Vitamins and minerals, explained carefully

Micronutrient guides

What essential nutrients do, where food supplies them, and when supplements, medications, pregnancy, or kidney function change the conversation.

Start with food and context. Reference intakes are population tools—not diagnoses, supplement prescriptions, or proof of deficiency. These pages use NIH Office of Dietary Supplements fact sheets as their primary reference.
Micronutrient

Potassium

Electrolyte balance, food sources, and kidney caution.

Micronutrient

Iodine

Thyroid hormones, iodized salt, and supplement caution.

Micronutrient

Choline

Cell membranes, acetylcholine, and food sources.

Micronutrient

Folate vs. folic acid

Forms, food sources, and pregnancy context.

Micronutrient

Vitamin A

Vision, immunity, carotenoids, and supplement safety.

Micronutrient

Vitamin E

Antioxidant function, foods, and medication interactions.

Micronutrient

Vitamin K

Clotting proteins, leafy greens, and warfarin consistency.

Micronutrient

Selenium

Thyroid enzymes, variable foods, and the upper limit.

Micronutrient

Copper

Iron metabolism, connective tissue, and zinc interactions.

Micronutrient

Phosphorus

Bones, ATP, food additives, and kidney context.

Micronutrient

Thiamin (B1)

Energy metabolism, foods, and deficiency context.

Micronutrient

Riboflavin (B2)

Food sources, cell metabolism, and supplement context.

Micronutrient

Niacin (B3)

Niacin equivalents, flushing, and high-dose safety.

Micronutrient

Pantothenic acid (B5)

Coenzyme A, broad food sources, and rare deficiency.

Micronutrient

Vitamin B6

Protein metabolism and high-dose nerve risk.

Micronutrient

Biotin (B7)

Food sources, hair claims, and lab-test interference.

Micronutrient

Vitamin B12

Fortified foods, vegan diets, nerves, and blood cells.

Micronutrient

Vitamin C

Collagen, food sources, immunity claims, and limits.

Micronutrient

Vitamin D

Bone health, food, sunlight, testing, and supplements.

Micronutrient

Calcium

Bone, muscle, food sources, and supplement context.

Micronutrient

Iron

Oxygen transport, athletes, testing, and overload risk.

Micronutrient

Magnesium

Enzymes, muscle and nerve function, foods, and supplements.

Micronutrient

Manganese

Enzymes, plant foods, rare deficiency, and excess.

Micronutrient

Chromium

Changing evidence, food variability, and supplement claims.

Micronutrient

Zinc

Immune function, foods, deficiency, and copper balance.

Looking for a specific function or food? Use the searchable micronutrient finder to filter the full reference by nutrient, body role, or example food source.