Nutrients

The active folate form involved in methylation, homocysteine metabolism, DNA synthesis and nervous-system function. It differs from folic acid because it is already in a biologically ready form and does not require several conversion steps.

This mitochondrial coenzyme form of vitamin B12 supports conversion of methylmalonyl-CoA to succinyl-CoA; its importance is seen in energy metabolism, nerves, and the methylmalonic acid marker.

A plant-based essential Omega-3 fatty acid found in flax, chia, walnuts and some oils. It supports membrane lipid balance and can be converted to EPA and DHA only to a limited extent, so it should not be treated as a full replacement for marine or algae-derived long-chain Omega-3s.

A linear fraction of starch that affects granule density, digestive speed, and the amount of resistant starch. In low-carb nutrition, amylose matters as a way to understand why different starch sources can affect glucose, satiety, and tolerance differently.

A long-chain Omega-6 fatty acid from animal foods and cell membranes. It gives rise to eicosanoids, so the practical issue is not a slogan about “bad Omega-6”, but inflammatory context, diet quality, EPA/DHA status and excess refined seed oils.

The ionized form of vitamin C and mineral salts of ascorbic acid are often gentler on the stomach, but ascorbate choice still requires attention to total dose, added minerals, and kidney stone risk in susceptible people.

This water-soluble vitamin is needed for collagen, immune function, antioxidant defense, and non-heme iron absorption; deficiency is harmful, but high doses do not turn vitamin C into a universal treatment.

An orange-yellow carotenoid and plant provitamin A. It can be converted into retinol, but efficiency depends on dietary fat, bile, gut function, genetics, vitamin A status and the overall diet.

A water-soluble B7 vitamin required by enzymes of fat, carbohydrate, and amino acid metabolism; high-dose supplements also matter because they can distort laboratory tests.

The umbrella name for vitamin D forms, including D2 and D3, is linked with calcium and phosphorus metabolism, bones, immune regulation and muscle function. Practical use depends on 25(OH)D level, dose, magnesium, vitamin K2, kidney function, sun exposure and excess risk.

Organic compounds that include glucose, fructose, galactose, starch, sucrose, lactose and different fibers. For keto, the important issue is not only grams of carbohydrate, but also form: sugar, starch, fiber, polyols, processing level and blood-glucose response.

A compound involved in transporting long-chain fatty acids into mitochondria, carnitine matters for energy metabolism, heart, muscle and liver function. Supplements are not automatic fat burners; effects depend on deficiency, form, dose, diet, training and mitochondrial context.

A nutrient required for liver fat export, bile, cell membranes, acetylcholine, and methylation; intake matters especially in pregnancy, fatty liver, and diets without eggs, liver, and fish.

An amino acid linked to the urea cycle and arginine synthesis; supplemental forms are mainly used for nitric oxide, blood flow, training performance, and ammonia handling.

Vitamin B12 is needed for the nervous system, red blood cell formation, methylation and fatty acid metabolism. Deficiency is often linked not to low-carbohydrate eating itself, but to poor absorption, vegan diets, age, metformin, proton pump inhibitors, autoimmune gastritis and stomach or intestinal surgery.

Polysaccharides and longer carbohydrate chains: starch, glycogen and different dietary fibers. Chemical complexity does not automatically make a food low-carb; bread, grains and potatoes can raise glucose quickly, while fiber and resistant starch behave differently.

A stable synthetic form of vitamin B12 used in supplements and injections; it must be converted into active B12 forms and matters most when deficiency risk is present.

A long-chain Omega-3 fatty acid that is especially important for the brain, retina, pregnancy, lactation and early development. DHA comes mainly from fatty fish, seafood and microalgae oil; conversion from plant ALA is limited, so the source needs to be chosen deliberately.

A marine long-chain Omega-3 fatty acid closely linked with eicosanoids, resolution pathways and triglyceride metabolism. EPA comes from fatty fish, seafood, fish oil and some algae products; it should not be confused with DHA, which has a stronger structural role in the brain and retina.

Minerals and ions that carry electrical charge and regulate water, blood pressure, nerves, muscles, heart rhythm and acid-base balance. On keto, sodium, potassium and magnesium are often most noticeable, but they should not be taken blindly, especially with kidney or heart disease, diuretics or blood pressure medications.

A dietary macronutrient that provides energy, helps absorb fat-soluble vitamins, supports bile flow, hormonal context and food flavor. On keto, fats matter, but quality, tolerance and fatty-acid balance are just as important as the amount.

The synthetic form of vitamin B9 is needed for DNA synthesis, blood formation, and proper cell division, and is especially important during pregnancy and the risk of folate deficiency. However, folic acid is not automatically equivalent to natural dietary folates, and its excess can mask a deficiency of B12, so it is useful to evaluate it alongside diet, tests, and clinical objectives.

Short fructose chains that act as prebiotic fiber and can feed bifidobacteria. In low-carb eating, fructooligosaccharides matter because sweetness, gut tolerance, serving size, and actual label carbohydrates do not always point in the same direction.

A simple monosaccharide naturally found in fruits, berries, honey, some vegetables, and as part of sucrose. In whole foods it comes together with water, fiber, organic acids, polyphenols, and minerals, so its effect differs from isolated fructose in syrups, juices, and sweet drinks.

An Omega-6 fatty acid supplied mainly by evening primrose, borage and blackcurrant seed oils. Its relevance comes from its conversion toward DGLA and signaling mediators, so supplements should be judged by goal, tolerance, medications and the whole fatty-acid pattern.

Amino acids whose carbon skeletons can be used to make glucose; this is normal metabolism and not a reason to fear protein on keto.

A mild organic acid formed from glucose oxidation is used in foods as an acidity regulator, chelator and technological ingredient. In nutrition, the practical meaning depends on the salt form, dose, product matrix, tolerance and the full composition of the finished product.

The main blood sugar and a fast energy source for tissues that require glucose. In keto, the issue is not glucose as a molecule, but chronic excess, large post-meal spikes, insulin resistance and the body’s ability to maintain normal levels without constant sugar intake.

A conditionally essential amino acid is especially important for the gut lining, immune cells, nitrogen metabolism and recovery after illness or heavy stress. Supplements are most useful when needs are increased and tolerance is good, not as a universal gut repair cure.

A group of proteins found in cereal crops, primarily in wheat, rye, and barley. It is responsible for the structure of dough, its elasticity, and the ability to retain gas during fermentation.

The stored form of glucose in the liver and muscles, supporting blood sugar stability, muscle work, and training adaptation. In low-carb nutrition, glycogen explains early water loss, electrolyte needs, and changes in exercise tolerance.

Lipoprotein particles involved in reverse cholesterol transport, anti-inflammatory protection and endothelial function. HDL-C in a blood test shows cholesterol carried inside HDL particles, but it does not always reflect their quality or function.

A medicinal form of vitamin B12 used for cobalamin deficiency and some poisonings; it requires understanding the cause of deficiency, not only injections based on fatigue.

A vitamin-like compound involved in cell signaling, insulin sensitivity, ovarian function, nervous-system activity and fat metabolism. Myo-inositol and D-chiro-inositol are discussed most often, especially in PCOS and insulin resistance.

Milk sugar made of glucose and galactose. For keto, the important questions are the lactose amount in a specific product and lactase tolerance: milk is usually more carbohydrate-rich than hard cheese, while fermented products may work better, but not for everyone.

This mixture of phospholipids, especially phosphatidylcholine, participates in cell membranes, choline metabolism, fat transport and bile function. In food it comes from eggs, liver, soy and sunflower; as a supplement it can act as an emulsifier or phospholipid source, but it does not replace treatment for liver or gallbladder disease.

An essential Omega-6 fatty acid that must be obtained from food, but modern diets usually provide too much rather than too little. The practical issue is not banning linoleic acid, but reducing excess refined seed oils and keeping balance with EPA/DHA.

A broad class of fat-like molecules: triglycerides, phospholipids, cholesterol, fatty acids and their derivatives. In food they provide energy, while in the body they build membranes, travel in lipoproteins and appear in blood tests as part of metabolic risk assessment.

LDL particles carry cholesterol and other lipids to tissues, but vascular risk is driven mainly by excess ApoB-containing atherogenic particles. LDL-C shows the mass of cholesterol inside LDL, not particle number; on keto, marked rises in LDL and ApoB require assessment of diet, genetics, thyroid status and overall risk rather than reassurance from high HDL alone.

Minerals needed in relatively large amounts: sodium, potassium, magnesium, calcium, phosphorus, chloride and sulfur. In low-carb eating, sodium, potassium and magnesium become especially noticeable because lower insulin changes water and salt retention.

A form of vitamin K2 connected with calcium metabolism, blood clotting, bone tissue and the arterial wall. Menaquinones differ by side-chain length; MK-4 and MK-7 are discussed most often, but their effects and sources are not identical.

This active coenzyme form of vitamin B12 participates in methylation, homocysteine metabolism and nervous system support. It can be a useful supplement form in B12 deficiency, but the choice between methylcobalamin, cyanocobalamin, hydroxocobalamin and adenosylcobalamin depends on the cause of deficiency, absorption, symptoms and tolerance.

Mineral elements needed in small amounts but critical for enzymes, thyroid function, blood, immunity and antioxidant defense. They include iron, zinc, copper, selenium, iodine, manganese, molybdenum, chromium and others; for many of them excess can be as harmful as deficiency.

A form of vitamin B3 needed to make NAD and NADP, coenzymes involved in energy metabolism, skin, nervous-system function, digestion and lipid metabolism. In supplements, nicotinic acid, nicotinamide and pharmacological doses must be distinguished.

A monounsaturated fatty acid characteristic of olive oil, avocado, almonds and many animal fats. It is not a medicine, but it can make a low-carb diet gentler for the lipid profile and more stable for cooking, especially when it replaces excess refined seed oils.

A family of fatty acids that includes ALA, EPA and DHA. Nutrition should distinguish plant and marine forms: flax and chia provide ALA, while fatty fish, seafood and microalgae provide EPA/DHA, which are directly linked with membranes, inflammatory mediators and triglycerides.

A family of fatty acids that includes linoleic, gamma-linolenic and arachidonic acids. Omega-6 fats are necessary, but modern diets often provide excess from sunflower, soybean and corn oils, deep-fried foods and industrial sauces while EPA/DHA intake is low.

An amino acid involved in the urea cycle, the liver system that detoxifies ammonia. Ornithine is connected with arginine, citrulline, protein metabolism and nitrogen handling, but supplementation makes sense only in specific contexts.

A monounsaturated Omega-7 fatty acid found in macadamia nuts, sea buckthorn oil, some fish fats and human adipose tissue. It is often discussed as a metabolic signal, but in practice the priority is overall fat quality rather than chasing separate capsules.

Vitamin B5 is required for coenzyme A formation and therefore participates in fatty acid metabolism, acetyl-CoA, steroid hormone synthesis, acetylcholine, and cellular energy production. Deficiency is uncommon, but poor diets, malabsorption, alcohol use, and long-term restriction can make its role clinically relevant.

Short amino acid chains may be fragments of dietary proteins, hormones, signaling molecules, or medicines. Their meaning depends on the exact structure, dose, route of administration, evidence, and purpose, not on the fashionable word “peptide” itself.

Salts of phosphoric acid and the form in which phosphorus participates in bone, ATP, phospholipids and buffering systems. Phosphorus from whole foods is necessary, but excess phosphate additives from processed foods and impaired kidney excretion require special attention.

A major membrane phospholipid and choline source important for liver fat export, bile composition, lipoproteins, acetylcholine, and cellular membranes.

A membrane phospholipid especially relevant to neurons, signaling, stress response, and cognitive function; supplemental forms require caution with anticoagulants, sleep problems, and complex medication use.

Vitamin K1 from green leafy vegetables, required for normal blood clotting and vitamin-K-dependent proteins. In people using warfarin or other vitamin K antagonists, the key is not eliminating greens but keeping intake stable.

The main structural macronutrient: amino acids form muscle, enzymes, immune proteins, transporters and many signaling molecules. In low-carb eating, protein should be regular and sufficient, but assessed by quality, tolerance, body size, activity and kidney, liver and digestive context.

Are organic compounds that are part of all cells in the body and participate in key metabolic processes. They are necessary for the synthesis of DNA and RNA, as well as for the formation of ATP — the universal energy molecule.

This form of vitamin B6 participates in amino acid metabolism, nervous system function, neurotransmitter synthesis, hemoglobin formation, and homocysteine handling. Food intake and high-dose supplementation should be separated clearly because excess B6 can cause neuropathy.

This active form of vitamin A is needed for vision, immunity, skin, mucous membranes, reproduction, and gene regulation. It is important to separate retinol from animal foods from plant carotenoids and to remember that high doses can be toxic, especially in pregnancy.

Vitamin B2 is required for FAD and FMN, coenzymes involved in energy metabolism, mitochondrial function, antioxidant defense, skin, mucous membranes, and activation of other B vitamins. Deficiency may cause mouth cracks, sore tongue, fatigue, and light sensitivity, but symptoms are nonspecific.

Sugars made of one or two sugar units: glucose, fructose, galactose, sucrose, lactose and maltose. They enter metabolism quickly, but their effect depends on dose, food matrix, liquid form, pairing with protein and fat, liver status and insulin sensitivity.

Ordinary table sugar: a disaccharide made of glucose and fructose. For keto, sucrose is problematic because it combines a fast glucose rise, fructose load on the liver, weak satiety and easy overconsumption in drinks, desserts, sauces and processed foods.

A sulfur-containing amino-acid-like molecule important for bile acids, the heart, retina, nervous system, electrolyte balance, and muscle function. It comes mainly from animal foods, while supplements should be considered separately from energy drinks and with attention to kidneys, medication, and blood pressure.

The active reduced form of folate that carries one-carbon units for DNA synthesis, methylation, homocysteine metabolism, and blood cell formation. Its function depends on vitamin B12, B6, riboflavin, enzyme activity, gut health, and medication context.

Vitamin B1 is required for converting carbohydrates and some amino acids into usable energy and for normal nerve, heart, and brain function. Alcohol, vomiting, bariatric surgery, diuretics, high carbohydrate load, severe illness, and nutrient-poor diets raise deficiency risk.

A form of vitamin E, a fat-soluble antioxidant that protects cell membrane lipids and lipoproteins from oxidation. Food sources, balance with other vitamin E forms, dietary fat quality, bile flow, and caution with high-dose supplements all matter.

The main form of fat storage and transport: blood triglycerides reflect not only dietary fat, but also liver metabolism, excess sugar and fructose, alcohol, insulin resistance, medications and genetics. They often fall on low-carb diets, but very high values require medical evaluation because of pancreatitis risk.