At Arivale, we deploy cutting edge science to turn your data into specific, actionable recommendations to help optimize your wellness. However, this scientific path is filled with complex words and abbreviations you may not have heard before.
As you read through your coach handouts and reports, use this glossary as a guide to better understand unfamiliar terms. Keep in mind that your Arivale Coach will also be there every step of the way to explain this information in greater detail—because success is never a solo endeavor.
Note: Arivale’s Scientific Wellness Glossary is a continuous work in progress. If you notice a term missing from this resource, please contact the Arivale concierge line at (206) 981-5834 or email firstname.lastname@example.org, and we will add your suggestion to the Glossary.
A/G Ratio: A ratio that reflects the amount of albumin in blood compared to globulin. A normal A/G ratio is slightly over 1 and reflects liver and kidney health.
Absolute Basophils Count: The amount of basophils in the blood calculated as the amount of total white blood cells (WBCs) multiplied by the percent of basophils.
Absolute Eosinophils Count: The amount of eosinophils in the blood calculated as the amount of total white blood cells (WBCs) multiplied by the percent of eosinophils.
Absolute Lymphocytes Count: The amount of lymphocytes in the blood calculated as the amount of total white blood cells (WBCs) multiplied by the percent of lymphocytes.
Absolute Monocytes Count: The count of monocytes in the blood found by multiplying the total white blood cells (WBCs) by the percent of those cells that are monocytes.
Absolute Neutrophils Count: The amount of neutrophils in the blood calculated as the amount of total white blood cells (WBCs) multiplied by the percent of neutrophils
ACE: The ACE gene codes for the angiotensin-converting enzyme (ACE), which affects blood pressure by regulating the volume of fluids in the body.
Achilles tendinopathy: A combination of Achilles tendon pain, swelling and stiffness that reduces your ability to participate in physical activity. The Achilles tendon attaches the muscles in the back of your lower leg to your heel. Tendons attach muscle to bone or other structures.
Adiponectin: A hormone secreted from fat cells, involved in blood sugar regulation.
Alanine Transaminase: An enzyme mainly found in the liver. It is a commonly measured marker for liver health.
Albumin: The most abundant protein found in the blood. One of its major jobs is to regulate the exchange of water between the blood and the spaces between the cells. It is also a transport protein for a variety of molecules in the blood as well as certain drugs.
Alkaline Phosphatase (ALP): ALP is a protein found in all body tissues. The liver, bile ducts and bone have higher amounts. ALP is used as a liver function test.
Allele: One of two or more versions of a gene. An individual inherits two alleles for each gene, one from each parent. If the two alleles are the same, the individual is considered “homozygous” for that gene. If the individual has two different alleles for a certain gene, they are considered “heterozygous.”
AGT: AGT is a gene that codes for the angiotensin protein. Angiotensin is expressed in tissues involved in blood pressure regulation such as the kidneys, adrenals and brain. Levels of this protein are associated with blood pressure.
Analyte: A substance or material determined by chemical analysis. Measured lab values are considered to be analytes.
Anterior cruciate ligament rupture (ACL): A partial or full tear of the ACL ligament, one of the many ligaments connecting the upper and lower portions of the leg at the knee. A ligament connects bone to bone.
Antioxidants: Substances that remove potentially damaging oxidizing agents are called free radicals. Antioxidants are found naturally in the body in the form of enzymes, but can also be consumed in a wide variety of foods. Vegetables and fruits, spices, herbs, as well as green tea and red wine are high in antioxidants.
Apolipoprotein C3 (APOC3): The APOC3 gene codes for a protein called APOC3, which plays an important role in cholesterol metabolism. The APOC3 protein inhibits the breakdown of fat-rich particles in the blood and liver.
Arachidonic Acid: A type of omega-6 fat. This fat is commonly found in meat, eggs, and dairy. It is not an essential fatty acid, meaning the body can produce it on its own.
Arachidonic Acid/EPA: Ratio of arachidonic acid (omega-6) to EPA (omega-3).
Arivale Coach: Registered Dietitian Nutritionist (RDN) or Registered Nurse (RN) who works with a client on a regular basis. The coach is responsible for translating the complex scientific information from physician-ordered laboratory tests into actionable recommendations, to help the client optimize his or her wellness and help meet their wellness objectives.
Artificial Trans Fats: Type of fat created by industrial processing of food. Trans fats have been associated with a number of health risks, including increased LDL cholesterol, and increased diabetes risk. that. These fats are made when vegetable oils are or partially hydrogenated. Examples include fried foods, baked goods, frozen foods and margarine.
Aspartate Transaminase: An enzyme present in tissues of high metabolic activity (heart, liver, muscle, brain, etc.). It is released into the blood after injury or damage to cells. Used as a marker of liver function.
B Vitamins: B vitamins provide building blocks for growing cells, and play an important role in many physiological processes. B vitamins also supply some of the chemicals necessary for protecting our genes, so that our DNA doesn’t accumulate as much damage from the wear and tear in the daily lives of our cells. These vitamins—including folate, vitamins B6 and B12—help make new DNA for cells that are constantly growing and renewing themselves.
Basophils: A type of white blood cell involved in certain kinds of inflammatory or allergic reactions.
Bilirubin: Bilirubin is the yellow-ish breakdown product of normal blood cell metabolism. It is excreted in bile and urine.
BUN: BUN stands for Blood Urea Nitrogen. It is a measurement of the amount of nitrogen in the blood that comes from the waste product urea.
Calcium (Total or Free): Measurement indicating both amounts of circulating and bound calcium in the blood. Does not reflect the levels of calcium in the bone.
Calcium Homeostasis: Refers to the very tight regulation of calcium ions in the blood.
Carbon Dioxide: Gaseous waste product from metabolism. Measuring levels of bicarbonate in the blood, which is the chemical (buffer) that keeps the pH of blood balanced.
Catechol-O-Methyl-Transferase (COMT): The COMT gene codes for the COMT protein, which is involved in methylation and helps control the levels of certain estrogenic hormones. Higher levels of this protein may help reduce DNA damage. The COMT protein is also involved in the breakdown of certain neurotransmitters and has been related to both emotional and cognitive functioning.
Cholesterol Esther Transfer Protein (CETP): This gene codes for the enzyme CETP, which plays a key role in the metabolism of HDL (“good”) cholesterol. Chloride: Important electrolyte in the blood. It helps maintain proper cellular fluid balance, blood volume, blood pressure and pH of body fluids.
COL1A1: The COL1A1 gene encodes for a protein called Type 1 collagen. Type 1 collagen is the major protein of bone.
Connective Tissue: Tissue that connects, supports or separates other tissues or organs. Examples include tendons, cartilage and ligaments.
Cortisol: A stress hormone secreted by the adrenal glands. Elevations in cortisol can be an indicator of chronic stress. Consistently high cortisol has been associated with increased risk for a number of diseases, including diabetes, obesity, and heart disease.
C-Reactive Protein (CRP): Substance formed by the liver in response to inflammation. A higher level CRP indicates that the body is in a more inflamed state. Also called “hs-CRP” or “high-sensitivity CRP,” referring to the type of lab analysis that is performed.
Creatinine: A chemical waste molecule that is generated from muscle metabolism. The kidney filters this from the blood into the urine, making it a good marker for kidney function.
Cystathionine Beta Synthase (CBS): The CBS gene codes for an enzyme involved in removing homocysteine from its biochemical cycle. This can result in elevated blood levels of homocysteine if B-vitamin intake is inadequate.
CYP1A1: The CYP1A1 gene codes for an enzyme that converts environmental toxins to reactive molecules that can contribute to the development and growth of cancer, especially in smokers. In addition, CYP1A1 is involved in the metabolism of estrogens.
Detoxification: Detoxification involves a number of processes in the body that remove harmful substances (toxins). Your body detoxifies both environmental toxins and those generated as a natural byproduct of your body’s metabolism.
DHA: A type of omega-3 fat, which has been associated with reduced inflammation, and improved brain and cardiovascular health. This fat is essential and cannot be synthesized by the body. It must be consumed via diet.
Dietary Fiber: The parts of vegetables, whole grains, fruit, legumes, and nuts that cannot be digested by humans. There are two types of dietary fiber, soluble and insoluble. Most fiber-rich foods contain both types of fiber, with one type predominating over the other.
Endothelium-Derived Nitric Oxide (eNOS): Plays a key role in the regulation of blood vessel tone and helps protect blood vessels.
Eosinophils: A type of white blood cell that functions in allergic responses and to help resist infections.
FADS1 (Fat metabolism): The enzyme encoded by the FADS1 gene is important in polyunsaturated fatty acid (PUFA) metabolism. Variants in the FADS gene have been associated with blood concentrations of long-chain PUFAs as well as with cholesterol concentrations.
Fat-Mass-and-Obesity-Associated (FTO): The FTO gene is present in high levels in metabolically active tissues like heart, kidney and brain. Variants in FTO are associated with increased obesity risk, especially in an environment of highly processed/fatty foods and low exercise. The FTO gene may play a role in appetite regulation and be associated food intake and sense of fullness.
Ferritin: An iron-containing protein that serves to store iron in the tissue.
Folate: A B-vitamin that is involved in turning many genes on and off, and also helps repair DNA. “Folic acid” is the synthetic form of folate found in many dietary supplements and fortified foods.
Free Radical: Free radicals are atoms or groups of atoms with an odd (unpaired) number of electrons and can be formed when oxygen interacts with certain molecules. They can damage cellular membranes and DNA. To prevent free radical damage, the body has a defense system of antioxidants.
Gamma-Glutamyl Transpeptidase (GGT): A transport molecule involved in helping the liver metabolize drugs and toxins. Serves as a marker for liver function. GGT has also been associated with risk factors for diabetes.
Gene: A segment of the DNA molecule that contains the instructions by which your body makes each of the many thousands of proteins required for life. Each gene is comprised of thousands of combinations of adenine (A), thymine (T), cytosine (C), and guanine (G), which make up your genetic code. Each gene code combines the “letters” A, T, C and G in various ways. These “letters” spell out the “words” that specify which amino acid is needed to make the proteins required for proper development and function.
Gene Variations: Slight changes in the genetic code. For example, one genetic “letter” (A, T, C, or G) may be replaced by another. These variations can lead to different bodily processes, just as altering one letter in a word can change its meaning. Gene variations can have beneficial effects, harmful effects or, not uncommonly, no effect at all. All individuals have multiple gene variants in their DNA.
Genotype: An individual’s specific gene sequence.
Globulin: One of the major proteins in blood, produced by the liver and the immune system. Globulin proteins help transport iron in the blood and may be involved in fighting infections.
Glomeruli: Tiny filters in the kidneys that filter waste from the blood.
Glomerular Filtration Rate (GFR): Measures the amount of blood passing through the glomeruli each minute and is a measure of kidney function. The result is based on the creatinine level and several other factors including age, ethnicity, gender, height, and weight.
Glucose (blood): A simple sugar that is an important energy source in living organisms. Otherwise known as blood sugar.
Glutathione (GSH): A potent natural antioxidant that helps prevent cellular oxidative damage.
GSTM1: The GSTM1 gene codes for the Glutathione S-transferase M1 protein, the most biologically active member of the GST superfamily. GSTM1 is involved in Phase II detoxification in the liver. It is responsible for removing environmental pollutants as well as internal toxins related to oxidative stress.
GSTP1: The GSTP1 gene codes for GSTP1, the most abundant GST enzyme in the lungs. GSTP1 enzyme helps metabolize airborne toxins and pollutants. The efficiency of the GSTP1 enzyme also has an impact on the development and prognosis of diseases influenced by oxidative stress (e.g. heart disease and cancer).
GSTT1: This gene codes for GSTT1, a member of the GST enzyme family (a superfamily of proteins involved in detoxification). It plays an important role in multiple aspects of detoxification.
Gut Microbiome: Collectively refers to all the bacteria in your gut. There is a consensus among scientific and medical experts that the gut is very important for human health. Research on the gut microbiome is still in its infancy.
HDL: High-density lipoprotein is a well-behaved cholesterol molecule; involved in removing undesirable cholesterol from where it doesn’t belong.
HDL-P (Total): A total number of particles of all the HDL particle sizes.
Health Dimensions: The organized systems analyzed by Arivale. Each Health Dimension integrates data from clinical lab results, genetics and lifestyle or traits.
Hematocrit (HCT): Measures the percentage of whole blood that is made up of red blood cells (RBCs). This result will depend on the number and size of RBCs.
Hemoglobin: A protein in red blood cells that carries oxygen to the tissues.
Hemoglobin A1C: A measure in blood that reflects average blood sugar levels over three months. Also called “glycated hemoglobin”.
Hereditary Hemochromatosis: A genetic disorder in which there is an excessive accumulation of iron in the body, leading to iron overload. In individuals with the disorder, the daily absorption of iron from the intestines is greater than the amount needed to replace losses. Since the normal body cannot increase iron excretion, the absorbed iron accumulates in the body. Individuals who carry the genes for hereditary hemochromatosis may have no symptoms, and the disease is treatable if detected early. Severe symptoms and signs of iron overload include sexual dysfunction, heart failure, joint pains, liver disease, diabetes , fatigue, and dark skin pigmentation.
Heterozygous: See “Allele.”
HOMA-IR (Calculated): Measure of insulin resistance (the body’s ability to use insulin to reduce blood sugar). HOMA-IR is calculated from the fasting blood glucose and insulin values using an equation that has been validated against other, more invasive, measures of insulin resistance.
Homocysteine: An amino acid and breakdown product of proteins, associated with increased heart disease risk.
Homozygous: See “Allele.”
Hs-CRP: See “C-reactive protein.”
HFE: This gene encodes a protein that regulates iron absorption. Multiple variants in the HFE gene have been associated with hemochromatosis (an iron overload disease). Men and postmenopausal women who carry this genetic variant are at greater risk for the disease.
Indirect Bilirubin: Insoluble form of bilirubin. It travels through the blood to the liver, where it is changed into a soluble form.
Inflammation: Acute inflammation is a normal immune response and an essential step in tissue healing. However, chronic inflammation is not beneficial. An increasing number of common disorders, such as obesity, heart disease, arthritis and inflammatory bowel disease have been associated with chronic low-grade inflammation.
Insoluble Fiber: Insoluble fiber does not soak up water. This type of fiber acts like a broom that sweeps through the colon, and aids in elimination and bowel regularity.
Insulin: A hormone that stimulates the uptake of glucose from the diet into the blood. Those with lowered sensitivity to insulin have a limited ability to respond to the hormone’s action.
Insulin Resistance (IR): The body’s ability to use insulin to reduce blood sugar. Insulin insensitivity or resistance may play an important role in some of the most common disorders—including, obesity, type 2 diabetes, high blood pressure, heart disease and disrupted fat metabolism.
Interleukin 6 (IL-6): A pro-inflammatory chemical that plays a crucial role in inflammation and regulates expression of C-reactive protein. (Low-grade chronic inflammation is associated with obesity and visceral fat deposition, insulin resistance, dyslipidemia and increased risk for cardiovascular disease.
Lead: Heavy metal toxin.
Legumes: Type vegetable that includes beans, peas and lentils.
Leptin: A hormone produced by fat cells that is involved in regulating body fatness. Leptin’s main effect in this regard is to produce feelings of fullness. Leptin levels usually drop after weight loss, which can lead to increased hunger drive.
LPL: This gene codes for a protein called lipoprotein lipase (LPL). The LPL enzyme removes lipids (fats) from the blood.
LDL: Low-Density Lipoprotein, or “bad” cholesterol molecule which contributes to plaque deposits that can clog arteries and make them less flexible.
LDL-P (Total): The number of particles of LDL. LDL particles carry both triglyceride and cholesterol, and are associated with heart disease risk.
LDL Size: Large-sized LDL are the least damaging of all the LDL sizes. A greater LDL size is favorable and decreases heart disease risk.
LpPLA2: An inflammatory marker/enzyme that accelerates the formation of plaque in the blood vessels.
Magnesium, Serum: A trace mineral involved in a multitude of actions in the body. Serum magnesium is not always indicative of total magnesium, as most of the body’s magnesium is stored in the bones.
MCM6: Decreased ability to digest lactose, a sugar common in dairy products, can be due to a decline in a digestive enzyme called “lactase.” Activity of this enzyme is influenced by genetic factors.
Mean Corpuscular Hemoglobin (MCH): An estimate of the amount of hemoglobin in an average RBC. The MCH is elevated when RBCs are too large and is decreased when RBCs are too small.
Mean Corpuscular Hemoglobin Concentration: A calculation of the average concentration of hemoglobin inside a single RBC. It is calculated by dividing hemoglobin by hematocrit.
Mean Corpuscular Volume (MCV): The average volume of RBCs. A low MCV indicates a small average RBC size, whereas a high MCV indicates a large average RBC size. Immature (young) RBCs tend to be larger than more mature cells.
Mercury: A heavy metal toxin. High levels of mercury can be found in some fish and in dental amalgams.
Metabolic Equivalent Task (MET): A way to measure how much energy you burn during any chosen physical activity. Every activity, from watching TV to going for a run, has a MET value. The more vigorous the activity, the higher the MET value.
MET HOURS: A calculated measure of the total energy expended during physical activity. To calculate, take the MET value for a specific physical activity and multiply it by the duration (in hours).
Methionine: An essential amino acid required for protein synthesis.
Methionine Synthase (MTR): Encodes the enzyme that catalyzes the remethylation of homocysteine to methionine. Homocysteine levels are associated with risk for heart disease and some cases of depression.
Methionine Synthase Reductase (MTRR): An enzyme involved in the synthesis pathways for methionine, an essential amino acid required for protein synthesis, and methionine synthase, which is important for maintaining normal homocysteine levels.
Methylation: A chemical process involving the addition of “methyl groups”. Methylation is critically important for a large number of functions in the body, including immune function, energy production, detoxification, mood balancing and minimizing DNA damage. Methylation is impacted by both genetics and the environment.
Methylenetetrahyrdofolate Reductase (MTHFR): A key enzyme involved in the metabolism of the B vitamin folate. Folate levels influence blood levels of homocysteine, which is associated with heart disease risk and some cases of depression.
Methylmalonic Acid (MMA): A marker of vitamin B12 status
Microbiome: See “Gut Microbiome”
MnSOD/SOD2: See “SOD2.”
Monocyte: Large phagocytic white blood cells.
Neutrophil: The most abundant of all white blood cells. Formed by the stem cells in the bone marrow.
NOS3: Plays a key role in the regulation of blood vessel tone. It also protects the blood vessels by multiple physiological actions.
Nucleotide: The building blocks of DNA/RNA – can be A,G,T or C.
Nutrigenetics: The science of the effects of individual genetic variations in response to diet, exercise and lifestyle. Each of these environmental factors can cause genes to be “expressed” in a positive or negative way. Nutrigenetic testing enables us to identify key areas to help achieve an individual’s optimal health.
Omega-3 Index: Ratio of omega 3 fatty acids to total fatty acids.
Omega-3 Polyunsaturated Fats: Omega-3 fats include EPA and DHA, which can help raise HDL, lower LDL, and reduce inflammation. Food rich in these fats include cold-water fish like salmon or tuna, flax seeds and walnuts.
Omega-6/Omega-3: Ratio of omega-6 to omega-3 fatty acids
Oxidative Stress: The damage that results from free radicals that are generated during the breakdown of oxygen molecules. The key to neutralizing these free radicals is to increase antioxidant levels.
PPARG: This gene codes for a protein called Peroxisome Proliferator-Activated Receptor Gamma. PPARG protein is a transcription factor activated by fatty acids. It is also involved in the regulation of glucose and lipids in the blood and is the target for certain diabetes medications.
Phosphorus: A mineral in the blood that helps build bones and teeth, important for nerve signaling and muscle contraction.
Pioneer: Arivale clients who are paving the path to the future of wellness.
Platelet Count: Platelets are cell fragments necessary for blood clotting.
Polygenic Profile: The term “polygenic” simply means “many genes.” Your polygenic profile is the sum of the effects of all the common genetic variants implicated for a quantitative trait or complex disorder that are observed within you. These common variants typically have smaller effects than rare variants, but the sum of these effects can be quite significant.
Potassium: An electrolyte and mineral in the blood. It helps keep the water and electrolytes balance of the body. Important in nerve, muscle and kidney function.
Prehabilitation: Injury prevention strategies are also called prehabilitation. Opposite of rehabilitation which is for after an injury, prehabilitation is to prevent injury. Resistance and flexibility training are the cornerstones for prehabilitation. Examples include progressive strength training, Pilates, and yoga.
Pro-Oxidant: A substance that encourages oxidation in the body.
Red Blood Cell Distribution Width: A calculation of the variation in RBC sizes. An elevation in this lab indicates a large variation in RBC size and may be the result of iron deficiency or pernicious anemia.
Reference Genome: The reference genome is released by a research consortium in the scientific community (Genome Reference Consortium at NCBI). It is the currently accepted reference version (on version 38 now) of the human genome and is used to compare against the genome being tested. Note that the GRC is focused on many genomes, not just the human one. This means it is a source that can be used to understand other genomes through comparisons. It does not represent a single person but rather a combination of several people. It does not represent the ‘perfect’ or ‘ideal’ genome. It is constantly under revision as there are still regions in the human genome which are uncertain.
Refined Polyunsaturated Omega-6 Fat: Refined omega-6 fats have been associated with increased inflammation and are missing the nutrients and fiber from the whole foods source that support a healthy system.
Saturated Fat: In excessive quantities saturated fat has been shown to clog and stiffen arteries, increasing the risk of developing heart disease. They also cause insulin resistance, which increases the risk for developing diabetes, and can increase inflammation. These fats are primarily found in animal products such as meat, dairy, cheese, as well as some plant products such as coconut oil and palm oil.
Segmented Neutrophils: Neutrophils that are mature and have at least two distinct lobes in the nucleus giving them a segmented appearance.
Scientific Wellness: A new industry launched by Arivale that utilizes an individual’s unique genetic makeup, clinical lab data and lifestyle to optimize wellness.
SLC2A2: SLC2A2 facilitates the first step in glucose-induced insulin secretion in the pancreas. SLC2A2 has been suggested as a glucose sensor, is considered to be important in regulating blood sugar after meals, and is involved in food intake and regulation.
Small LDL-P: Small-sized LDL particles are the most detrimental type of LDL. When present in excess, these small particles contribute to increased heart disease risk.
SOD2: The SOD2 enzyme destroys the free radicals which are normally produced within cells and which are damaging to biological systems. The enzyme thus has important antioxidant activity within the cell, especially within the mitochondria.
SOD3: SOD3 is the extracellular form of the SOD enzyme, and the major antioxidant enzyme system in blood vessel walls.
Sodium: An electrolyte and mineral in the blood. It helps keep the water and electrolytes balance of the body. Important in nerve and muscle function.
Soluble Fiber: Soluble fiber has the ability to soak up water. It stimulates the muscles in your intestines and binds to cholesterol and toxins allowing them to be eliminated from the body. Soluble fiber increases the feeling of fullness after eating a meal, and is helpful for lowering cholesterol, improving blood sugar balance, maintaining a healthy weight, and promoting the growth of friendly bacteria in the gut.
TG/HDL Ratio: Ratio of triglycerides to HDL cholesterol.
Total Bilirubin: This substance is found in bile and produced when the liver breaks down old red blood cells.
Total Cholesterol: A fat-like substance that’s found in all cells of the body used to make hormones, vitamin D, and materials that help you digest foods.
Total Protein: Measurement of the total amount of protein in the blood (including both Albumin and Globulin).
Transcription Factor 7-like 2 (TCF7L2): Gene that encodes a protein that regulates blood glucose (sugar). Variants in this gene influence both insulin secretion and insulin sensitivity and have been associated with Type 2 diabetes risk.
Triglycerides: A type of fat found in the blood that is an important indicator of heart health. It is made from excess caloric intake that can’t be processed by the body right away.
Tumor Necrosis Factor-α (TNF α): This gene encodes the TNFα protein. TNFα is a pro-inflammatory chemical that is secreted by both immune cells and fat cells. It has been shown to alter blood sugar regulation and has been implicated in the development of obesity, insulin resistance and abnormal blood cholesterol.
Unrefined Monounsaturated Fats: Heart-healthy food options that may help raise HDL and lower LDL to help reduce the risk of developing heart disease. Examples include olives, olive oil, avocado, nuts, and seeds.
Unrefined Omega-6 Polyunsaturated Fats: While omega-6 fats are often considered pro-inflammatory, the whole food sources contain phytochemicals and fiber that support reduced cholesterol and reduced inflammation. Examples include nuts and seeds.
Urea: Product made when protein is broken down in the body. Made in the liver and passed out of the body in the urine.
Vitamin D/25-OH: A measure of vitamin D levels.
Vitamin D Receptor (VDR): Gene that accounts for a large amount of the genetic influence on bone density, playing an important role in calcium balance, bone cell growth and differentiation, and intestinal calcium absorption.
Zinc: A trace mineral involved in immune function and DNA synthesis.