Vitamins are the substances that are indispensable for human health and development. They are responsible for functioning of the immunity and preventing serious diseases. In fact, there are 13 vitamins such as thiamine, niacin, pantothenic acid, biotin, folate, B-12, B-6, riboflavin, A, C, D, E and K. Each vitamin has its own role. The deficiency of one of them may lead to some illness (Institute of Medicine, Food and Nutrition Board., 2000). For instance, if somebody does not get enough vitamin D, he or she can suffer from rickets. A lot of vitamins prevent health problems. For example, vitamin A helps to avoid night blindness.
Vitamins are often classified according to theirs solubility being fat-soluble and water-soluble. The fat-soluble vitamins are absorbed with the ingested dietary fats by small intestines (Escott-Stump S., 2008). One cannot absorb them if he or she does not ingest them with some fat. Fat-soluble vitamins are divided into:
- Vitamin A. It is necessary for the process of vision, especially for light and dark adjustment. In addition, it is essential for tissue growth, in particular for skin and mucous membranes. The possible results of vitamin A deficiency are night blindness, xerophthalmia, inclination for epithelial infections and changes in skin. Furthermore, the excess of vitamin A intake can be very toxic. It can lead to vomiting, abdominal pain, nausea, mental illness, muscle pain, hair loss and blurry vision. The sources of vitamin A are: liver, butter, milk, egg yolk, vegetables and fruits.
- Vitamin D. It helps to absorb calcium and phosphorus. Also, it is known for calcification of bones. The deficiency of vitamin D causes rickets, inappropriate teeth development and faulty bone growth. When taking vitamin D in great amounts it can be toxic and lead to weakness, anorexia, nervous breakdown, nausea, insomnia, vomiting and renal failure. A great deal of vitamin D is contained in fortified milk, fish oils and sunshine (Escott-Stump S., 2008).
- Vitamin E. It works as anti-oxidant and as a protector of easily oxidized materials. It also provides with the normal growth of the organism and facilitates in animal reproduction. The results of vitamin E deficiency can be fatty acids, red blood cells failure, anemia and sterility. Vegetable oil and vegetable greens are held in vitamin E.
- Vitamin K. It is responsible for normal blood clotting. It also plays an important role in bone health. The vitamin K deficiency is rare to observe, however, it leads to bleeding proneness and hemorrhagic illnesses. An excessive intake of vitamin K happens to show allergic reactions, such as cytotoxicity in liver and hemolytic anemia. Good sources of vitamin K are cheese, egg yolk, chicken liver, cabbage, broccoli, spinach, butter and asparagus.
To the contrary, water-soluble vitamins are dissolved in water and eliminated in urine. The can be easily diminished during food storage or cooking, that is why it is necessary to store and prepare food properly in order to eliminate the chance of vitamin loss. Vitamin C and the group of vitamins B belong to the water-soluble vitamins (Anderson J. and Young L., 2012).
- Vitamin C. According to scientists, it is one of the safest nutrients. It helps with the immune system deficiencies, cardiovascular illnesses, prenatal health issues, diseases related to eyes and skin wrinkling. As a result of its deficiency, one can suffer from hemorrhage, depression, fever, anemia and tendency to bruise easily. There are a lot of products were people can find the vitamin C. For instance, citruses, cabbage, green peppers, melons, potatoes, strawberries, tomatoes, broccoli (Escott-Stump S., 2008).
- Thiamin (B-1). It guarantees the normal growth of the organism, regular function of heart, muscles and nerves. The vitamin B-1 deficiency leads to the loss of appetite, indigestion, gastric distress, heart failure, fatigue and even paralysis. One can find thiamin in meat, nuts, peas, whole grains, yeast, pork, milk and chocolate.
- Riboflavin (B-2). It facilitates in normal growth and vigor of the organism. It also plays a crucial role in energy metabolism. The deficiency of riboflavin causes glossitis, eye irritation, skin eruption, wound aggravation and fractures at corners of the mouth. The food which is rich in riboflavin is milk, cereals and liver.
- Niacin (B-3). It leads to a normal growth of the organism, healthy skin, stomach, intestines and nervous system. The shortage of niacin results into lack of energy, weakness, dermatitis, and loss of appetite. The usual sources of niacin are peanuts, grains, avocado, eggs, potatoes, and poultry.
- Pyridoxine (B-6). An appropriate intake of B-6 vitamin gives rise to brain activity, amino acid metabolism, haem formation and protein synthesis. The deficit of pyridoxine causes anemia, convulsions, neuritis and high irritability. A great deal of pyridoxine is contained in whole grains, bananas, avocados, meat and nuts.
- Pantothenic acid. It is notable for fat, haem and cholesterol formation and also for amino acid activation. The cases of pantothenic acid deficiency are very rare and not thoroughly scrutinized. Though some insufficiency is obvious, such as numbness, muscle cramps and paresthesia. The elements of pantothenic acid can be seen in mushrooms, avocados, broccoli, poultry, eggs and sweet potatoes (Anderson J. and Young L.,2012).
- Folic acid. Generally, it is responsible for red blood cells growth and development. The absence of folic acid may lead to some types of anemia, diarrhea, glossitis, depression and some brain defects, especially during pregnancy. One can find folic acid in liver, eggs, asparagus, beets, broccoli, and oranges.
- Cobalamin (B-12). The usual functions of vitamin B-12 are formation of the normal red blood cells and nerve growth. The shortage of B-12 leads to different types of anemia, fatigue, problems with memory and depression. The sources of vitamin B-12 are found in liver, cheese, eggs, milk, and shellfish (Anderson J. and Young L., 2012).
All in all, vitamins are vital for the growth and development of the human organism. One of the best ways of getting an appropriate amount of vitamins is to follow a well-balanced diet with a big variety of food. The importance of daily vitamins intake is very high since they improve such body functions as cell growth, hormone synthesis, blood cell production, energy metabolism, nervous, immune and reproductive systems. However, one should keep in mind that high doses of some of these vitamins can be poisonous. The most important here is to get am appropriate amount of vitamins through healthy food.