Discovery of vitamins started from observation of deficiency manifestations Several mysterious and often fatal diseases which resulted from vitamin deficiencies were prevalent until the past century. Sailors on long seavoyages were often the victims. In the Orient, the disease beriberi was rampant and millions died of its strange paralysis called “polyneuritis.” In 1840,George Budd predicted that the disease was caused by the lack of some organic compound that would be discovered in “a not too distant future.”a In 1893, C. Eijkman, a Dutch physician working in Indonesia, observed paralysis in chicks fed white rice consumed by the local populace. He found that the paralysis could be relieved promptly by feeding an extract of rice polishings. This was one of the pieces of evidence that led the Polish biochemist Casimir Funk to formulate the “vitamine theory” in about 1912. Funk suggested that the diseases beriberi, pellagra, rickets,and scurvy resulted from lack in the diet of four different vital nutrients. He imagined them all to be amines, hence the name vitamine.
Vitamins differ from macronutrients- in structure, function and amounts.Vitamins are similar to macronutrients- all are vital to life, organic and available from all food groupBoth defecienies and excesses of a vitamin can affect health
Vitamin is derived from the fact that substances are needed for life(vita) and because thiamine happened to be an amine.Not all vitamins are amines or nitrogen containing compounds
Diet:Since vitamins cannot be manufactured by humans they must be obtained from food (vitamin D)Intestinal microorganisms: some vitamins can be synthesized by the intestinal microorganisms. However the quantity synthesized in this manner may not be sufficient to meet the daily requirement . (Biotin)
Average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all the individuals. The RDA is not the minimal requirement for healthy individuals; rather, it is intentionally set to provide a margin of safety for most individuals
Lack of transportDefective uptakeFailure to convert precursors
Water soluble vitamins Fat soluble vitamins
Solubility Water soluble Fat soluble
Absorption Simple Along with lipids
Storage *No storage Stored in liver
Excretion Excreted Not excreted
Excess intake Nontoxic Toxic
Deficiency Manifests rapidly Manifests slowly
Treatment Regular dietary supply Single large dose
Difference b/w water soluble & fat soluble vitaminsVITAMINS
Essential for growth,
maintenance and reproduction
Fat soluble vitamins are required for normal and colour vision, blood
clotting, bone formation and maintenance of membrane structure.
Most of the water soluble
vitamins function as coenzymes
Vitamins A and D act
as steroid hormones.
Lack of vitamin in the diet produce
characteristic deficiency symptoms
Some drugs and compounds present
in natural sources act as antivitamins.
Some vitamin analogs
are used as drugs
• MEDICAL AND BIOLOGICAL IMPORTANCE