SuppMap
Nutrient Guides

One clear page for every nutrient on the Daily Value chart.

Each guide explains why the nutrient matters, where food sources usually come from, what low intake can look like, and where high-dose supplements can cross into risk.

Built from the same Daily Value targets SuppMap uses in the app.Written from official NIH, FDA, and National Academies references.

Fat-soluble vitamins

Stored more readily in the body, so supplement dose matters more when intake climbs.

Fat-soluble vitaminAdults/Children 4+ DV 900 mcg

Vitamin A

Supports vision, immune defenses, and healthy growth.

Vitamin A helps your eyes adapt to low light and supports immune function, reproduction, and normal growth and development. It also helps the heart, lungs, and other organs work the way they should.

Common food sources

Liver and fish liver oils • Eggs and dairy products

High-dose note

Adult upper limit: 3,000 mcg RAE/day. This limit applies to preformed vitamin A from retinol and related forms. It does not apply to beta-carotene from foods, but beta-carotene supplements are not a good choice for smokers.

Read Guide
Fat-soluble vitaminAdults/Children 4+ DV 20 mcg

Vitamin D

Helps your body absorb calcium and supports bone and muscle health.

Vitamin D helps your body absorb calcium and phosphorus, which makes it central to healthy bones and teeth. It also supports muscle function, nerve signaling, and immune health.

Common food sources

Fatty fish such as salmon, trout, and tuna • Fortified milk, plant milks, cereals, and some yogurts

High-dose note

Adult upper limit: 100 mcg/day (4,000 IU/day). Toxicity is usually tied to high supplemental intake rather than the vitamin D your body makes from sunlight.

Read Guide
Fat-soluble vitaminAdults/Children 4+ DV 15 mg

Vitamin E

Acts as an antioxidant and helps protect cells from oxidative damage.

Vitamin E is an antioxidant that helps protect cells from oxidative damage. It also supports immune function and helps blood vessels work normally.

Common food sources

Sunflower seeds, almonds, peanuts, and hazelnuts • Sunflower, safflower, and wheat germ oils

High-dose note

Adult upper limit: 1,000 mg/day. The upper limit is based on bleeding risk, so this is one nutrient where megadosing deserves real caution.

Read Guide
Fat-soluble vitaminAdults/Children 4+ DV 120 mcg

Vitamin K

Best known for its role in normal blood clotting and bone proteins.

Vitamin K is required to make proteins involved in blood clotting, and it also helps activate proteins that support bone health.

Common food sources

Kale, spinach, collards, and other leafy greens • Broccoli and Brussels sprouts

High-dose note

No tolerable upper intake level has been set, but that does not mean intake should be erratic when you use anticoagulants.

Read Guide

Water-soluble vitamins

These vitamins help release energy from food and support nerves, blood cells, skin, and tissue repair.

Water-soluble vitaminAdults/Children 4+ DV 90 mg

Vitamin C

An antioxidant that helps with collagen, healing, and iron absorption.

Vitamin C acts as an antioxidant, helps your body make collagen, supports wound healing, and improves absorption of non-heme iron from plant foods. It also supports normal immune function.

Common food sources

Citrus fruits, strawberries, kiwi, and tomatoes • Bell peppers, broccoli, Brussels sprouts, and potatoes

High-dose note

Adult upper limit: 2,000 mg/day. The adult upper limit is meant to reduce gastrointestinal side effects and other risks from high-dose supplements.

Read Guide
B vitamin (vitamin B1)Adults/Children 4+ DV 1.2 mg

Thiamin

Helps your cells turn carbohydrates into usable energy.

Thiamin helps cells turn carbohydrates into energy and is important for normal nerve, muscle, and heart function.

Common food sources

Pork and trout • Beans, lentils, and peas

High-dose note

No tolerable upper intake level has been established because harmful effects from excess thiamin have not been confirmed.

Read Guide
B vitamin (vitamin B2)Adults/Children 4+ DV 1.3 mg

Riboflavin

Supports energy production, cell growth, and normal development.

Riboflavin helps break down food and supports energy production, cell growth, and normal development. It also helps other vitamins do their jobs.

Common food sources

Milk, yogurt, and eggs • Lean meats and mushrooms

High-dose note

No tolerable upper intake level has been set because adverse effects from excess riboflavin have not been established.

Read Guide
B vitamin (vitamin B3)Adults/Children 4+ DV 16 mg

Niacin

Helps the nervous system, skin, and digestive system use energy from food.

Niacin helps the body turn food into energy and supports the nervous system, skin, and digestive system.

Common food sources

Poultry, beef, fish, and peanuts • Brown rice and some mushrooms

High-dose note

Adult upper limit: 35 mg/day. This upper limit is intended to reduce flushing and applies to niacin from supplements and fortified foods, not naturally occurring niacin in foods.

Read Guide
B vitaminAdults/Children 4+ DV 1.7 mg

Vitamin B6

Helps make neurotransmitters, hemoglobin, and many enzyme reactions work.

Vitamin B6 is involved in more than 100 enzyme reactions, many of them related to protein metabolism. It also helps make hemoglobin and neurotransmitters and supports immune function.

Common food sources

Chickpeas, potatoes, and bananas • Tuna, salmon, poultry, and organ meats

High-dose note

Adult upper limit: 100 mg/day. The upper limit exists because vitamin B6 toxicity is a real supplement problem, especially when high doses are taken for months.

Read Guide
B vitamin (vitamin B9)Adults/Children 4+ DV 400 mcg

Folate

Essential for DNA synthesis, cell division, and healthy pregnancy.

Folate helps the body make DNA and other genetic material and is needed for cell division and red blood cell formation. It is especially important before and during early pregnancy to reduce the risk of neural tube defects.

Common food sources

Spinach, romaine, asparagus, and other leafy or green vegetables • Beans, peas, lentils, and citrus fruits

High-dose note

Adult upper limit: 1,000 mcg/day. This upper limit applies to folic acid from supplements and fortified foods, not naturally occurring folate in foods.

Read Guide
B vitaminAdults/Children 4+ DV 2.4 mcg

Vitamin B12

Needed for healthy nerves, DNA, and red blood cell formation.

Vitamin B12 helps form red blood cells, supports nerve function, and is required for DNA production.

Common food sources

Fish, meat, poultry, eggs, and dairy foods • Fortified breakfast cereals and plant milks

High-dose note

No tolerable upper intake level has been established because vitamin B12 has not been shown to cause harm at high intakes in healthy people.

Read Guide
B vitamin (vitamin B7)Adults/Children 4+ DV 30 mcg

Biotin

Helps enzymes process fats, carbohydrates, and proteins.

Biotin helps enzymes break down fats, carbohydrates, and proteins. It also supports gene regulation and cell signaling.

Common food sources

Egg yolks, salmon, pork, and liver • Nuts, seeds, and legumes

High-dose note

No tolerable upper intake level has been established, but the lab-test interaction risk is a major real-world safety issue.

Read Guide
B vitamin (vitamin B5)Adults/Children 4+ DV 5 mg

Pantothenic acid

Helps your body make coenzyme A and release energy from food.

Pantothenic acid helps your body make coenzyme A, which is needed to release energy from food and to synthesize fatty acids, cholesterol, and some hormones.

Common food sources

Chicken, beef, organ meats, and eggs • Mushrooms, avocados, potatoes, and sunflower seeds

High-dose note

No tolerable upper intake level has been established, but more is not necessarily helpful once you meet your needs.

Read Guide

Vitamin-like

These nutrients travel with the vitamins on the Daily Value chart even though they are not all technically vitamins.

Essential nutrient often grouped with vitaminsAdults/Children 4+ DV 550 mg

Choline

Supports cell membranes, acetylcholine, liver function, and early brain development.

Choline is needed to make phospholipids in cell membranes, the neurotransmitter acetylcholine, and compounds that help move fat out of the liver. It is especially important during pregnancy and early development.

Common food sources

Eggs, especially yolks • Beef, liver, chicken, and fish

High-dose note

Adult upper limit: 3,500 mg/day. The upper limit is meant to reduce side effects from excessive supplemental intake rather than normal food intake.

Read Guide

Major minerals & electrolytes

These nutrients do a lot of the body's structural and fluid-balance work, so both low intake and imbalance matter.

Major mineralAdults/Children 4+ DV 1300 mg

Calcium

Builds and maintains bones while supporting muscles, nerves, and blood vessels.

Calcium is the most abundant mineral in the body and is essential for strong bones and teeth. It also helps muscles contract, nerves send signals, blood vessels move blood, and hormones get released when needed.

Common food sources

Milk, yogurt, and cheese • Canned sardines and salmon with bones

High-dose note

Adult upper limit: 2,000-2,500 mg/day. The adult upper limit is 2,500 mg/day for ages 19-50 and 2,000 mg/day for ages 51 and older.

Read Guide
Major mineralAdults/Children 4+ DV 1250 mg

Phosphorus

Supports bones, cell membranes, and the energy molecule ATP.

Phosphorus helps build bones and teeth, forms part of cell membranes, and is essential to ATP, the molecule your cells use for energy. It also helps with acid-base balance.

Common food sources

Dairy foods, meat, poultry, and fish • Beans, nuts, and whole grains

High-dose note

Adult upper limit: 3,000-4,000 mg/day. The adult upper limit is 4,000 mg/day for ages 19-70 and 3,000 mg/day for adults over 70.

Read Guide
Electrolyte / major mineralAdults/Children 4+ DV 2300 mg

Chloride

Helps fluid balance, stomach acid production, and acid-base control.

Chloride is an electrolyte that helps maintain fluid balance, acid-base balance, and normal blood volume. It is also part of hydrochloric acid in the stomach, so it matters for digestion as well as hydration.

Common food sources

Table salt and salty processed foods • Electrolyte drinks and mixes

High-dose note

Adult upper limit: 3,600 mg/day. The National Academies list an adult upper level of 3,600 mg/day, largely because chloride intake parallels sodium intake in most diets.

Read Guide
Electrolyte / major mineralAdults/Children 4+ DV 4700 mg

Potassium

Supports fluid balance, nerve signals, muscle contraction, and healthy blood pressure.

Potassium is an electrolyte that helps nerves fire, muscles contract, and fluids stay balanced. Diets with more potassium-rich foods are also linked with healthier blood pressure.

Common food sources

Potatoes, sweet potatoes, tomatoes, and leafy greens • Beans, lentils, bananas, oranges, and dried fruit

High-dose note

No tolerable upper intake level has been established for healthy people, but excess potassium can still be dangerous when kidneys do not clear it well.

Read Guide
Major mineralAdults/Children 4+ DV 420 mg

Magnesium

Supports hundreds of enzyme reactions, including muscle and nerve function.

Magnesium is involved in more than 300 enzyme reactions and supports muscle and nerve function, blood glucose control, blood pressure regulation, and bone structure.

Common food sources

Pumpkin seeds, almonds, cashews, and peanuts • Beans, lentils, and whole grains

High-dose note

Adult upper limit: 350 mg/day from supplements and medications. This upper limit does not apply to magnesium naturally present in food.

Read Guide

Trace minerals

Needed in smaller amounts, but still essential for enzymes, thyroid function, oxygen transport, and immunity.

Trace mineralAdults/Children 4+ DV 18 mg

Iron

Carries oxygen in blood and supports energy, cognition, and immunity.

Iron is needed to make hemoglobin and myoglobin, so it helps carry and store oxygen. It also supports energy metabolism, cognition, growth, and immune function.

Common food sources

Red meat, poultry, seafood, and organ meats • Beans, lentils, tofu, spinach, and pumpkin seeds

High-dose note

Adult upper limit: 45 mg/day. The upper limit exists because excessive iron can be harmful even though deficiency is common.

Read Guide
Trace mineralAdults/Children 4+ DV 150 mcg

Iodine

Needed to make thyroid hormones that guide growth and metabolism.

Iodine is required to make thyroid hormones, which influence growth, brain development, temperature regulation, and metabolism.

Common food sources

Iodized table salt • Seafood, seaweed, dairy foods, and eggs

High-dose note

Adult upper limit: 1,100 mcg/day. Iodine has a real upper limit because both too little and too much can disturb thyroid function.

Read Guide
Trace mineralAdults/Children 4+ DV 11 mg

Zinc

Helps immunity, wound healing, growth, and sense of taste.

Zinc supports immune function, wound healing, DNA and protein synthesis, growth, and your sense of taste and smell.

Common food sources

Oysters and other shellfish • Red meat, poultry, and dairy foods

High-dose note

Adult upper limit: 40 mg/day. The upper limit exists because long-term excess zinc can create nutrient imbalance, especially with copper.

Read Guide
Trace mineralAdults/Children 4+ DV 55 mcg

Selenium

Supports thyroid hormone metabolism and antioxidant defenses.

Selenium is part of several selenoproteins that support antioxidant defenses, thyroid hormone metabolism, reproduction, and DNA synthesis.

Common food sources

Brazil nuts • Seafood, meat, and poultry

High-dose note

Adult upper limit: 400 mcg/day. Selenium is one of the trace minerals where excess intake can become a real supplement problem.

Read Guide
Trace mineralAdults/Children 4+ DV 0.9 mg

Copper

Helps with iron metabolism, energy production, and connective tissue.

Copper helps the body use iron, supports energy production, and contributes to connective tissue, nervous system, and immune health.

Common food sources

Shellfish and organ meats • Nuts, seeds, and cocoa

High-dose note

Adult upper limit: 10 mg/day. Copper and zinc balance each other in practice, so excess or deficiency in one can influence the other.

Read Guide
Trace mineralAdults/Children 4+ DV 2.3 mg

Manganese

Supports metabolism, bone formation, and antioxidant enzymes.

Manganese helps enzymes involved in metabolism, bone formation, and antioxidant defenses work properly.

Common food sources

Whole grains and cereals • Nuts, seeds, beans, and lentils

High-dose note

Adult upper limit: 11 mg/day. The upper limit exists because manganese can accumulate and affect the nervous system when intake is excessive.

Read Guide
Trace mineralAdults/Children 4+ DV 35 mcg

Chromium

Helps insulin work and supports normal carbohydrate and fat metabolism.

Chromium enhances the action of insulin and is involved in normal carbohydrate, fat, and protein metabolism.

Common food sources

Meat, poultry, and seafood • Whole grains and some fortified products

High-dose note

No tolerable upper intake level has been established because consistent harm from dietary chromium has not been confirmed.

Read Guide
Trace mineralAdults/Children 4+ DV 45 mcg

Molybdenum

Helps enzymes process sulfur compounds and other metabolic byproducts.

Molybdenum is a cofactor for enzymes that help process sulfur-containing amino acids and other compounds the body needs to break down.

Common food sources

Beans, peas, lentils, and soy foods • Whole grains and grain products

High-dose note

Adult upper limit: 2,000 mcg/day. Molybdenum is needed only in tiny amounts, so there is little upside to large supplemental doses.

Read Guide