Vitamins form an essential element in our diet. Our body requires these vitamins in correct proportion for its healthy and proper functioning. They contribute to the overall growth, development and maintenance of our body.
Vitamins are “micro nutrients” required in very small quantities by our body. Though these nutrients are grouped together as vitamins, they are not similar to each other structurally or functionally.
Though some organisms synthesize vitamins, most of them depend on food as their primary source. For example, dogs and cats can synthesize vitamin C whereas human beings have to acquire it from the food they consume.
Vitamins are of two types :-
1. water soluble :-
Water soluble vitamins dissolve in water and cannot be stored in our body. They are removed by urine and hence needs to be replaced every day.
2. Fat soluble :-
Fat soluble ones dissolve in fat and can be stored in our body. They are absorbed by the intestinal tract with the help of lipids.
Our body cannot produce or manufacture all the essential vitamins by themselves. Therefore, food becomes the main source of vitamins. Most vitamins that our body depends on are obtained from the food we eat. But there are a few vitamins produced within our body like vitamin K and vitamin D. Vitamin K and biotin are produced by the micro-organisms in the intestines and vitamin D is synthesized in the skin with the help of the sun-rays that contain UV rays.
Vitamins do not yield energy like carbohydrates or fats, vitamins are essential for certain body functions. They help in carrying out certain metabolic reactions in our body. They act as catalysts as they participate and speedup the chemical reactions without themselves getting altered. For example, vitamin K helps in the clotting of blood.
Not all food items contain all the vitamins. The requirements of different vitamins by our body also vary. Our body does not require all the vitamins in equal proportions. Too much or too little intake of vitamins can cause diseases. Some of the deficiency diseases are beriberi, pellagra, scurvy and rickets. Overdose of vitamins could also cause Nausea, vomiting and diarrhea.
Apart from the dietary intake, vitamins are also available in the form of pills. But it is always best to eat healthy food and to avoid having vitamin pills.