Nutrients Which Can Not Be Substituted

Some nutrients are incapable of being synthesized from other chemical components, and this requires that they come from the outside.

Essential Amino Acids
They are a part of proteins, whether they be of animal or vegetable origin. There are certain amino acids which may be obtained from the essential amino acids, but the latter cannot be substituted.

Essential Fatty Acids
These are the polysaturated fatty acids (linoleic and linolenic) which are found above all in vegetable oils and oily dried foods, especially in nuts.

Vitamins and Minerals
These are found in all foods, especially in vegetables. Excess vitamins can be dangerous. An excess of vitamin A in its final state (retinol) is toxic to man. Poisoning symptoms, known as hypervitaminosis A, are: fatigue, nervousness, pain in the bones, decalcification, headaches, and dizziness.

Water
It is found in all foods but in a quantity insufficient to provide daily needs. Because of this, 6-8 cups of water should be taken daily, a quantity which, in summer time, may need to be doubled, or even more.

Fiber
Fiber is found only in plant foods, especially in whole grains, fruit and garden products. Though it is not a nutrient in the strictest sense, because it cannot be assimilated, it is indispensable for the good functioning of the organism.