defects called neural tube defects, or NTDs, such as spina bifida, anencephaly, and other similar conditions. Folate deficiency and elevated concentrations of homocysteine in the blood are associated with increased risk of cardiovascular disease. Low folate status and/or high homocysteine concentrations are associated with cognitive dysfunction in aging (from mild impairments to dementia). The synthetic form of folate is called folic acid. Sources of folate include most fruits and vegetables, especially green leafy vegetables.

The process in which information stored in DNA is converted into instructions for making proteins or other molecules. Gene expression is highly regulated. It allows a cell to respond to factors in its environment and involves two processes: transcription and translation. Gene expression can be turned on or off, or it can simply be increased or decreased.

One of the most abundant non-essential amino acids in the human body. Glutamine plays key roles in several metabolic functions, including protein and glutathione synthesis, energy production, antioxidant status, and immune function. In addition, it regulates the expression of several genes. Although the body can typically produce all the glutamine it needs, during periods of metabolic stress it must rely on dietary sources of glutamine such as meats, fish, legumes, fruits, and vegetables.

An antioxidant compound produced by the body’s cells. Glutathione helps prevent damage from oxidative stress caused by the production of reactive oxygen species.

An antioxidant produced within cells that converts oxidized glutathione to reduced glutathione. Glutathione reductase is essential for protection against oxidative damage. Oxidative damage is a key factor in many diseases.

A complex mixture of hundreds of related but distinct proteins, mainly gliadin and glutenin, found in wheat. Similar proteins are found in rye (secalin), barley (hordein), and oats (avenin), are evolutionarily connected, and are collectively referred to as “gluten.” Gluten proteins, which are highly resistant to hydrolysis in the human gut, can give rise to pathogenic peptides, which may promote the development of celiac disease or wheat allergy in genetically predisposed people. The global prevalence of celiac disease is 1%, with a statistical range of probability of 0.5–1.26% in the general population in Europe and the US.

A naturally occurring substance capable of stimulating cellular growth, proliferation, healing, and differentiation. Growth factors typically act as signaling molecules between cells. Examples include cytokines and hormones that bind to specific receptors on the surface of their target cells.

An alternative medicine practice based on the concept that the body can cure itself. Homeopathic remedies are made from substances derived from plants, animals, or minerals that have been diluted in water and shaken until there is little, if any, of the original substance left. Homeopaths believe that the original substance leaves a “molecular blueprint” in the water that triggers the body's healing mechanisms.

An organism’s ability to maintain its internal environment within defined limits that allow it to survive. Homeostasis involves self-regulating processes that return critical bodily systems to a particular “set point” within a narrow range of operation, consistent with the organism’s survival.

An amino acid present in the blood. Homocysteine is produced during the metabolism of methionine. Abnormalities in methionine metabolism can lead to elevated homocysteine levels, a condition called hyperhomocysteinemia. Elevated homocysteine levels can contribute to arterial plaque formation and increase the risk of clot formation. Some evidence suggests that elevated homocysteine levels double the risk of developing Alzheimer’s disease. Homocysteine levels vary according to dietary intake, with highest levels associated with consumption of animal protein. Variants in the genes that encode for the enzymes that metabolize homocysteine, specifically MTHFR, or methylenetetrahydrofolate reductase, markedly increase the risk of developing a wide array of diseases, including cardiovascular disease, Alzheimer’s disease, and cancer. High intake of dietary folate (present in leafy greens and other fruits and vegetables) can modulate the harmful effects associated with MTHFR.

Biological responses to low-dose exposures to toxins or other stressors such as exercise, heat, cold, fasting, and xenohormetics. Hormetic responses are generally favorable and elicit a wide array of protective mechanisms. Examples of xenohormetic substances include plant polyphenols – molecules that plants produce in response to stress. Some evidence suggests plant polyphenols may have longevity-conferring effects when consumed in the diet.

A critical element of the body’s immune response. Inflammation occurs when the body is exposed to harmful stimuli, such as pathogens, damaged cells, or irritants. It is a protective response that involves immune cells, cell-signaling proteins, and pro-inflammatory factors. Acute inflammation occurs after minor injuries or infections and is characterized by local redness, swelling, or fever. Chronic inflammation occurs on the cellular level in response to toxins or other stressors and is often “invisible.” It plays a key role in the development of many chronic diseases, including cancer, cardiovascular disease, and diabetes.

A peptide hormone secreted by the beta cells of the pancreatic islets cells. Insulin maintains normal blood glucose levels by facilitating the uptake of glucose into cells; regulating carbohydrate, lipid, and protein metabolism; and promoting cell division and growth. Insulin resistance, a characteristic of type 2 diabetes, is a condition in which normal insulin levels do not produce a biological response, which can lead to high blood glucose levels.

One of the most potent natural activators of the AKT signaling pathway. IGF-1 stimulates cell growth and proliferation, inhibits programmed cell death, mediates the effects of growth hormone, and may contribute to aging and enhancing the growth of cancer after it has been initiated. Similar in molecular structure to insulin, IGF-1 plays a role in growth during childhood and continues later in life to have anabolic, as well as neurotrophic effects. Protein intake increases IGF-1 levels in humans, independent of total caloric consumption.

A physiological condition in which cells fail to respond to the normal functions of the hormone insulin. During insulin resistance, the pancreas produces insulin, but the cells in the body become resistant to its actions and are unable to use it as effectively, leading to high blood sugar. Beta cells in the pancreas subsequently increase their production of insulin, further contributing to a high blood insulin level.

A series of enzymatic reactions that aerobic organisms use to produce energy. Also known as the citric acid cycle or the tricarboxylic acid cycle, the Krebs cycle takes place in the mitochondria. It comprises eight reactions and eight intermediates that break down carbohydrates, fats, and proteins into adenosine triphosphate (ATP) and carbon dioxide. It also produces the precursors of certain amino acids and the reduced form of nicotinamide adenine dinucleotide (NADH), a cofactor for many biological reactions.

A medium chain fatty acid that is composed of 12 hydrocarbons that has very potent antiviral activity, particularly against viruses that contain a viral envelope. It also has antibacterial activity and it plays a role in appetite suppression. Coconut oil is a good source of lauric acid.

Otherwise known as intestinal permeability – a condition in which gaps form between the tight junctions of the endothelial cells that line the gut. These gaps allow pathogens like bacteria or endotoxins – toxins that are released when bacteria die – to leak through the intestinal wall and pass directly into the bloodstream. The most common endotoxin is lipopolysaccharide (LPS), a major component of the cell membrane of gram-negative bacteria. If LPS leaks into the bloodstream, it can trigger an acute inflammatory reaction. LPS has been linked with a number of chronic diseases, including Alzheimer’s disease and cardiovascular disease.

A class of proteins present in many edible plants, such as grains or legumes. Lectins are carbohydrate-binding molecules. They have been referred to as antinutrients for their ability to impair absorption of some nutrients. Many lectins possess hemagglutinin properties, which means they can bind to blood cells and cause them to aggregate. Cooking typically denatures lectins in foods.

A class of saturated fats. Medium-chain triglycerides are composed of medium-length fatty acid chains (six to 12 carbons long) bound by a glycerol backbone. They occur naturally in coconut oil, palm oil, and butter, but they can also be synthesized in a laboratory or food processing setting. Evidence suggests that MCT therapy improves cognitive function in older adults with Alzheimer's disease.^[1] Examples of MCTs include caprylic acid (C8), capric acid (C10), and lauric acid (C12).

The thousands of biochemical processes that run all of the various cellular processes that produce energy. Since energy generation is so fundamental to all other processes, in some cases the word metabolism may refer more broadly to the sum of all chemical reactions in the cell.

A highly addictive psychostimulant drug. Methamphetamine, or “meth,” works by mimicking the actions of dopamine and serotonin, neurotransmitters produced in the brain that influence mood and movement. The drug produces an intense “rush” in users, followed by a hyperalert state. After it wears off, the brain is depleted of its dopamine, and depression is a common result. Methamphetamine appears to have neurotoxic (brain-damaging) effects, destroying brain cells that produce dopamine and serotonin.

A sulfur-containing amino acid that is a constituent of most proteins. It is an essential nutrient in the diet of vertebrates. Methionine restriction in lower organisms has been shown to extend lifespan.

A gene coding for an enzyme that converts homocysteine into methionine; a critical step in the methyl cycle. Natural variation in this gene is common among healthy people, however, some variants have been reported to influence susceptibility to occlusive vascular disease, neural tube defects, Alzheimer’s disease and other forms of dementia, colon cancer, and acute leukemia.

The collection of genomes of the microorganisms in a given niche. The human microbiome plays key roles in development, immunity, and nutrition. Microbiome dysfunction is associated with the pathology of several conditions, including obesity, depression, and autoimmune disorders such as type 1 diabetes, rheumatoid arthritis, muscular dystrophy, multiple sclerosis, and fibromyalgia.

Vitamins and minerals that are required by organisms throughout life in small quantities to orchestrate a range of physiological functions. The term micronutrients encompasses vitamins, minerals, essential amino acids, essential fatty acids.

Tiny organelles inside cells that produce energy in the presence of oxygen. Mitochondria are referred to as the "powerhouses of the cell" because of their role in the production of ATP (adenosine triphosphate). Mitochondria are continuously undergoing a process of self-renewal known as mitophagy in order to repair damage that occurs during their energy-generating activities.

The process by which new mitochondria are made inside cells. Many factors can activate mitochondrial biogenesis including exercise, cold shock, heat shock, fasting, and ketones. Mitochondrial biogenesis is regulated by the transcription factor peroxisome proliferator-activated receptor gamma coactivator 1-alpha, or PGC-1α.

An agent, such as radiation or a chemical substance. that causes genetic mutation.

A protein produced predominantly by skeletal muscle. Myostatin negatively regulates the growth and differentiation of muscle cells. Genetic variants in the gene for myostatin can cause muscle hypertrophy (excessive growth). Mice engineered to lack myostatin exhibit about a doubling of skeletal muscle mass throughout the body. Myostatin inhibitors block the action of myostatin and have been used therapeutically in muscle wasting diseases and also in the bodybuilding community.

A broad range of disorders caused by the progressive death of neurons in the central and peripheral nervous systems. Common neurodegenerative diseases include Alzheimer's disease, Parkinson's disease, Huntington’s disease, and multiple sclerosis. Although treatments are available for some neurodegenerative diseases, there are currently no cures.

The process of forming new neurons. Neurogenesis is essential during embryonic development, but also continues in certain brain regions throughout human lifespan.

One of four nitrogen-containing molecules that comprise DNA. A nucleotide consists of one of four chemicals, called a “base,” plus one molecule of sugar and one molecule of phosphoric acid. Nucleotides are typically identified by the first letter of their base names: adenine (A), cytosine (C), guanine (G), and thymine (T). They form specific pairs (A with T, and G with C), and their bonds provide the helical structure of the DNA strand.

A type of polyunsaturated fat that is essential for human health. Omega-3 fatty acids influence cell membrane integrity and affect the function of membrane-bound cellular receptors. They participate in pathways involved in the biosynthesis of hormones that regulate blood clotting, contraction and relaxation of artery walls, and inflammation. They have been shown to help prevent heart disease and stroke, may help control lupus, eczema, and rheumatoid arthritis, and may play protective roles in cancer and other conditions. Omega-3 fatty acids include alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is found mainly in plant oils such as flaxseed, soybean, and canola oils. DHA and EPA are found in fish and other seafood. The human body can convert some ALA into EPA and then to DHA, but the efficiency of the process varies between individuals.

Highly reactive molecules that have the ability to oxidize other molecules and cause them to lose electrons. Common oxidants are oxygen, hydrogen peroxide, and superoxide anion.

A chemical reaction in which an atom, molecule, or ion loses one or more electrons. Oxidation of biological molecules is associated with oxidative stress, a key driver of many chronic diseases.

A neurodegenerative disorder that affects the central nervous system. Parkinson’s disease is caused by destruction of nerve cells in the part of the brain called the substantia nigra. It typically manifests later in life and is characterized by tremors and a shuffling gait.

A class of chemical compounds produced in plants in response to stressors. Polyphenols contribute to the bitterness, astringency, color, flavor, and fragrance of many fruits and vegetables. They often serve as deterrents to insect or herbivore consumption. When consumed in the human diet, polyphenols exert many health benefits and may offer protection against development of cancers, cardiovascular diseases, diabetes, osteoporosis, and neurodegenerative diseases. Dietary sources of polyphenols include grapes, apples, pears, cherries, and berries, which provide as much as 200 to 300 mg polyphenols per 100 grams fresh weight.

The area of the brain located in the front portion of the frontal lobe, just behind the area commonly known as the forehead. The prefrontal cortex is involved in a variety of higher cognitive functions and behaviors such as executive function and expression of appropriate social behavior.

A group of lipid-signaling molecules that have diverse hormone-like effects. Prostaglandins play roles in inflammation, vasoconstriction or vasodilation, aggregation or disaggregation of platelets, calcium movement, cell growth, and thermoregulation. Prostaglandins are produced in many places throughout the human body.

Oxygen-containing chemically-reactive molecules generated by oxidative phosphorylation and immune activation. ROS can damage cellular components, including lipids, proteins, mitochondria, and DNA. Examples of ROS include: peroxides, superoxide, hydroxyl radical, and singlet oxygen.

A related byproduct, reactive nitrogen species, is also produced naturally by the immune system. Examples of RNS include nitric oxide, peroxynitrite, and nitrogen dioxide.

The two species are often collectively referred to as ROS/RNS. Preventing and efficiently repairing damage from ROS (oxidative stress) and RNS (nitrosative stress) are among the key challenges our cells face in their fight against diseases of aging, including cancer.

A mental disorder characterized by abnormal social behavior and failure to understand what is real. Common symptoms include false beliefs, unclear or confused thinking, hearing voices that others do not, reduced social engagement and emotional expression, and a lack of motivation. People with schizophrenia often have additional mental health problems such as anxiety disorders, major depressive illness, or substance use disorders.

A disease caused by vitamin C deficiency. Scurvy is characterized by bleeding, swollen gums, poor wound healing, joint pain, and bruising. Clinical features of scurvy appear in a person in as little as 84 to 97 days of vitamin C depletion. As scurvy progresses, a person might experience shortness of breath, dry eyes, joint swelling, weakness, fatigue, and depression.

A small molecule that functions as both a neurotransmitter and a hormone. Serotonin is produced in the brain and gut and facilitates the bidirectional communication between the two. It regulates many physiological functions, including sleep, appetite, mood, thermoregulation, and others. Many antidepressants are selective serotonin reuptake inhibitors (SSRIs), which work by preventing the reabsorption of serotonin, thereby increasing extracellular levels of the hormone.

A cell that has the potential to develop into different types of cells in the body. Stem cells are undifferentiated, so they cannot do specific functions in the body. Instead, they have the potential to become specialized cells, such as muscle cells, blood cells, and brain cells. As such, they serve as a repair system for the body. Stem cells can divide and renew themselves over a long time. In 2006, scientists reverted somatic cells into stem cells by introducing Oct4, Sox2, Klf4, and cMyc (OSKM), known as Yamanaka factors.^[1]

An enzyme that extends the telomeres of chromosomes. Telomerase adds specific nucleotide sequences to the ends of existing chromosomes. Telomerase activity is highly regulated during development, and its activity is at an almost undetectable level of activity in fully developed cells. This lack of activity causes the cell to age. If telomerase is activated in a cell, the cell will continue to grow and divide, or become "immortal," which is important to both aging and cancer. Telomerase enzyme activity has been detected in more than 90 percent of human cancers.

Distinctive structures comprised of short, repetitive sequences of DNA located on the ends of chromosomes. Telomeres form a protective “cap” – a sort of disposable buffer that gradually shortens with age – that prevents chromosomes from losing genes or sticking to other chromosomes during cell division. When the telomeres on a cell’s chromosomes get too short, the chromosome reaches a “critical length,” and the cell stops dividing (senescence) or dies (apoptosis). Telomeres are replenished by the enzyme telomerase, a reverse transcriptase.

An animal that has had its genome altered through the use of genetic engineering techniques, usually during early embryonic stages. Transgenic techniques are routinely used to introduce human disease genes or other genes of interest into strains of laboratory animals in order to study the function or pathology involved with a particular gene.

A molecule composed of a glycerol molecule bound to three fatty acids. Triglycerides are the primary component of very-low-density lipoproteins (VLDL). They serve as a source of energy. Triglycerides are metabolized in the intestine, absorbed by intestinal cells, and combined with cholesterol and proteins to form chylomicrons, which are transported in lymph to the bloodstream.

An essential amino acid. Tryptophan plays key roles in the biosynthesis of proteins and is a precursor to several molecules with physiological significance, including melatonin, niacin, and the neurotransmitter serotonin. Inflammation causes tryptophan to be reallocated from serotonin synthesis to that of kynurenine, which then converts to the neurotoxin quinolinic acid, leading to depression. Dietary sources of tryptophan include most protein-based foods, such as meat, beans, or nuts.

Genes that suppress cell division or growth. Tumor suppressor genes encode proteins involved in aspects of cell growth regulation such as cell cycle arrest and apoptosis. Loss of tumor suppressor gene function promotes uncontrolled cell division and growth, which are hallmarks of cancer.

A metabolic disorder characterized by high blood sugar and insulin resistance. Type 2 diabetes is a progressive condition and is typically associated with overweight and low physical activity. Common symptoms include increased thirst, frequent urination, unexplained weight loss, increased hunger, fatigue, and impaired healing. Long-term complications from poorly controlled type 2 diabetes include heart disease, stroke, diabetic retinopathy (and subsequent blindness), kidney failure, and diminished peripheral blood flow which may lead to amputations.

A fat-soluble vitamin. Vitamin A is a collective term that includes retinol, retinal, and retinyl esters. Vitamin A plays key roles in immune function, reproduction, and cellular communication. It is best known for its role in supporting eye health and the processes involved in vision. Vitamin A also supports cell growth and differentiation and participates in the normal formation and maintenance of the heart, lungs, kidneys, and other organs. Dietary sources of vitamin A include liver, fish oils, milk, eggs, leafy green vegetables, orange and yellow vegetables, tomato products, fruits, and some vegetable oils.

Thiamine is a water-soluble B-vitamin, also known as vitamin B1, and a cofactor for enzymes involved in the breakdown and metabolism of carbohydrates, certain amino acids, and fatty acids. These enzymes help to generate energy in the form of ATP and modulate levels of amino acids that can cause deleterious effects. Thiamine is highly water soluble and is not retained in the body. For this reason, it must be continually obtained from the diet. Dietary sources of thiamine include vegetables, whole grains, legumes, and pork livers. Deficiencies in thiamine result in neurological, muscular, and cardiac symptoms, and can occur in as little as 18 days of total dietary depletion.

A potent water-soluble antioxidant found in citrus fruits. Vitamin C is an essential nutrient involved in tissue repair, neurotransmission, and immune system function. Also known as ascorbic acid.

A fat-soluble vitamin stored in the liver and fatty tissues. Vitamin D plays key roles in several physiological processes, such as the regulation of blood pressure, calcium homeostasis, immune function, and the regulation of cell growth. In the skin, vitamin D decreases proliferation and enhances differentiation. Vitamin D synthesis begins when 7-dehydrocholesterol, which is found primarily in the skin’s epidermal layer, reacts to ultraviolet light and converts to vitamin D. Subsequent processes convert D to calcitriol, the active form of the vitamin. Vitamin D can be obtained from dietary sources, too, such as salmon, mushrooms, and many fortified foods.

A type of fat-soluble vitamin that participates in blood clotting and bone metabolism. Naturally occurring forms of vitamin K include phylloquinone (vitamin K1) and a family of molecules called menaquinones (vitamin K2). Vitamin K1 is synthesized by plants and is the major form present in the diet. Vitamin K2 molecules are synthesized by the gut microbiota and found in fermented foods and some animal products (especially liver). The body has limited vitamin K storage capacity, so the body recycles it in a vitamin K redox cycle and reuses it multiple times.

A type of fat-soluble vitamin. Vitamin K is critical for blood clotting, bone metabolism, prevention of blood vessel mineralization, and regulation of various cellular functions. Naturally occurring forms of vitamin K include phylloquinone (vitamin K1) and a family of molecules called menaquinones (vitamin K2). Vitamin K1 is synthesized by plants and is the major form in the diet. Vitamin K2 molecules are synthesized by the gut microbiota and found in fermented foods and some animal products (especially liver). The body has limited vitamin K storage capacity, so the body recycles it in a vitamin K redox cycle and reuses it multiple times.

A type of fat-soluble vitamins that participate in blood clotting and bone metabolism. Naturally occurring forms of vitamin K include phylloquinone (vitamin K1) and a family of molecules called menaquinones (vitamin K2). Vitamin K1 is synthesized by plants and is the major form in the diet. Vitamin K2 molecules are synthesized by the gut microbiota and found in fermented foods and some animal products (especially liver). The body has limited vitamin K storage capacity, so the body recycles it in a vitamin K redox cycle and reuses it multiple times.

An anticoagulant drug, commonly sold as Coumadin. Warfarin is used to prevent blood clots from forming or growing larger in the blood and blood vessels. It works by inhibiting vitamin K-dependent coagulation factors. Warfarin is prescribed for people who have experienced or are at risk of experiencing atrial fibrillation, cardiac valve replacement, or myocardial infarction (heart attack). Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants, often commonly referred to as "blood thinners."

A foreign substance that is introduced into the body from the environment and is subsequently metabolized. Xenobiotics can exert multiple effects (good or bad) on the body by disrupting or interacting with cellular communication pathways that regulate growth, development, and normal physiological function. They are subject to extensive biotransformation in the human body via Phase 1 and Phase 2 metabolism, with a goal toward elimination. Examples of xenobiotics include drugs, pollutants, and plant-based dietary compounds.