What is clinical nutrition?

Clinical nutrition is the study of the relationship between food and a healthy body. More specifically, it is the science of nutrients and how they are digested, absorbed, transported, metabolized, stored, and eliminated by the body. Besides studying how food works in the body, nutritionists are interested in how the environment affects the quality and safety of foods, and what influence these factors have on health and disease.

What are nutrients?


Nutrients are substances that the body needs to live and grow. The body requires more than 45 nutrients, and the ways they are used are as different as the molecules, cells, and tissues they help to create. Carbohydrates, proteins, and fats -- called macronutrients -- are broken down (metabolized) to provide energy. Vitamins and minerals -- called micronutrients -- are not used for energy themselves, but are needed to help macronutrients be used for energy.

What is the history of clinical nutrition?

The study of nutrition dates back to the 18th century, when the French chemist Lavoisier discovered a relationship between our metabolism of food and the process of breathing. By the early 20th century, scientists had found that diseases -- such as beri beri, rickets, scurvy, and pellagra -- were associated with certain diets. By 1912, the Polish chemist Casimir Funk had found a substance (vitamin B1) that actually prevented beri beri, and he named it "vitamine." Later it was found that these diseases were caused by the lack of specific nutrients -- vitamin B1 (thiamine), vitamin D, vitamin C, and vitamin B3 (niacin) respectively.

Researchers and scientists continue to find out more about how individual nutrients can help prevent and treat disease. But they are also learning how whole foods may allow nutrients to work together. For example, antioxidants like beta carotene, selenium, vitamin E, and vitamin C, when consumed in foods, appear to protect against the development of heart disease, cancer, and other chronic degenerative diseases.

The old RDAs have been replaced by Dietary Reference Intakes (DRIs), which show how much of a nutrient we need every day to maximize health and lower the risk of chronic disease (in contrast to RDAs, which listed the minimum amount needed to prevent a deficiency). The field of clinical nutrition is now increasingly incorporated into mainstream medical treatment.

  What are nutritional supplements?

The term "nutritional supplement" refers to vitamins, minerals, and other nutrients that are used to support good health and treat illness. For example, plant compounds known as phytochemicals (found in tomatoes and soybeans) have powerful disease fighting properties. While it's best to get nutrients through the foods you eat, sometimes taking a supplement can help. For example, taking zinc supplements has been reported to shorten the duration of the common cold and lower the incidence of acute diarrhea in children.

                                                               How do vitamins and minerals work?

Vitamins and minerals play an essential role in the body's normal metabolism, growth, and development. For example, while a vitamin is not a source of energy by itself, it can provide the key the body needs to unlock energy stored in food. Some vitamins and minerals work together, such as the mineral zinc and vitamin A. Zinc enables the body to use vitamin A to promote good vision. Not getting enough vitamin A may lead to night blindness, a condition in which the eyes have trouble adjusting to darkness. Zinc supplementation may help prevent this condition by helping the body use vitamin A. Another example is calcium and vitamin D. Calcium, which is very important in bone and heart health, is more readily absorbed if vitamin D is also present.

Taking supplements, however, is not the answer to long term good health. Instead, combining a healthy diet with regular exercise and a positive mental attitude is the best bet for a healthy lifestyle.