Vitamins are organic chemicals that we all need for good health and must obtain from our diet.

Along with other essential nutrients such as dietary minerals, essential fatty acids and essential amino acids, vitamins are an important part of our diet and deficiencies can result in serious illness, and sometimes even death.

Vitamin B is a complex of several vitamins. The name arises because it was once considered a single vitamin, much like Vitamin C. Since later research has shown it is in fact a complex of chemically distinct vitamins that happen to often coexist in the same foods, the name has gradually declined in use, being replaced by the generic term "the B vitamins", the vitamin B complex, or by the specific names of each vitamin.

B1: Also known as thiamine or vitamin G, B1 is important in the metabolism of carbohydrates. Deficiency can lead to myriad problems including neurodegeneration, wasting, and death. Well-known syndromes caused by lack of thiamine due to malnutrition or a diet high in thiaminase-rich foods include Wernicke-Korsakoff syndrome and beriberi, diseases also common in chronic abusers of alcohol.

B2: Also known as riboflavin, B2 supports energy production and is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Milk, cheese, leafy green vegetables, liver, yeast, almonds and mature soybeans are good sources of B2.

B3: Also known as niacin or vitamin P, B3 plays an essential role in energy metabolism in the living cell. It's also been used to treat schizophrenia and other mental illnesses. Severe lack of niacin causes the deficiency disease pellagra, whereas a mild deficiency slows down the metabolism, which in turn decreases cold tolerance and is a potential contributing factor towards obesity. Good sources of B3 are kidney, brewer's yeast, chicken, salmon, eggs, nuts, legumes, leafy vegetables, mushrooms and sweet potatoes.

B5: Also known as pantothenic acid, B5 is needed to break down carbohydrates, proteins, and fats.It is contained in whole grain cereals, legumes, eggs and meat. Deficiency is very rare but is more common with age. Symptoms of deficiency are highly similar to other vitamin B deficiencies. They include allergies (e. g. stuffed or runny nose), adrenal insuffiency and rheumatoid arthritis.

B6: Also known as pyridoxine and pyridoxamine. Pyroluria is one potential cause of vitamin B6 deficiency. An overdose of pyridoxine can cause a temporary deadening of certain nerves such as the proprioceptory nerves; causing a feeling of disembodiment common with the loss of proprioception.

B7: Also known as biotin or vitamin H, B7 is used in cell growth, the production of fatty acids, metabolism of fats, and amino acids and also helps with the transfer of carbon dioxide. It is also helpful in maintaining a steady blood sugar level and is often recommended for strengthening hair and nails. Sources include liver and kidney, dairy products, some seafood, especially oysters, lobster, and salmon, cauliflower and egg yolk (but not egg white). Deficiency can have a very serious, even fatal, outcome if it is allowed to progress without treatment. Signs and symptoms of biotin deficiency include dry skin, seborrheic dermatitis, fungal infections, rashes, fine and brittle hair, hair loss or total alopecia.

B9: Also known as folic acid or vitamin M, B9 is essential for pregnant women as it helps prevent neural tube defects (NTDs) in the developing human foetus. It also helps prevent changes to DNA that may lead to cancer. Both adults and children need folate to make normal red blood cells and prevent anaemia. Leaf vegetables such as spinach and turnip greens, dry beans and peas, fortified cereal products, and some other fruits and vegetables are rich food sources of folate.

B12: Also known as cyanocobalamin, B12 is needed for nerve cells and red blood cells, and to make DNA. In nature, B12 is solely produced by bacteria found in animals (including humans), so that dirt could actually be considered a natural source of B12. But if you don't fancy eating dirt - milk and eggs will suffice. Deficiency is the cause of several forms of anaemia.

Vitamin K is mostly required for blood coagulation. Normally it is produced by bacteria in the intestines, and dietary deficiency is extremely rare unless the intestines are heavily damaged. Good sources are green leafy vegetables.