B vitamins

The B vitamin complex (also called B vitamins) are a group of 8 vitamins. They have an important job in the metabolism of cells. Each B vitamin is a cofactor (a coenzyme) for some key metabolic processes or it is a precursor needed to make one.

Originally, people thought they were just different forms of one vitamin (as with Vitamin D, for example). Later it turned out that they are separate vitamins that often can be found together. They are Vitamin B1/Thiamine, Vitamin B2/Riboflavin, Vitamin B3/Vitamin P/Vitamin PP/Niacin,Vitamin B5/Pantothenic acid, Vitamin B6, Vitamin B7/Vitamin H/Biotin, Vitamin B9/Vitamin M/Vitamin B-c/Folate and Vitamin B12. They are required for growth, and proper functioning of nerves and muscles. B vitamins are found in meat, milk, whole grains and fresh vegetables.

Vitamin B deficiencies have been shown to cause the following symptoms:Bender, David A. 2009. A dictionary of food and futrition. Oxford University Press, p. 521. Berdanier, Carolyn D. et al 2007. Handbook of nutrition and food. 2nd ed, CRC Press, p. 117. 

mental problems
heart palpitations
heart arrhythmias
exhaustion
paranoia, vague fears, fear that something dreadful is about to happen, nervousness, ADD (attention deficiency), inability to concentrate
thoughts of dying
frustration
inability to sleep
restlessness
tingling in hands
tingling fingers and toes
crying spells, inability to cope
soreness all over

Well-known medical syndromes caused by thiamine deficiency are beri-beri, Wernicke–Korsakoff syndrome (WKS), and optic neuropathy.

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