Water-soluble (vitamins)
Vitamin B1 (Thiamine)
Vitamin B1 is involved in producing energy, as well as synthesizing DNA and RNA, the nucleic acids that carry our genetic material.
Vitamin B1 Deficiency: Symptoms include burning feet, weakness in extremities, rapid heart rate, swelling, lack of appetite, nausea, fatigue, and digestive problems.
Toxicity: None known.
Vitamin B1 Food Sources: Sunflower seeds, asparagus, lettuce, mushrooms, black beans, navy beans, lentils, spinach, peas, pinto beans, lima beans, eggplant, Brussels sprouts, tomatoes, tuna, whole wheat, soybeans [1]
Vitamin B2 (Riboflavin)
Vitamin B2 helps produce red blood cells and metabolize toxins in the liver. (It’s also what turns your pee bright yellow when you take a multivitamin!)
Vitamin B2 Deficiency: Symptoms include cracks, fissures and sores at corner of mouth and lips, dermatitis, conjunctivitis, light sensitivity (photophobia), inflammation in the mouth, anxiety, loss of appetite, and fatigue.
Toxicity: Very rare. Excess supplementation can cause liver damage.
Vitamin B2 Food Sources: Almonds, soybeans / tempeh, mushrooms, spinach, whole wheat, yogurt, mackerel, eggs, liver[2]
Vitamin B3 (Niacin)
Vitamin B3 plays a role in repairing DNA, keeping nerves healthy, and controlling cholesterol levels.
Vitamin B3 Deficiency: Symptoms include dermatitis, diarrhea, dementia, and inflammation of the stomach.
Toxicity: Very rare from foods. Supplemental nicotinic acid (a form of niacin) may cause skin flushing, itching, impaired glucose tolerance and digestive upset. Taking high doses for months at a time can cause liver cell damage.
Vitamin B3 Food Sources: Mushrooms, asparagus, peanuts, brown rice, corn, green leafy vegetables, sweet potato, potato, lentil, barley, carrots, almonds, celery, turnips, peaches, chicken meat, tuna, salmon [3]
Vitamin B5 (Pantothenic acid)
Vitamin B5 helps to form acetyl-CoA, an important molecule involved in energy production. It also helps keep skin healthy.
Vitamin B5 Deficiency: Very unlikely. Only in severe malnutrition may one notice tingling in feet.
Toxicity: Possible nausea, heartburn, and diarrhea with high-dose supplements.
Vitamin B5 Food Sources: Broccoli, lentils, split peas, avocado, whole wheat, mushrooms, sweet potato, sunflower seeds, cauliflower, green leafy vegetables, eggs, squash, strawberries, liver [4]
Vitamin B6 (Pyridoxine)
Vitamin B6 is involved in glycogen breakdown, nervous and immune system function, and the formation of neurotransmitters and steroid hormones.
Vitamin B6 Deficiency: Symptoms include inflammation of the skin and digestive system, sleeplessness, confusion, nervousness, depression, irritability, and anemia.
Toxicity: High doses of supplemental vitamin B6 may result in painful neurological symptoms.
Vitamin B6 Food Sources: Whole wheat, brown rice, green leafy vegetables, sunflower seeds, potato, garbanzo beans, banana, trout, spinach, walnuts, peanut butter, tuna, salmon, lima beans, chicken [5]
Vitamin B9 (Folate / Folic acid)
Folate helps to form new proteins and is also involved in fetal development.
Folate refers to the naturally occurring form found in foods. Folic acid is the synthetic form of the vitamin, used in most supplements and fortified foods.
Vitamin B9 Deficiency: Anemia (macrocytic / megaloblastic), low white blood cells (leukopenia), low blood platelets (thrombocytopenia), weakness, weight loss, cracking and redness of the tongue and mouth, and diarrhea. In pregnancy, there is a risk of low birth weight, preterm delivery, and neural tube defects.
Toxicity: None from food. Large doses of supplemental folic acid can mask an underlying vitamin B12 deficiency.
Vitamin B9 Food Sources: Green leafy vegetables, asparagus, broccoli, Brussels sprouts, citrus fruits, beans and legumes, whole grains, green peas, avocado, peanuts, organ meats [6]
Vitamin B12 (Cobalamin)
Vitamin B12 is involved in DNA synthesis, and also helps to form and maintain healthy blood and nerve cells. Vitamin B12 needs “intrinsic factor” (a compound secreted by the stomach during digestion) to be absorbed. We can store decades worth of this vitamin in our body—but it should still be consumed regularly.
Vitamin B12 Deficiency: Symptoms include pernicious anemia, neurological problems, mouth inflammation. Strict vegans and plant-based eaters may be more at risk.14
Toxicity: Extremely rare, even with supplementation. Only a small amount is absorbed orally, thus the potential for toxicity is low.
Vitamin B12 Food Sources: Liver, trout, salmon, tuna, haddock, egg, dairy. Vitamin B12 isn’t found in plant foods. [7]
Vitamin B7 (Biotin)
Vitamin B7 is involved in energy production, as well as DNA replication and transcription.
Biotin Deficiency: Very rare in humans. Note that raw egg whites contain avidin, a protein that binds to biotin and prevents its absorption. Regularly eating raw egg whites can cause biotin deficiency.
Toxicity: Not known.
Biotin Food Sources: Green leafy vegetables, most nuts, whole-grain breads, avocado, raspberries, cauliflower, carrots, papaya, banana, salmon, eggs [8]
Vitamin C (Ascorbic acid)
Vitamin C is probably most famous for its role in supporting the immune system. However, it also helps build collagen, keeping skin and joints healthy; synthesize norepinephrine, an adrenal hormone; and metabolize cholesterol.
Vitamin C Deficiency: Symptoms include bruising, lethargy, dental cavities, tissue swelling, dry hair, skin, and eyes, bleeding and infected gums, hair loss, joint pain, delayed wound healing, and bone fragility. Long-term deficiency results in scurvy.
Toxicity: Possible problems with very large vitamin C doses include diarrhea and a higher risk of kidney stones.
Vitamin C Food Sources: Most (fresh, raw) colorful fruits and vegetables [9]
Fat-soluble (vitamins)
Vitamin A (Retinoids and carotenoids)
The vitamin A family includes animal sources (retinol, retinal, and retinoic acid) and plant sources (carotenoids). They help maintain eye health, and support immune function and wound healing.
Vitamin A Deficiency: Difficulty seeing in dim light and rough/dry skin.
Toxicity: Hypervitaminosis A is caused by consuming excessive amounts of preformed vitamin A (found in supplements but also in animal products, like liver). Preformed vitamin A is rapidly absorbed and slowly cleared from the body. Nausea, headache, fatigue, loss of appetite, dizziness, and dry skin can result. Excess intake while pregnant can cause birth defects. Carotenoid toxicity is rare.
Vitamin A Food Sources: Liver, egg yolks, carrots, sweet potato, pumpkin, green leafy vegetables, squash, cantaloupe, bell pepper, beets [10]
Vitamin D (Ergocalciferol / cholecalciferol)
Vitamin D is actually a group of prohormones (hormone precursors). The plant form of vitamin D is called ergocalciferol (vitamin D₂) and the animal form is called cholecalciferol (vitamin D₃). Vitamin D helps with calcium absorption, immune system function, and regulating glucose tolerance.
Vitamin D Deficiency: In children a vitamin D deficiency can result in rickets, deformed bones, delayed growth, and soft teeth. In adults a vitamin D deficiency can result in low bone density and tooth decay. People with darker skin are at higher risk of deficiency.
Toxicity: We can’t get too much vitamin D from the sun; only excess supplementation. Too much vitamin D will elevate blood calcium levels and may cause loss of appetite, nausea, vomiting, excessive thirst, excessive urination, itching, muscle weakness, joint pain, and calcification of soft tissues.
Vitamin D Food Sources: Although it’s not a food, the most available and “natural” source of Vitamin D is from sunlight exposure. It’s also in fortified foods, mushrooms, salmon, mackerel, sardines, tuna, shrimp, egg yolks, and beef liver. [11]
Vitamin E (tocopherols and tocotrienols)
Vitamin E is not actually a single vitamin, but a family of eight compounds: four tocopherols and four tocotrienols. The vitamin E family are potent antioxidants, and are also involved in cell-to-cell communication.
Vitamin E Deficiency: Symptoms include muscle weakness, impaired vision, acne, red blood cell damage, and problems with muscle coordination (ataxia).
Toxicity: There is a potential for impaired blood clotting.
Vitamin E Food Sources: Green leafy vegetables, nuts and seeds, olives, avocado [12]
Vitamin K
Vitamin K is a family of vitamins that includes vitamin K₁ (the plant-based form) and vitamin K₂ (the animal-based form). Vitamin K is involved in normal blood clotting and also plays a role in keeping bones healthy.
Vitamin K Deficiency: Tendency to bleed or hemorrhage, and anemia.
Toxicity: May interfere with blood-thinning medications No known toxicity with high doses.
Vitamin K Food Sources: Broccoli, green leafy vegetables, parsley, watercress, asparagus, Brussels sprouts, green beans, green peas [13]
[2]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitb2
[3]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitb3
[4]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitb5
[5]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitb6
[6]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitb9
[7]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitb12
[8]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitb7
[9]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitc
[10]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vita
[11]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitd
[12]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vite
[13]. https://www.precisionnutrition.com/all-about-vitamins-minerals#vitk