What are vitamins?

A vitamin is an organic compound and a vital nutrient that an organism requires in limited amount. They are about thirteen vitamins that are recognized at the present. Each vitamin are classified by their biological and chemical activity, not their structure.  Below is a list of each vitamin and biological breakdown of their compounds.

Vitamin generic descriptor name	Vitamer chemical name(s) (list not complete)	Solubility	Recommended dietary allowances (male, age 19–70)[7]	Deficiency disease	Upper Intake Level (UL/day)[7]	Overdose disease	Food sources
Vitamin A	Retinol, retinal, and four carotenoids including beta carotene	Fat	900 µg	Night blindness,Hyperkeratosis, andKeratomalacia[8]	3,000 µg	Hypervitaminosis A	LIVER, orange, ripe yellow fruits, leafy vegetables, carrots, pumpkin, squash, spinach, fish, soy milk, milk
Vitamin B1	Thiamine	Water	1.2 mg	Beriberi, Wernicke-Korsakoff syndrome	N/D[9]	Drowsiness or muscle relaxation with large doses.[10]	Pork, oatmeal, brown rice, vegetables, potatoes, LIVER, eggs
Vitamin B2	Riboflavin	Water	1.3 mg	Ariboflavinosis,Glossitis, Angular stomatitis	N/D		Dairy products, bananas, popcorn, green beans, asparagus
Vitamin B3	Niacin, niacinamide	Water	16.0 mg	Pellagra	35.0 mg	Liver damage (doses > 2g/day)[11] and other problems	Meat, fish, eggs, many vegetables, mushrooms, tree nuts
Vitamin B5	Pantothenic acid	Water	5.0 mg[12]	Paresthesia	N/D	Diarrhea; possibly nausea and HEARTBURN.[13]	Meat, broccoli, avocados
Vitamin B6	Pyridoxine,pyridoxamine,pyridoxal	Water	1.3–1.7 mg	Anemia[14] peripheral neuropathy.	100 mg	Impairment ofproprioception, nerve damage (doses > 100 mg/day)	Meat, vegetables, tree nuts, bananas
Vitamin B7	Biotin	Water	30.0 µg	Dermatitis, enteritis	N/D		Raw egg yolk, LIVER, peanuts, leafy green vegetables
Vitamin B9	Folic acid, folinic acid	Water	400 µg	Megaloblastic anemiaand Deficiency during pregnancy is associated with birth defects, such as neural tube defects	1,000 µg	May mask symptoms of vitamin B12 deficiency; other effects.	Leafy vegetables, pasta, bread, cereal, LIVER
Vitamin B12	Cyanocobalamin,hydroxycobalamin,methylcobalamin	Water	2.4 µg	Megaloblastic anemia[15]	N/D	Acne-like rash [causality is not conclusively established].	Meat and other animal products
Vitamin C	Ascorbic acid	Water	90.0 mg	Scurvy	2,000 mg	Vitamin C megadosage	Many fruits and vegetables, LIVER
Vitamin D	Cholecalciferol (D3),Ergocalciferol (D2)	Fat	10 µg[16]	Rickets andOsteomalacia	50 µg	Hypervitaminosis D	Fish, eggs, LIVER, mushrooms
Vitamin E	Tocopherols,tocotrienols	Fat	15.0 mg	Deficiency is very rare;sterility in males andabortions in females, mild hemolytic anemiain newborn infants.[17]	1,000 mg	Increased CONGESTIVE HEART FAILUREseen in one large randomized study.[18]	Many fruits and vegetables, nuts and seeds
Vitamin K	phylloquinone,menaquinones	Fat	120 µg	Bleeding diathesis	N/D	Increases coagulation in patients taking warfarin.[19]	Leafy green vegetables such as spinach, egg yolks, liver

Health effects

Vitamins are essential for the normal growth and development of a multicellular organism. Using the genetic blueprint inherited from its parents, a fetus begins to develop, at the moment of conception, from the NUTRIENTS it absorbs. It requires certain vitamins and minerals to be present at certain times. These NUTRIENTS facilitate the chemical reactions that produce among other things, skin, bone, and muscle. If there is serious deficiency in one or more of these nutrients, a child may develop a de