Vitamins are required in trace amounts – micrograms to milligrams per day, in the diet for health, growth and reproduction.
The vitamins that are soluble in lipid solvents are absorbed and transported by conventional lipid transport processes.
For water soluble vitamins, their respective aqueous solubility coefficients, in part, dictate relative absorption.
They contribute to good health by regulating the metabolism and assisting the biochemical processes that release energy from digested food.
By and large, vitamins functions as coenzymes. Enzymes are essential chemicals that are foundation of human bodily. Enzymes are catalysts or activators in the chemical reactions that are continually taking within the body.
In additions to their role as coenzymes, some vitamins have other functions. For example, vitamin E acts as an antioxidants, and active vitamin D functions as a hormone.
Although vitamins are essential in the diet for normal health, they may have adverse physiological effects when consumed in excessive amounts.
Functions of vitamin in general
