Vitamins are a kind of food additives that all living organisms need to continue functioning. There are 13 vitamins that have been identified as essential for human life: A, C, D, E, K and the eight B vitamins. They are termed micronutrients, meaning that your body needs only small amounts of these; however, even if the quantities needed are minute, you still need to consume vitamins continuously and regularly. Fortunately, there are many vitamin supplements available nowadays that can help you meet your nutritional needs. Vitamins are classified into two groups: water-soluble and fat-soluble. Water-soluble vitamins are easily absorbed by the body, dissolve in water and are flushed through your urine.

If you maintain a healthy diet of fresh fruits, vegetables and low-fat proteins, you may already be getting all the vitamins you need. However, there are some specific groups that may benefit from taking vitamin supplements, Child Nutrition notes. These include: pregnant or lactating women, vegans and vegetarians, people who eat less than 1,600 calories daily, aging adults, patients with medical conditions that interfere with digestion, and adults who don have enough time to eat full meals regularly. If you fall under any of these categories, seek your doctors advice before starting any vitamin supplementation regimen.

Your body needs vitamins because they fill a host of roles, such as keeping your vital systems working smoothly, protecting you from infection and disease and promoting growth and development. Without vitamins, you run the risk of a weakened immune system, fatigue, muscle pain and greater susceptibility to disease. Vitamin supplements help you out by providing a boost to the vitamins you naturally consume in your diet and filling out any remaining nutritional gaps, especially if you aren getting enough in your daily meals.

Always remember that vitamin (Foodchem) supplements are precisely that -- supplements. This means that they should not be used to replace proper meals of nutritious foods. In addition, bear in mind that they are not meant to cure, diagnose, treat or prevent diseases, the U.S. Food and Drug Administration notes. Many vitamin supplements can be harmful if combined, used in conjunction with medications, taken before or after surgery, or used as a substitute for prescription medicine. In addition, taking doses that exceed the recommended amount can have serious health consequences, depending on the supplement consumed. These effects may include vomiting, nausea, weight loss, muscle weakness and nerve damage, to name just a few.