# Vitamins & Supplements Guide > An independent English-language reference guide to vitamins, dietary minerals, > herbal supplements, amino acids, phytochemicals, digestive enzymes, > carbohydrates and essential fatty acids. Each article covers what the nutrient > does in the body, dietary sources, reference intakes, deficiency signs and > what is known about excess intake. Online since 2002. Editorial standard: this guide does not state that any supplement treats, prevents or cures a disease. Statements are limited to established physiological roles and to what the sources cited on each page support. Intake figures are checked against current NIH Office of Dietary Supplements guidance. Prescription medicines, controlled substances, and substances banned or restricted for use as supplements are outside the scope of this guide and are not covered. Hormones are covered only for melatonin. All articles are for general information only and are not medical advice. ## Categories - [Vitamins](https://www.vitamins-supplements.org/): Fat- and water-soluble vitamins: sources, benefits, deficiency and toxicity. - [Herbal Supplements](https://www.vitamins-supplements.org/herbal-supplements/): Traditional herbs and botanicals with their uses and side effects. - [Amino Acids](https://www.vitamins-supplements.org/amino-acids/): Essential and non-essential amino acids and their roles in the body. - [Hormones](https://www.vitamins-supplements.org/hormones/): Melatonin, and why we do not cover prescription hormones. - [Dietary Minerals](https://www.vitamins-supplements.org/dietary-minerals/): Macro and trace minerals in human nutrition. - [Phytochemicals](https://www.vitamins-supplements.org/phytochemicals/): Plant compounds with biological activity. - [Digestive Enzymes](https://www.vitamins-supplements.org/digestive-enzymes/): Enzymes that break down food into absorbable nutrients. - [Carbohydrates](https://www.vitamins-supplements.org/carbohydrates/): Sugars, starches and fibers in the diet. - [Essential Fatty Acids](https://www.vitamins-supplements.org/essential-fatty-acids/): Omega-3, omega-6 and related fatty acids. - [Nutrients](https://www.vitamins-supplements.org/nutrients/): Other nutrients and nutrition topics. - [Weight Loss](https://www.vitamins-supplements.org/weight-loss-supplements/): Weight loss supplements and how they work. ## All articles - [Alpha-lipoic acid (thioctic acid)](https://www.vitamins-supplements.org/alpha-lipoic-acid.php) - [5-Hydroxytryptophan (5-HTP)](https://www.vitamins-supplements.org/amino-acids/5-HTP.php) - [Alanine](https://www.vitamins-supplements.org/amino-acids/alanine.php) - [Arginine](https://www.vitamins-supplements.org/amino-acids/arginine.php) - [Asparagine](https://www.vitamins-supplements.org/amino-acids/asparagine.php) - [Aspartic acid](https://www.vitamins-supplements.org/amino-acids/aspartic-acid.php) - [Branched-chain amino acids (BCAAs)](https://www.vitamins-supplements.org/amino-acids/branched-chain-amino-acids.php) - [Carnosine](https://www.vitamins-supplements.org/amino-acids/carnosine.php) - [Creatine monohydrate](https://www.vitamins-supplements.org/amino-acids/creatine.php) - [Cysteine](https://www.vitamins-supplements.org/amino-acids/cysteine.php) - [Gamma-aminobutyric acid (GABA)](https://www.vitamins-supplements.org/amino-acids/GABA.php) - [Glutamine](https://www.vitamins-supplements.org/amino-acids/glutamine.php) - [Glutathione](https://www.vitamins-supplements.org/amino-acids/glutathione.php) - [Glycine](https://www.vitamins-supplements.org/amino-acids/glycine.php) - [Histidine](https://www.vitamins-supplements.org/amino-acids/histidine.php) - [Lysine](https://www.vitamins-supplements.org/amino-acids/lysine.php) - [Methionine](https://www.vitamins-supplements.org/amino-acids/methionine.php) - [Phenylalanine](https://www.vitamins-supplements.org/amino-acids/phenylalanine.php) - [Proline](https://www.vitamins-supplements.org/amino-acids/proline.php) - [Serine](https://www.vitamins-supplements.org/amino-acids/serine.php) - [Taurine](https://www.vitamins-supplements.org/amino-acids/taurine.php) - [Theanine](https://www.vitamins-supplements.org/amino-acids/theanine.php) - [Threonine](https://www.vitamins-supplements.org/amino-acids/threonine.php) - [Tryptophan](https://www.vitamins-supplements.org/amino-acids/tryptophan.php) - [Tyrosine](https://www.vitamins-supplements.org/amino-acids/tyrosine.php) - [Para-aminobenzoic acid (vitamin Bx, PABA)](https://www.vitamins-supplements.org/aminobenzoic-acid-paba.php) - [Antioxidants vs. Free radicals](https://www.vitamins-supplements.org/antioxidant.php) - [Beta-carotene (vitamin A)](https://www.vitamins-supplements.org/beta-carotene.php) - [Bioflavonoids (vitamin P)](https://www.vitamins-supplements.org/bioflavonoids.php) - [Biotin (vitamin H, vitamin B7)](https://www.vitamins-supplements.org/biotin.php) - [Chitosan weight loss supplements](https://www.vitamins-supplements.org/carbohydrates/chitosan.php) - [Chondroitin sulfate * Glucosamine](https://www.vitamins-supplements.org/carbohydrates/chondroitin-sulfate.php) - [Glucosamine * Chondroitin sulfate](https://www.vitamins-supplements.org/carbohydrates/glucosamine.php) - [Glucose](https://www.vitamins-supplements.org/carbohydrates/glucose.php) - [Heparin sodium](https://www.vitamins-supplements.org/carbohydrates/heparin.php) - [Hyaluronic acid (sodium hyaluronate)](https://www.vitamins-supplements.org/carbohydrates/hyaluronic-acid.php) - [Ribose, D-ribose](https://www.vitamins-supplements.org/carbohydrates/ribose.php) - [Carnitine (l-carnitine, vitamin Bt)](https://www.vitamins-supplements.org/carnitine.php) - [Coenzyme Q10 (ubiquinone, vitamin Q)](https://www.vitamins-supplements.org/coenzyme-Q10.php) - [Calcium supplements](https://www.vitamins-supplements.org/dietary-minerals/calcium.php) - [Chromium supplements](https://www.vitamins-supplements.org/dietary-minerals/chromium.php) - [Copper supplements](https://www.vitamins-supplements.org/dietary-minerals/copper.php) - [Iodine supplements](https://www.vitamins-supplements.org/dietary-minerals/iodine.php) - [Iron supplements](https://www.vitamins-supplements.org/dietary-minerals/iron.php) - [Magnesium supplements](https://www.vitamins-supplements.org/dietary-minerals/magnesium.php) - [Manganese supplements](https://www.vitamins-supplements.org/dietary-minerals/manganese.php) - [Molybdenum supplements](https://www.vitamins-supplements.org/dietary-minerals/molybdenum.php) - [Phosphorus supplements](https://www.vitamins-supplements.org/dietary-minerals/phosphorus.php) - [Potassium supplements](https://www.vitamins-supplements.org/dietary-minerals/potassium.php) - [Selenium supplements](https://www.vitamins-supplements.org/dietary-minerals/selenium.php) - [Zinc supplements](https://www.vitamins-supplements.org/dietary-minerals/zinc.php) - [Amylase](https://www.vitamins-supplements.org/digestive-enzymes/amylase.php) - [Bromelain](https://www.vitamins-supplements.org/digestive-enzymes/bromelain.php) - [Lactase](https://www.vitamins-supplements.org/digestive-enzymes/lactase.php) - [Lipase](https://www.vitamins-supplements.org/digestive-enzymes/lipase.php) - [Pancreatin](https://www.vitamins-supplements.org/digestive-enzymes/pancreatin.php) - [Papain](https://www.vitamins-supplements.org/digestive-enzymes/papain.php) - [Trypsin](https://www.vitamins-supplements.org/digestive-enzymes/trypsin.php) - [Conjugated linoleic acid (CLA)](https://www.vitamins-supplements.org/essential-fatty-acids/conjugated-linoleic-acid.php) - [Omega-3 fatty acids](https://www.vitamins-supplements.org/essential-fatty-acids/omega-3-fatty-acids.php) - [Omega-6 fatty acids](https://www.vitamins-supplements.org/essential-fatty-acids/omega-6-fatty-acids.php) - [Folic acid (folate, vitamin B9)](https://www.vitamins-supplements.org/folic-acid.php) - [Alfalfa herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/alfalfa.php) - [Aloe vera herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/aloe-vera.php) - [Ashwagandha herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/ashwagandha.php) - [Astragalus (Huang qi) herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/astragalus.php) - [Barberry herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/barberry.php) - [Bilberry herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/bilberry.php) - [Black cohosh herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/black-cohosh.php) - [Black walnut herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/black-walnut.php) - [Boswellia herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/boswellia.php) - [Burdock root herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/burdock-root.php) - [Calendula herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/calendula.php) - [Catnip herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/catnip.php) - [Cayenne pepper herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/cayenne-pepper.php) - [Celery seed herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/celery.php) - [Chamomile herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/chamomile.php) - [Cranberry herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/cranberry.php) - [Dandelion herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/dandelion.php) - [Devil's claw herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/devils-claw.php) - [Dong quai (Angelica sinensis) herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/dong-quai.php) - [Echinacea herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/echinacea.php) - [Elderberry herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/elderberry.php) - [Eucalyptus herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/eucalyptus.php) - [Evening primrose oil herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/evening-primrose-oil.php) - [Fenugreek herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/fenugreek.php) - [Feverfew herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/feverfew.php) - [Garlic herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/garlic.php) - [Ginger herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/ginger.php) - [Ginkgo biloba herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/ginkgo-biloba.php) - [Ginseng herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/ginseng.php) - [Goldenseal herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/goldenseal.php) - [Gotu kola herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/gotu-kola.php) - [Grape seed extract (proanthocyanidins) herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/grape-seed-extract.php) - [Green tea herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/green-tea.php) - [Guarana herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/guarana.php) - [Hawthorn herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/hawthorn.php) - [Hops herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/hops.php) - [Horse chestnut herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/horse-chestnut.php) - [Horsetail herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/horsetail.php) - [Juniper berry herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/juniper-berry.php) - [Lavender herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/lavender.php) - [Lemon balm herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/lemon-balm.php) - [Licorice herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/licorice.php) - [Milk thistle herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/milk-thistle.php) - [Mullein herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/mullein.php) - [Noni (Morinda Citrifolia) herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/noni.php) - [Passion flower herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/passion-flower.php) - [Peppermint herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/peppermint.php) - [Psyllium herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/psyllium.php) - [Red clover herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/red-clover.php) - [Reishi mushroom (Ling zhi) herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/reishi-mushroom.php) - [Rhodiola rosea herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/rhodiola-rosea.php) - [Rosemary herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/rosemary.php) - [Saw palmetto herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/saw-palmetto.php) - [Slippery elm herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/slippery-elm.php) - [Spirulina herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/spirulina.php) - [St John's Wort herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/St-Johns-Wort.php) - [Stinging nettle herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/stinging-nettle.php) - [Tea tree oil herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/tea-tree-oil.php) - [Valerian herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/valerian.php) - [Vitex (chasteberry) herbal supplement](https://www.vitamins-supplements.org/herbal-supplements/vitex.php) - [Melatonin](https://www.vitamins-supplements.org/hormones/melatonin.php) - [Inositol (vitamin Bh)](https://www.vitamins-supplements.org/inositol.php) - [Honey health benefits](https://www.vitamins-supplements.org/nutrients/honey.php) - [Proteins](https://www.vitamins-supplements.org/nutrients/proteins.php) - [S-Adenosylmethionine (SAMe)](https://www.vitamins-supplements.org/nutrients/SAMe.php) - [Pantothenic acid (vitamin B5, calcium pantothenate)](https://www.vitamins-supplements.org/pantothenic-acid.php) - [Capsaicin](https://www.vitamins-supplements.org/phytochemicals/capsaicin.php) - [Carotenoids](https://www.vitamins-supplements.org/phytochemicals/carotenoids.php) - [Chlorophyll, Chlorophyllin](https://www.vitamins-supplements.org/phytochemicals/chlorophyll.php) - [Dietary fibers](https://www.vitamins-supplements.org/phytochemicals/dietary-fiber.php) - [Lutein and zeaxanthin](https://www.vitamins-supplements.org/phytochemicals/lutein-zeaxanthin.php) - [Lycopene](https://www.vitamins-supplements.org/phytochemicals/lycopene.php) - [Resveratrol](https://www.vitamins-supplements.org/phytochemicals/resveratrol.php) - [Soy isoflavones](https://www.vitamins-supplements.org/phytochemicals/soy-isoflavones.php) - [Vitamin A](https://www.vitamins-supplements.org/vitamin-A.php) - [Vitamin B complex](https://www.vitamins-supplements.org/vitamin-B.php) - [Vitamin B1 (thiamine, thiamin)](https://www.vitamins-supplements.org/vitamin-B1-thiamine.php) - [Vitamin B12 (cyanocobalamin, cobalamin)](https://www.vitamins-supplements.org/vitamin-B12-cyanocobalamin.php) - [Vitamin B2 (riboflavin)](https://www.vitamins-supplements.org/vitamin-B2-riboflavin.php) - [Vitamin B3 (niacin, nicotinic acid, nicotinamide)](https://www.vitamins-supplements.org/vitamin-B3-niacin.php) - [Vitamin B6 (pyridoxine)](https://www.vitamins-supplements.org/vitamin-B6-pyridoxine.php) - [Vitamin C (ascorbic acid)](https://www.vitamins-supplements.org/vitamin-C.php) - [Vitamin D (calciferol)](https://www.vitamins-supplements.org/vitamin-D.php) - [Vitamin deficiencies](https://www.vitamins-supplements.org/vitamin-deficiency.php) - [Vitamin E (tocopherol)](https://www.vitamins-supplements.org/vitamin-E.php) - [Vitamin K](https://www.vitamins-supplements.org/vitamin-K.php) - [Vitamins sources, sources of vitamin supplements](https://www.vitamins-supplements.org/vitamin-sources.php)