There are thirteen vitamins that are essential for humans.

Vitamins are divided into two categories, according to the way the body absorbs them:

• Fat- soluble vitamins (A, D, E, and K) are absorbed with the help of fats in the diet and are stored in the fats of the body. Because your body can store these vitamins for a long time, unless your diet is chronically lacking one of these, it is unusual to have a deficiency of fat-soluble vitamins.
  
  
• Water-soluble (vitamin C, and the eight B-complex vitamins), meaning they do not need fat for absorption, yet most are not stored very long in the body. (Because pantothenic acid and Biotin are found in so many foods and their deficiencies are rare, they are not included in the following list.) If there's an excess of these water-soluble vitamins, either from food or from a supplement, they are flushed through the body rapidly and are eliminated quickly in the urine.

Except for vitamin D, and a bit of vitamin K, your body cannot make vitamins. You must get them from foods or supplements. So, if your diet is deficient in one or more vitamins, your body will feel the effects of these missing essentials.

A lot of the vitamins in fruits and vegetables are lost between the farm and your plate. The longer the foods are stored before you eat them, the more nutrients are lost. Heat, light, and exposure to air all reduce the amount of vitamins, especially Vitamin C, thiamin, and folic acid.