The vast majority of vitamins are essential nutrients needed in small quantities, but must be made through a rich and balanced diet because our body can not synthesize them.

However, there are exceptions, such as vitamin D, which is formed in the skin of niacin or nicotinic acid, formed in liver from an essential amino acid (tryptophan) and vitamin K synthesized by bacteria from the intestinal flora.

2. Functions of vitamins
Vitamins are not used as fuel and provide no energy. However, their presence is essential for the agency to adopt and utilize the energy it needs and to provide other nutrients in the diet as carbohydrates, lipids and proteins.

In addition, vitamins help regulate the nervous system, as well as processes involved in formation of genetic material, protein, red blood cells and hormones.

The lack thereof may cause complex disorders and diseases, most of which are corrected with an adequate supply of them.

3. Where can we find?
No single food contains all vitamins. However, virtually all foods provide vitamins, to a greater or lesser number and to a greater or lesser amount. Although fruits and vegetables are major sources of the same.

To avoid the loss of some, we eat food as fresh as possible, avoid over-cook the vegetables and cooking water reuse of the same for the preparation of sauces and soups, to realize its value nutritious.

It is necessary therefore the combination of different food groups (grains, meats, fish, eggs, dairy, fruits, vegetables and vegetable fats and oils) to get through a varied and balanced diet to meet the body’s vitamin needs.

4. Nutritional Needs
In healthy subjects, a mixed diet is balanced enough to satisfy their vitamin needs being unnecessary complex vitamin supplementation.

However, the needs of each vitamin can vary with age, weight, physiological state and even by the influence of other compounds present in the diet.

Keep in mind that in some stages or physiological conditions needs increase. This is the case of babies and infants, children, pregnancy, lactation, old age, when following a weight loss … For example, vitamin C requirements increase during pregnancy, lactation, where smokers and people under stress.

Anyway should be cautious, and not abuse the vitamin supplements are presented as something miraculous. A balanced diet rich in itself provides the necessary nutrients for our bodies, without taking doses higher than those necessary vitamins that unless enrolled in diseases with a deficit of them.

There is nothing beneficial and may even become dangerous to our health, such as consumption of high doses of vitamin A and D.

5. Types of Vitamins
Vitamins are classified according to their solubility in two types:
- The fat-soluble, which are soluble in lipids, which are vitamins A, D, E and K, and
- The water-soluble, which are soluble in water, which are vitamin C, B vitamins, folic acid and niacin.