Concept of Nutrition

 Concept of Nutrition

The concept of nutrition is not simple and is not modern. It evolved over many centuries and this was associated with man taking to sea and living away from land for considerable length of time. British sailors were called “lemines” since they took lemons with them to sea to prevent scurvy.

But unlike limes lemon contain less Vitamin C.

The isolation of these ingredients was a painful process and thankfully, all of them were discovered, before I was born and many researchers received Noble Prize for their contribution.

Nutrients fall into two categories macro-nutrients and micro-nutrients.

Macro-nutrients are Fat, Starch and Proteins.

Vitamin Classification

Vitamins are classified as either water soluble or fat soluble.

In humans there are 13 vitamins

Fat Soluble

4 in number

A

D

E

K

Water Soluble

9 in number

8 B vitamins and

Vitamin C

Water-soluble vitamins dissolve easily in water and in general, are readily excreted from the body, to the degree that urinary output is a strong predictor of vitamin consumption. Because they are not as readily stored, more consistent intake is important.

Fat-soluble vitamins are absorbed through the gastrointestinal tract with the help of lipids (fats).  Vitamins A and D can accumulate in the body, which can result in dangerous hypervitaminosis.

Fat-soluble vitamin deficiency due to malabsorption is of particular significance in cystic fibrosis.

Anti-Vitamins

Anti-vitamins are chemical compounds that inhibit the absorption or actions of vitamins. For example, avidin is a protein in raw egg whites that inhibits the absorption of biotin; it is deactivated by cooking. Pyrithiamine, a synthetic compound, has a molecular structure similar to thiamine, vitamin B1, and inhibits the enzymes that use thiamine.