Vitamin B3: Niacin

Vitamin B₃, or niacin, is a water soluble vitamin essential for maintaining health.

As with other water soluble vitamins niacin cannot be stored in large amounts in your body for any length of time. Your body supplies need to be replenished regularly.

However, unlike most essential vitamins which can only be sourced from dietary sources, niacin can be synthesised in your body from tryptophan.

Tryptophn is an essential amino acid: an amino acid which is not synthesised within your body, but necessary to maintain optimum metabolic function.

There are several forms of vitamin B₃. Niacin is the generic term for both nicotinic acid and nicotinamide (or niacinamide) which are metabolically active in your body.

Functions

Niacin functions as part of the coenzymes nicotinamide adenine dinucleotide (NAD) and NADP (NAD + P=phosphate).

These are essential in energy metabolism pathways required by approximately 200 enzymes.

A major function of NAD and NADH (NAD + a proton) is the transfer of electrons in the electron transport chain which produces ATP (Adenosine triphosphate) the energy molecule.

Niacin is also required for...link to the full article to learn more about vitamin B₃.